JP4451610B2 - Piezoelectric element, inkjet head, angular velocity sensor, manufacturing method thereof, and inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To decrease variations in characteristic and to improve reliability of a piezoelectric element 20 by forming a piezoelectric substrate layer 3 comprising a perovskite type oxide excellent in crystallinity and a (001) face crystal orientation of the piezoelectric element 20. <P>SOLUTION: The manufacturing method comprises the steps of forming a first electrode layer 2 comprising an alloy of at least one type of metal selected from the group of cobalt, nickel, iron, manganese, and copper, and a noble metal, on a silicon wafer 1; forming a piezoelectric substrate layer 3 comprising rhombohedral system or tetragonal system perovskite type oxide (PZT, etc.) on the first electrdoe layer 2; and preferentially orienting the piezoelectric substrate layer 3 to the (001) face. <P>COPYRIGHT: (C)2004,JPO

Description

【０１１２】
そして、上記実施例１と同様に、上記実施例２〜実施例３９の各圧電素子における第１の電極層の膜厚測定及び組成分析を行うとともに、圧電体層の（００１）面結晶配向率を調べ、さらに、三角波電圧を印加したときの圧電素子の先端の変位量（最大変位量）を測定した。この結果を表２にまとめて示す。尚、実施例９、１７、２１、２６及び３１は、便宜的に「実施例」としているが、第１の電極層の組成分析の結果から本願発明の対象とはならなくなる。
【０１１３】
【表２】

【０１１４】
このことより、各実施例における圧電体層の（００１）面結晶配向率は、後述の比較例のものに比べてかなり高く、特に、第１の電極層においてコバルト、ニッケル、鉄、マンガン及び銅の群から選ばれた少なくとも１種の金属の含有量を２６モル％以下にすれば、確実に９０％以上になるとともに、圧電素子の先端の最大変位量も高レベルになることが判る。
【０１１５】
尚、上記実施例１〜実施例３９の各圧電素子の圧電体層は、一定組成のＰＺＴ膜としたが、Ｔｉ／Ｚｒモル比が異なる組成のＰＺＴ膜でも同様の結果が得られた。また、圧電体層としては、Ｌａを含むＰＺＴ膜（ＰＬＺＴ膜）でも、ＮｂやＭｇ等のイオンを含むＰＺＴ膜でもよくてペロブスカイト型結晶構造の酸化物膜であれば、全て、上記実施例１〜実施例３９の各圧電素子と同じように（００１）面配向膜が得られた。
【０１１６】
次に、比較例として、以下に示す圧電素子を作製した（比較例１及び比較例２）。
【０１１７】
すなわち、比較例１の圧電素子では、作製工程の一部分を特開２００１−８８２９４号公報の記載に従って圧電薄膜をスパッタ法で形成した。具体的には、まず、スパッタ装置を用いて、上記実施例１で用いたものと同様のシリコン基板を、１１００℃の電気炉に入れ、乾燥酸素を流して２２時間酸化処理し、表面層に約１μｍの酸化珪素膜を形成した。その基板の表面に、ジルコニウムをターゲットにして、酸素を導入しながら反応スパッタ法で膜厚０．４μｍの酸化ジルコニウムの薄膜を形成し（スパッタ条件：スパッタ電力２００Ｗ、真空度０．３Ｐａ）、その表面に、イリジウムをターゲットとするＲＦマグネトロンスパッタ装置を用いて、膜厚１．０μｍのイリジウム薄膜からなる第１の電極層を形成し、さらにその表面に、上記実施形態と同じステンレスマスクを用いて、チタンをターゲットとするＤＣマグネトロンスパッタ装置を使って、膜厚０．０６μｍのチタン薄膜を形成した。さらに、そのチタン膜の表面に、実施例１と同様の方法で、実施例１と同じ組成のＰＺＴ膜を形成し、さらに、実施例１と同様の膜厚０．２５μｍの白金薄膜からなる第２の電極層を形成し、その後、実施例１と同様に加工して、実施例１（図１）と同形状の圧電素子を作製した。
【０１１８】
上記比較例１の圧電素子における圧電体層のＰＺＴ膜の（００１）面結晶配向率を調べたところ、２３％であった。また、三角波電圧を印加したときの比較例１の圧電素子の先端の変位量を測定したところ、図４に示す結果となり、最大変位量は２．４μｍであった（尚、上記結晶配向率及び最大変位量の各値は、表２において上記実施例及び後述の比較例２と共に並記している）。
【０１１９】
上記比較例１の圧電素子の構成では、圧電体層の作製にスパッタ法を用いると、特開２００１−８８２９４号公報に記載されているように、圧電薄膜の結晶配向性のコントロールが困難であり、（００１）面結晶配向性の高いＰＺＴ膜が得られないことが判る。
【０１２０】
次いで、比較例２の圧電素子を作製した。この比較例２のものは、第１の電極層のイリジウム膜にコバルト等の金属を含有させない点が上記実施例のものとは異なる。すなわち、第１の電極層を形成する際、第１ターゲットのコバルトターゲットへのスパッタ電力を０Ｗにし、第２ターゲットのイリジウムターゲットへのスパッタ電力を２００Ｗにして１６分間スパッタリングする。このことで、結晶配向制御層として機能しないと考えられる厚み０．１０μｍの第１の電極層（イリジウム膜）を形成し、その他は実施例１と全く同じようにして圧電素子を作製した。
【０１２１】
上記比較例２の圧電素子における圧電体層についてＸ線回折法によって解析すると、実施例１のように（００１）面配向の薄膜になっておらず、（００１）面以外に（１１１）面や（１１０）面の強度の高い回折ピークを含むＸ線回折パターンを示し、（００１）面結晶配向率は２２％であった。これは、第１の電極層がコバルト等の金属を含有していないために、結晶配向制御層として機能しなかったからであり、これにより、その上のＰＺＴ膜の（００１）面結晶配向率が低下したと考えられる。
【０１２２】
また、三角波電圧を印加したときの比較例２の圧電素子の先端の変位量を測定したところ、最大変位量は２．３μｍであった。
【０１２３】
次に、基板として、シリコン基板（長さ１５．０ｍｍ、厚さ０．３０ｍｍ、幅３．０ｍｍの短冊平板形状）の代わりに、７００℃でも変形しない耐熱性結晶化ガラス（厚み０．３０ｍｍ：熱膨張係数８７×１０^―７／℃）からなる長さ１５．０ｍｍ、幅３．０ｍｍの短冊平板形状の基板を用いて、上記実施例１と同形状の圧電素子を実施例１と同じ方法で作製した（この圧電素子を実施例４０とする）。
【０１２４】
また、上記実施例４０と同じ基板を用いて、上記実施例７と同様にして作製した圧電素子（実施例４１）と、実施例１３と同様にして作製した圧電素子（実施例４２）と、実施例１９と同様にして作製した圧電素子（実施例４３）と、実施例３２と同様にして作製した圧電素子（実施例４４）と、上記比較例２と同様にして作製した、第１の電極層がイリジウムのみからなる圧電素子（比較例３）とを得た。
【０１２５】
上記のようにガラス基板を用いて作製した実施例４０〜実施例４４及び比較例３の各圧電素子における第１の電極層の膜厚測定及び組成分析を行うとともに、圧電体層の（００１）面結晶配向率を調べ、さらに、三角波電圧を印加したときの圧電素子の先端の変位量（最大変位量）を測定した。この結果を表３に示す。
【０１２６】
【表３】

【０１２７】
このことより、基板がシリコンと異なるガラスの場合であっても、本実施例の構成の圧電素子は、高い配向率で（００１）面に結晶配向した圧電体層を備えていて、高い圧電変位が可能になることが判る。また、基板材料の違いによって電圧印加の際の変位量は異なるが、安定した変位特性を示すことが判った。
【０１２８】
（実施形態２）
図５は、本発明の実施形態に係る他の圧電素子を示し（尚、図１と同じ部分については同じ符号を付してその詳細な説明は省略する）、上記実施形態１における圧電素子の第１の電極層２と圧電体層３との間に、配向制御層１１を設けたものである。
【０１２９】
すなわち、本実施形態の圧電素子２０は、上記実施形態１と同様に、シリコン基板１と、このシリコン基板１上に配設された積層体１０とを備えていて、その一端から３．０ｍｍまでの部分で、エポキシ系接着剤６によってステンレス支持基板５に固定されており、これにより片持ち梁が構成されている。尚、本実施形態においても、基板１は、シリコンに限るものではなく、ガラス基板や、金属基板、セラミックス基板等であってもよい。
【０１３０】
上記積層体１０は、シリコン基板１上に配設された第１の電極層２と、この第１の電極層２上に配設された配向制御層１１と、この配向制御層１１上に配設された圧電体層３と、この圧電体層３上に配設された第２の電極層４とで構成されていて、基板１上に、第１の電極層２、配向制御層１１、圧電体層３及び第２の電極層４をスパッタ法により順次成膜して積層したものである。尚、本実施形態においても、上記各膜の成膜法はスパッタ法に限らず、熱処理による結晶化工程なしに直接に結晶性薄膜を形成する成膜法（例えばＣＶＤ法等）であればよく、第２の電極層４の成膜法は、ゾル・ゲル法等であってもよい。
【０１３１】
上記第１の電極層２は、上記実施形態１と同様に、コバルトとイリジウムとの合金からなっていて、電極としての役割に加えて、配向制御層１１延いては圧電体層３の結晶配向を制御する役割をも果たす電極兼結晶配向制御層を構成している。但し、本実施形態では、コバルトの含有量は１モル％であり、厚みは０．２２μｍである。尚、本実施形態においても、第１の電極層２は、コバルト、ニッケル、鉄、マンガン及び銅の群から選ばれた少なくとも１種の金属と貴金属との合金からなっていればよく、その貴金属は、白金、イリジウム、パラジウム及びルテニウムの群から選ばれた少なくとも１種であればよい。さらに、第１の電極層２が、コバルト、ニッケル、鉄、マンガン及び銅の群から選ばれた少なくとも１種の金属と貴金属との合金以外に、その組成中に極くわずかの酸素を含む合金であってもよい。そして、コバルト、ニッケル、鉄、マンガン及び銅の群から選ばれた少なくとも１種の金属の含有量は、結晶配向を良好に制御できる点で、０を越え２６モル％以下とする。さらに、第１の電極層２の膜厚は、０．０５〜２μｍの範囲であればよい。
【０１３２】
上記配向制御層１１は、立方晶系又は正方晶系の（１００）面又は（００１）面に優先配向したペロブスカイト型酸化物からなっている。この実施形態では、チタン酸ランタン鉛（組成比Ｐｂ：Ｌａ：Ｔｉ＝１．１２：０．０８：１．００）からなり、膜厚は０．０２μｍである。この配向制御層１１は、上記第１の電極層２により結晶配向が制御されており、これにより、圧電体層３の結晶配向を制御するものである。尚、配向制御層１１を構成する材料は、チタン酸ランタン鉛に限らず、このチタン酸ランタン鉛に、マグネシウム及びマンガンの少なくとも一方を添加したものであってもよく、チタン酸ランタン鉛と同様にＰＺＴ等に比べて低温形成が可能な、ストロンチウムを含むペロブスカイト型酸化物で構成してもよい。この場合、とりわけ、チタン酸ストロンチウム（ＳｒＴｉＯ_３）が含有されていることが好ましく、このチタン酸ストロンチウムのみが含有されていてもよく、チタン酸ストロンチウムの他にチタン酸鉛やチタン酸ランタン鉛、チタン酸バリウム等が含有されていてもよい。また、配向制御層１１の膜厚は０．０１〜０．２μｍの範囲であればよい。
【０１３３】
上記圧電体層３は、上記実施形態１と同様に、菱面体晶系又は正方晶系の（００１）面に優先配向したペロブスカイト型酸化物からなっていて、厚さ２．５０μｍのＰＺＴ薄膜（Ｚｒ／Ｔｉ＝５３／４７）で構成されている。尚、本実施形態においても、Ｚｒ／Ｔｉ組成は、Ｚｒ／Ｔｉ＝５３／４７に限らず、Ｚｒ／Ｔｉ＝３０／７０〜７０／３０であればよい。また、圧電体層３の構成材料は、ＰＺＴにＳｒ、Ｎｂ、Ａｌ、Ｍｇ等の添加物を含有したもの等のように、ＰＺＴを主成分とする圧電材料であればよく、その他、Ｌａを含むＰＺＴ（すなわち、ＰＬＺＴ）であってもよい。さらに、圧電体層３の厚みは、０．５〜５．０μｍの範囲であればよい。
【０１３４】
上記第２の電極層４は、上記実施形態１と同様に、厚さ０．２５μｍの白金薄膜からなっているが、導電性材料であればよく、膜厚は０．１〜０．４μｍの範囲であればよい。
【０１３５】
そして、上記実施形態１と同様に、第１及び第２の電極層２，４にそれぞれ接続したリード線７，８を介して該第１及び第２の電極層２，４間に電圧を印加して、印加電圧と圧電素子２０の先端の変位幅との関係を測定することにより、圧電素子２０の変位特性を評価することができる。
【０１３６】
次に、上記圧電素子２０の製造方法について、図６の工程図を参照しながら説明する。
【０１３７】
まず、上記実施形態１と同様に、（００１）面が研磨された２０ｍｍ角のシリコン基板１の上に、幅５．０ｍｍで長さ１８．０ｍｍの長方形の開口部をもつステンレス製マスクを用いて、ＲＦスパッタ法（詳細条件は、後述の表４における実施例４５の欄参照）によって、コバルトを１モル％含むイリジウム膜からなる第１の電極層２を形成する（図６（ａ）参照）。
【０１３８】
続いて、幅５．０ｍｍで長さ１２．０ｍｍの長方形の開口部をもつステンレス製マスクを用いて、上記第１の電極層２の表面上に正確に、ＲＦマグネトロンスパッタ法によって、厚み０．０２μｍのチタン酸ランタン鉛膜からなる配向制御層１１を形成し、その後、この配向制御層１１の表面上に正確に、ＲＦマグネトロンスパッタ法によって、厚み２．５０μｍのＰＺＴ膜からなる圧電体層３を形成する。これら配向制御層１１及び圧電体層３の形成方法については、後で詳細に説明する。
【０１３９】
次いで、上記実施形態１と同様に、上記圧電体層３の表面上にＲＦスパッタ法によって第２の電極層４を形成して、シリコン基板１上に積層体１０が設けられた構造体２１を得る（図６（ｂ）参照）。
【０１４０】
次に、上記実施形態１と同様の形状になるように、上記構造体２１をダイシングソーで切断して、圧電素子構造体部品２２を得る（図６（ｃ）参照）。
【０１４１】
続いて、上記実施形態１と同様に、上記圧電素子構造体部品２２におけるシリコン基板１の一端部を、エポキシ系接着剤６を用いて、ステンレス支持基板５に接合し（図６（ｄ）参照）、次いで、上記圧電素子構造体部品２２において露出している第１の電極層２にリード線７を接続するとともに、第２の電極層４にリード線８を接続することで、圧電素子２０が完成する（図６（ｅ）参照）。
【０１４２】
ここで、上記配向制御層１１及び圧電体層３の形成方法について詳細に説明する。すなわち、２つの同じ構造の成膜室を有しかつ薄膜形成すべき基板を真空を破らずに一方の成膜室から他方の成膜室へ移動可能なＲＦマグネトロンスパッタ装置を用い、一方の成膜室には化学量論比のチタン酸ランタン鉛（モル比でＰｂ：Ｌａ：Ｔｉ＝０．９２：０．０８：１．００）にＰｂＯを約２０モル％過剰に加えて調合した焼結体ターゲット（組成モル比Ｐｂ：Ｌａ：Ｔｉ＝１．１２：０．０８：１．００）を取り付け、他方の成膜室にはチタン酸ジルコン酸鉛（ＰｂＺｒ_０．５３Ｔｉ_０．４７Ｏ_３）に酸化鉛（ＰｂＯ）をモル比で５モル％過剰に加えて調合した焼結体ターゲットを取り付けておき、この装置によって、上記第１の電極層２を形成したシリコン基板１に対してスパッタリングすることによって配向制御層１１及び圧電体層３の各膜を形成する。
【０１４３】
具体的には、最初に、チタン酸ランタン鉛のターゲットを取り付けた成膜室の中で、第１の電極層２を形成したシリコン基板１を予め５５０℃の温度に加熱保持し、その表面に、＜００１＞軸が表面に対して垂直方向に成長したペロブスカイト型結晶構造で過剰の鉛を含有するチタン酸ランタン鉛からなる膜厚０．０２μｍの薄膜を形成する。このとき、アルゴンと酸素との混合ガス（ガス体積比Ａｒ：Ｏ_２＝１９：１）をスパッタリングガスとして用い、そのトータルガス圧力を０．３Ｐａに保持し、３００Ｗの高周波電力を印加して１０分間スパッタリングを行う。
【０１４４】
次いで、上記配向制御層１１を形成したシリコン基板１を、真空を破らずに、チタン酸ジルコン酸鉛のターゲットを取り付けた成膜室に搬送し、その中で基板１の温度５００℃に加熱して、配向制御層１１上に膜厚２．５０μｍのＰｂ_１．００（Ｚｒ_０．５３Ｔｉ_０．４７）Ｏ_３で表記できる圧電体層３を形成する。このとき、アルゴンと酸素との混合ガス（ガス体積比Ａｒ：Ｏ_２＝１９：１）をスパッタリングガスとして用い、そのトータルガス圧力を０．３Ｐａに保持し、７００Ｗの高周波電力を印加して５０分間スパッタリングを行う。
【０１４５】
上記配向制御層１１は、上記実施形態１における圧電体層３と同様に、第１の電極層２における配向制御層１１側の表面部に点在するコバルトを核にして結晶成長し、これにより、コバルト上において（１００）面又は（００１）面に配向し易くなる。しかも、配向制御層１１をチタン酸ランタン鉛で構成することで、比較的低温で、（１００）面又は（００１）面配向膜を容易にかつ安定的に形成することができる。そして、こうして形成した配向制御層１１上にＰＺＴからなる圧電体層３を形成すれば、チタン酸ランタン鉛とＰＺＴとは結晶構造が全く同じであるために、チタン酸ランタン鉛の表面に、イオンの並び方が類似のＰＺＴがそのまま膜成長し、配向制御層１１により圧電体層３は（００１）面配向（菱面体晶系の場合には、（１００）面と（００１）面とは同じあるため、この菱面体晶系の（１００）面配向を含む）となり、圧電体層３の（００１）面配向度（菱面体晶系の（１００）面配向度）が９０％以上となる。
【０１４６】
尚、配向制御層１１において（１００）面や（００１）面に配向していない領域は、第１の電極層２の表面近傍部だけでなく、圧電体層３側の表面に存在していてもよい。このような場合であっても、配向制御層１１の層厚が０．０１μｍ以上であれば、圧電体層３側の表面の大部分は（１００）面又は（００１）面配向の領域となり、圧電体層３の（００１）面配向度を９０％以上にすることができる。
【０１４７】
図７は、上記実施形態２の圧電素子２０の変形例を示し（尚、図５と同じ部分については同じ符号を付してその詳細な説明は省略する）、シリコン基板１と第１の電極層２との間に密着層１４を配設したものである。
【０１４８】
すなわち、この変形例の圧電素子２０は、上記実施形態２のものと、密着層１４を除いて同様の構成である。但し、第１の電極層２の構成材料及び厚みが異なり、第１の電極層２は、コバルトを１４モル％含む厚さ０．１５μｍの白金膜からなっている。
【０１４９】
上記密着層１４は、シリコン基板１と第１の電極層２との密着性を高めるものであって、チタンからなり、その膜厚は０．００６μｍである。尚、密着層１４は、チタン、タンタル及びモリブデンの群から選ばれた一種からなっていればよく、膜厚は０．００５〜１μｍの範囲であればよい。
【０１５０】
この圧電素子の製造方法について、図８を参照しながら説明する。
【０１５１】
すなわち、（００１）面が研磨された２０ｍｍ角のシリコン基板１の上に、幅５．０ｍｍで長さ１８．０ｍｍの長方形の開口部をもつステンレス製マスクを用いて、ＲＦスパッタ法によって、厚さ０．００６μｍのチタン膜からなる密着層１４を形成する。このチタン膜は、基板１の温度を４００℃に保持し、スパッタリングガスとしてアルゴンガスを用い、ガス圧力を１Ｐａに保持して、スパッタ電力１００Ｗで２分間スパッタすることで形成する。そして、この密着層１４上に、上記と同じステンレス製のマスクを用いて、上記実施形態２と同様にして、コバルトを１４モル％含む白金膜からなる第１の電極層２を、厚さが０．１５μｍになるように形成する（図８（ａ）参照）。
【０１５２】
続いて、上記実施形態２と同様にして、上記第１の電極層２上に配向制御層１１を形成し、この配向制御層１１上に圧電体層３を形成し、この圧電体層３上に第２の電極層４を形成することで、シリコン基板１上に積層体１０が設けられた構造体２１が得られる（図８（ｂ）参照）。
【０１５３】
次いで、上記実施形態２と同様にして、上記構造体２１をダイシングソーで正確に切断して圧電素子構造体部品２２を作製し（図８（ｃ）参照）、その後、シリコン基板１の一端部をステンレス支持基板５に接合する（図８（ｄ）参照）。そして、第１及び第２の電極層２，４にリード線７，８をそれぞれ接続することで、圧電素子２０が完成する（図８（ｅ）参照）。
【０１５４】
このように、シリコン基板１と第１の電極層２との間に密着層１４を配設することにより、シリコン基板１と第１の電極層２との密着性を向上させることができて、圧電素子２０の製造時における膜剥離を防止することができるとともに、第１及び第２の電極層２，４間への電圧印加による作動時においても膜剥離が生じ難くなる。
【０１５５】
ここで、具体的に実施した実施例について説明する。
【０１５６】
先ず、実施例４５の圧電素子として、上記図５の圧電素子と同じものを上記と同じ製造方法で作製した。尚、その作製途中で、第１の電極層、配向制御層及び圧電体層の各膜について組成分析を行うとともに、Ｘ線回折法による解析によって圧電体層の結晶配向率を調べた。
【０１５７】
上記第１の電極層（イリジウム膜）をＸ線マイクロアナライザーで組成分析を行った結果、この膜の組成は、１モル％のコバルトを含むイリジウムであることが判った。また、配向制御層（チタン酸ランタン鉛膜）をターゲットと比較しながら、Ｘ線光電子分光（ＸＰＳ）装置で組成分析した結果、この薄膜の組成は、ターゲット組成と同組成のモル比Ｐｂ：Ｌａ：Ｔｉ＝１．１２：０．０８：１．００であった。さらに、圧電体層（ＰＺＴ膜）をＸ線マイクロアナライザーで組成分析を行った結果、ＰＺＴ膜の陽イオンの組成比はＰｂ：Ｚｒ：Ｔｉ＝１．００：０．５３：０．４７であり、Ｐｂ（Ｚｒ_０．５３Ｔｉ_０．４７）Ｏ_３で表記できる化学組成になっていることが判った。
【０１５８】
また、上記圧電体層についてＸ線回折法によって解析した結果、ペロブスカイト型の結晶構造を示し、かつ、（００１）面結晶配向率が９９．５％に優先配向した薄膜（＜００１＞軸が表面に垂直な方向を向いた構造の薄膜）であることが判った。
【０１５９】
次に、上記作製した実施例４５の圧電素子における第１の電極層と第２の電極層との間にリード線を介して０Ｖ〜−２５Ｖの三角波電圧を印加し、図５に示す座標軸のＺ軸方向に上下運動する圧電素子の先端の変位量を測定した。
【０１６０】
図９に、周波数５０Ｈｚの電圧を印加した場合における圧電素子の先端の変位量を示す。図９に示すように、０Ｖ〜−２５Ｖの電圧を印加した場合、この圧電素子の先端の最大変位量は１０．８μｍであった。
【０１６１】
また、この圧電素子における第１の電極層と第２の電極層との間に、０Ｖ〜−３０Ｖの三角波電圧を印加した場合、０Ｖ〜−４０Ｖの三角波電圧を印加した場合、及び、０Ｖ〜−５０Ｖの三角波電圧を印加した場合（いずれの場合も電圧周波数は５０Ｈｚで２時間駆動）のそれぞれについて、圧電体層のクラック発生の有無を調べたところ、クラックの発生は全く見られなかった。
【０１６２】
ここで、上記実施例４５の圧電素子と同じ条件で、シリコン基板上に第１の電極層及び配向制御層を形成したものを３個準備し、これらを用いて、上記実施例４５の圧電素子と同じＰＺＴ膜を形成した。但し、この際に、３つの基板のスパッタ時間をそれぞれ２分間、５分間、及び２０分間に選んで成膜した。このようにして形成したＰＺＴ膜の膜厚はそれぞれ０．０２μｍ、０．０９μｍ、及び０．４０μｍであった。これらのＰＺＴ膜の（００１）面結晶配向率をＸ線回折法で調べた。
【０１６３】
この結果、ＰＺＴ膜の（００１）面結晶配向率は、ＰＺＴ膜厚が０．０２μｍの場合には９３％であり、０．０９μｍの場合には９８％であり、０．４０μｍの場合には９９％であった。このことから、ＰＺＴ膜の結晶配向性は、配向制御層側表面から膜成長に伴って、しだいに（００１）面配向が優性になることが判った。
【０１６４】
次に、３元ＲＦマグネトロンスパッタ装置の各ターゲットを異なる材料に交換し、スパッタ電力及びスパッタ時間を制御するとともに、配向制御層の成膜に用いるスパッタ装置のターゲットの組成及びスパッタ時間を制御することで、組成及び膜厚がそれぞれ異なる第１の電極層及び配向制御層を有する圧電素子（実施例４６〜実施例５６）を作製した。この第１の電極層を形成するときの各ターゲットの組成、スパッタ電力及びスパッタ時間、並びに配向制御層を形成するときのターゲットの組成及びスパッタ時間を表４に示す。
【０１６５】
【表４】

【０１６６】
そして、上記実施例４５と同様に、上記実施例４６〜実施例５６の各圧電素子における第１の電極層及び配向制御層の膜厚測定及び組成分析を行うとともに、圧電体層の（００１）面結晶配向率を調べ、さらに、０Ｖ〜−２５Ｖの三角波電圧を印加したときの圧電素子の先端の変位量（最大変位量）を測定した。また、０Ｖ〜−３０Ｖの三角波電圧を印加した場合、０Ｖ〜−４０Ｖの三角波電圧を印加した場合、及び、０Ｖ〜−５０Ｖの三角波電圧を印加した場合（いずれの場合も電圧周波数は５０Ｈｚで２時間駆動）のそれぞれについて、圧電体層のクラック発生の有無を調べた。この結果を表５にまとめて示す。尚、実施例４９及び５２は、便宜的に「実施例」としているが、第１の電極層の組成分析の結果から本願発明の対象とはならなくなる。
【０１６７】
【表５】

【０１６８】
このことより、各実施例における圧電体層の（００１）面結晶配向率は、後述の比較例４のものに比べて高く、特に、第１の電極層においてコバルト、ニッケル、鉄、マンガン及び銅の群から選ばれた少なくとも１種の金属の含有量を２６モル％以下にすれば、確実に９０％以上になるとともに、圧電素子の先端の最大変位量も高レベルになることが判る。
【０１６９】
また、配向制御層として、Ｍｎ添加のチタン酸ランタン鉛膜やＭｇ添加のチタン酸ランタン鉛膜を用いた場合でも、チタン酸ランタン鉛膜を用いた実施例４５と同様の圧電素子が得られることが判る。
【０１７０】
尚、上記実施例４５〜実施例５６の各圧電素子の圧電体層は、一定組成のＰＺＴ膜としたが、Ｔｉ／Ｚｒモル比が異なる組成のＰＺＴ膜でも同様の結果が得られた。また、圧電体層としては、Ｌａを含むＰＺＴ膜（ＰＬＺＴ膜）でも、ＮｂやＭｇ等のイオンを含むＰＺＴ膜でもよくてペロブスカイト型結晶構造の酸化物膜であれば、全て、上記実施例４５〜実施例５６の各圧電素子と同じように（００１）面配向膜が得られた。さらに、配向制御層としてチタン酸ストロンチウム膜を用いた場合でも、（００１）面配向膜が得られた。
【０１７１】
次に、比較例として、以下に示す圧電素子を作製した（比較例４及び比較例５）。
【０１７２】
すなわち、比較例４の圧電素子は、第１の電極層のイリジウム膜にコバルト等の金属を含有させない点が上記実施例のものとは異なる。具体的には、第１の電極層を形成する際、第１ターゲットのコバルトターゲットへのスパッタ電力を０Ｗにし、第２ターゲットのイリジウムターゲットへのスパッタ電力を２００Ｗにして１６分間スパッタリングする。このことで、結晶配向制御層として機能しないと考えられる厚み０．１０μｍの第１の電極層（イリジウム膜）を形成し、その他は実施例４５と全く同じようにして圧電素子を作製した。
【０１７３】
上記比較例４の圧電素子における配向制御層についてＸ線回折法によって解析すると、（１００）面や（００１）面配向の薄膜にならず、（１００）面及び（００１）面以外に（１１１）面や（１１０）面の強度の高い回折ピークを含むＸ線回折パターンを示した。そして、比較例４の圧電素子における圧電体層の（００１）面結晶配向率をＸ線回折法によって調べたところ、６５％であった。これは、配向制御層の結晶配向性が悪かったために、その影響でその上のＰＺＴ膜も配向率が低下したと考えられる。
【０１７４】
また、三角波電圧を印加したときの比較例１の圧電素子の先端の変位量を測定したところ、最大変位量は７．７μｍであった。
【０１７５】
次いで、上記実施例４５のものに対して配向制御層が無い構成の圧電素子を作製した。この圧電素子は、配向制御層が無いことのみが実施例４５と異なるだけであり、その他は実施例４５と全く同じようにした。つまり、圧電体層の膜形成は基板温度を５００℃に加熱し、アルゴンと酸素との混合ガス（ガス体積比Ａｒ：Ｏ_２＝１９：１）をスパッタリングガスとして用い、そのトータルガス圧力を０．３Ｐａに保持し、７００Ｗの高周波電力を印加して５０分間スパッタリングを行って、厚み２．５０μｍのＰＺＴ膜を形成した。
【０１７６】
しかしながら、圧電体層はＸ線回折の分析から目的の圧電特性を示すペロブスカイト型結晶構造のＰＺＴ膜でなく、それよりも一般に低温でできる圧電特性を示さないパイロクロア型結晶相の鉛、チタン及びジルコンを組成にする酸化物膜（膜厚３．５μｍ）であった。したがって、配向制御層が無いと、５００℃の温度では、ペロブスカイト型結晶構造のＰＺＴ膜からなる圧電体層は形成できないことが判った。
【０１７７】
そこで、圧電体層の形成温度を６００℃にして、配向制御層が無い構成の圧電素子を作製し、この圧電素子を比較例５とした。
【０１７８】
この比較例５の（００１）面結晶配向率は１００％と極めて良好であり、０〜−２５Ｖの三角波電圧を印加したときの圧電素子の先端の変位量（最大変位量）は１２．５μｍであった。しかしながら、０〜−４０Ｖの三角波電圧を印加して駆動したときに膜面に微少クラックが入り、駆動開始から４０分後には、圧電素子の膜剥がれから破壊が起こった。これは、圧電体層の形成温度が、配向制御層がある場合に比べて１００℃高温の６００℃であるため、ＰＺＴ成膜後の室温までの冷却課程で、シリコン基板とＰＺＴ膜との熱膨張率の違いからＰＺＴ膜に、より大きな引っ張り応力が作用し、さらに駆動によりＰＺＴ膜が縮むように作動するために、膜破壊が起こったものと考えられる。
【０１７９】
次に、上記図７と同じ圧電素子を上記と同じ製造方法で作製した（これを実施例５７とする）。また、３元ＲＦマグネトロンスパッタ装置の各ターゲットを異なる材料に交換し、スパッタ電力及びスパッタ時間を制御するとともに、配向制御層の成膜に用いるスパッタ装置のターゲットの組成及びスパッタ時間を制御し、さらに密着層の成膜に用いるスパッタ装置のターゲットの組成及びスパッタ時間を制御することで、組成及び膜厚がそれぞれ異なる第１の電極層、配向制御層及び密着層を有する圧電素子（実施例５８〜実施例６４）を作製した。この第１の電極層を形成するときの各ターゲットの組成、スパッタ電力及びスパッタ時間、並びに配向制御層及び密着層の各層を形成するときのターゲットの組成及びスパッタ時間を、上記実施例５７のものと併せて表６に示す。
【０１８０】
【表６】

【０１８１】
上記実施例５７〜実施例６４の各圧電素子に対して、上記実施例４５〜実施例５６と同様の評価を行った。この結果を表７に示す。
【０１８２】
【表７】

【０１８３】
このことより、基板と第１の電極層との間に密着層を設けた場合も、第１の電極層においてコバルト、ニッケル、鉄、マンガン及び銅の群から選ばれた少なくとも１種の金属の含有量を２６モル％以下とすることで、（００１）面結晶配向率を９０％以上にすることができるとともに、圧電素子の先端の最大変位量を高レベルに維持できることが判る。
【０１８４】
また、配向制御層として、Ｍｎ添加のチタン酸ランタン鉛膜やＭｇ添加のチタン酸ランタン鉛膜を用いた場合でも、チタン酸ランタン鉛膜を用いた実施例５７と同様の特性良好な圧電素子が得られることが判る。
【０１８５】
さらに、密着層の材料として、チタンの代わりに、タンタル又はモリブデンを用いた場合でも、実施例５７と同様の圧電素子が得られることが判る。
【０１８６】
尚、上記実施例５７〜実施例６４の各圧電素子の圧電体層は、一定組成のＰＺＴ膜としたが、Ｔｉ／Ｚｒモル比が異なる組成のＰＺＴ膜でも同様の結果が得られた。また、圧電体層としては、Ｌａを含むＰＺＴ膜（ＰＬＺＴ膜）でも、ＮｂやＭｇ等のイオンを含むＰＺＴ膜でもよくてペロブスカイト型結晶構造の酸化物膜であれば、全て、上記実施例５７〜実施例６４の各圧電素子と同じように（００１）面配向膜が得られた。さらに、配向制御層としてチタン酸ストロンチウム膜を用いた場合でも、（００１）面配向膜が得られた。
【０１８７】
次に、基板として、シリコン基板（長さ１５．０ｍｍ、厚さ０．３０ｍｍ、幅３．０ｍｍの短冊平板形状）の代わりに、厚み０．３０ｍｍの硼珪酸ガラス（＃７０８９、熱膨張係数４５×１０^―７／℃）からなる長さが１５．０ｍｍ、幅が３．０ｍｍの短冊平板形状の基板を用いて、上記実施例４５と同形状の圧電素子を実施例４５と同じ方法で作製した（この圧電素子を実施例６５とする）。
【０１８８】
また、上記実施例６５と同じ基板を用いて、上記実施例４６と同様にして作製した圧電素子（実施例６６）と、実施例４７と同様にして作製した圧電素子（実施例６７）と、実施例４８と同様にして作製した圧電素子（実施例６８）と、実施例５０と同様にして作製した圧電素子（実施例６９）と、実施例５１と同様にして作製した圧電素子（実施例７０）と、実施例５３と同様にして作製した圧電素子（実施例７１）と、実施例５４と同様にして作製した圧電素子（実施例７２）と、実施例５５と同様にして作製した圧電素子（実施例７３）と、上記比較例４と同様にして作製した、第１の電極層がイリジウムのみからなる圧電素子（比較例６）とを得た。
【０１８９】
上記のように硼珪酸ガラス基板を用いて作製した実施例６５〜実施例７３及び比較例６の各圧電素子に対して、上記実施例４５〜実施例５６と同様の評価を行った。この結果を表８に示す。
【０１９０】
【表８】

【０１９１】
このことより、基板をシリコンと異なるガラスにした場合であっても、本実施例の構成の圧電素子は、高い配向率で（００１）面に結晶配向した圧電体層を備えていて、大きい圧電変位を得ることが可能になることが判る。また、基板材料の硬さの違いによって電圧印加の際の変位量は異なるが、安定した変位特性を示すことが判った。
【０１９２】
尚、上記実施例６５のものに対して配向制御層が無い構成の圧電素子を作製したが、その圧電体層はＸ線回折の分析から目的の圧電特性を示すペロブスカイト型結晶構造のＰＺＴ膜でなく、それよりも一般に低温でできる圧電特性を示さないパイロクロア型結晶構造の鉛、チタン及びジルコンを組成にする酸化物膜（膜厚３．５μｍ）であった。したがって、基板をガラスにした場合でも、配向制御層が無いと、５００℃の温度では、ペロブスカイト型結晶構造のＰＺＴ膜からなる圧電体層は形成できないことが判った。
【０１９３】
（実施形態３）
次に、本発明の圧電素子の積層膜構成を用いたインクジェットヘッドについて説明する。
【０１９４】
図１０は、本発明の実施形態におけるインクジェットヘッドを示す概略構成図である。図１０に示すように、本実施形態のインクジェットヘッド２０１は、複数個（図１０では、１０個）が列状に並んで配置された同形状のインク吐出素子２０２と、それらのインク吐出素子２０２を駆動するＩＣチップ等の駆動電源素子２０３とで構成されている。
【０１９５】
図１１は、上記各インク吐出素子２０２の構成を示す一部破断した分解斜視図である。この図１１において、Ａはガラス製の圧力室部材であって、この圧力室部材Ａには圧力室用開口部３１が形成されている。Ｂは圧力室用開口部３１の上端開口面（大きさ：短軸が２００μｍ、長軸が４００μｍの楕円形状）を覆うように配置されたアクチュエータ部であり、Ｃは圧力室用開口部３１の下端開口面を覆うように配置されたインク流路部材である。すなわち、圧力室部材Ａの圧力室用開口部３１は、その上下に位置するアクチュエータ部Ｂとインク流路部材Ｃとにより区画され、これにより圧力室３２（深さ０．２ｍｍ）が形成されている。
【０１９６】
上記アクチュエータ部Ｂは、上記圧力室３２の略真上に位置する第１の電極層３３（個別電極）を有している。また、インク流路部材Ｃには、インク供給方向に並ぶ複数個のインク吐出素子２０２の各圧力室３２間で共用される共通液室３５と、この共通液室３５を圧力室３２に連通させて、共通液室３５のインクを圧力室３２に供給するための供給口３６と、圧力室３２内のインクを吐出させるためのインク流路３７とが形成されている。さらに、Ｄはノズル板であって、このノズル板Ｄには、インク流路３７に連通するノズル孔３８（直径３０μｍ）が穿設されている。そして、上記圧力室部材Ａ、アクチュエータ部Ｂ、インク流路部材Ｃ及びノズル板Ｄが接着剤によって接着されて、インク吐出素子２０２が構成されている。
【０１９７】
本実施形態では、上記圧力室部材Ａ、アクチュエータ部Ｂ（第１の電極層３３及び圧電体層４１（図１２参照）を除く）、インク流路部材Ｃ及びノズル板Ｄは、全てのインク吐出素子２０２に亘って一体形成されたものであり、１つの圧力室３２と、この圧力室３２に対応して設けられたノズル孔３８、第１の電極層３３及び圧電体層４１とを含む部分をインク吐出素子２０２としている。尚、各インク吐出素子２０２を別個に形成してそれらを並べて結合したものであってもよい。また、インクジェットヘッド２０１は、複数個のインク吐出素子２０２で構成する必要はなく、１個のインク吐出素子２０２で構成したものであってもよい。
【０１９８】
上記駆動電源素子２０３は、ボンディングワイヤーを介して複数のインク吐出素子２０２のアクチュエータ部Ｂの各第１の電極層３３にそれぞれ接続されており、この駆動電源素子２０３から各第１の電極層３３に電圧を供給するようになっている。
【０１９９】
次に、上記アクチュエータ部Ｂの構成について、図１２を参照しながら説明する。図１２は、図１１で示すインク吐出素子２０２のアクチュエータ部ＢのXII−XII線断面図である。図１２に示すように、このアクチュエータ部Ｂは、上記の如く各圧力室３２の略真上にそれぞれ位置する第１の電極層３３と、この各第１の電極層３３上（同図では下側）に設けられた圧電体層４１と、この圧電体層４１上（同下側）に設けられ、全圧電体層４１（全インク吐出素子２０２）に共通となる第２の電極層４２（共通電極）と、この第２の電極層４２上（同下側）全体に設けられ、上記圧電体層４１の圧電効果により層厚方向に変位し振動する振動層４３とを有している。この振動体層４３も、第２の電極層４２と同様に、各インク吐出素子２０２のそれぞれの圧力室３２間で共用される（全てのインク吐出素子２０２に亘って一体形成されている）。
【０２００】
上記第１の電極層３３、圧電体層４１及び第２の電極層４２は、これらが順に積層されてなる圧電素子を構成することになる。また、振動層４３は、この圧電素子の第２の電極層４２側の面に設けられていることになる。
【０２０１】
上記第１の電極層３３は、上記実施形態１と同様に、厚さが０．１０μｍであって６モル％のコバルト（Ｃｏ）を含むイリジウム（Ｉｒ）膜からなり、電極としての役割に加えて、上記圧電体層４１の結晶配向を制御する役割をも果たす電極兼結晶配向制御層を構成している。
【０２０２】
上記圧電体層４１は、上記実施形態１と同様に、菱面体晶系又は正方晶系の（００１）面に優先配向したペロブスカイト型酸化物からなり、本実施形態においても、厚さ２．５０μｍのＰｂ（Ｚｒ_０．５３Ｔｉ_０．４７）Ｏ_３で表記されるＰＺＴ膜からなる。
【０２０３】
上記第２の電極層４２は、上記実施形態１と同様に、白金薄膜（但し、膜厚は０．１０μｍ）からなっている。
【０２０４】
上記振動層４３は、厚さ３．５μｍのクロム（Ｃｒ）膜からなっている。尚、この振動層４３の材料は、Ｃｒに限らず、ニッケル、アルミニウム、タンタル、タングステン、シリコン又はこれらの酸化物若しくは窒化物（例えば二酸化シリコン、酸化アルミニウム、酸化ジルコニウム、窒化シリコン）等であってもよい。また、振動層４３の膜厚は２〜５μｍであればよい。
【０２０５】
上記第２の電極層４２上における上記第１の電極層３３及び圧電体層４１の積層膜の周囲には、上面が第１の電極層３３の高さと同じになるようにポリイミド樹脂からなる電気絶縁有機膜４４が設けられており、この電気絶縁有機膜４４の上面には、第１の電極層３３から延びるリード線形状の金薄膜（膜厚０．１０μｍ）の引き出し電極膜４５が形成されている。
【０２０６】
次に、上記インクジェットヘッド２０１の製造方法を図１３により説明する。
【０２０７】
すなわち、まず、図１３（ａ）に示すように、縦２０ｍｍ、横２０ｍｍ、厚み０．３ｍｍのシリコン基板５１を用いて、上記実施形態１と同様にして、シリコン基板５１上に第１の電極層３３と圧電体層４１と第２の電極層４２とを順次積層して、構造体５４を得る。尚、シリコン基板５１と第１の電極層３３との間に、上記実施形態１と同様に、チタン、タンタル及びモリブデンの群から選ばれた一種からなる密着層を形成してもよい。
【０２０８】
続いて、図１３（ｂ）に示すように、上記構造体５４の第２の電極層４２上に、ＲＦスパッタ法で室温でクロム（Ｃｒ）膜（厚さ３．５μｍ）からなる振動層４３を形成する。
【０２０９】
次いで、図１３（ｃ）に示すように、上記振動層４３を形成した構造体５４を、接着剤（アクリル樹脂）５５を用いて圧力室部材Ａに接合する。このとき、上記振動層４３の第２の電極層４２とは反対側の面に、予め圧力室用開口部３１を形成した圧力室部材Ａを接合する。
【０２１０】
その後、図１３（ｄ）に示すように、プラズマ反応エッチング装置を用いて、上記シリコン基板５１をＳＦ_６ガスを用いたドライエッチングにより除去する。尚、シリコン基板５１と第１の電極層３３との間に密着層を形成した場合には、その密着層も除去する。
【０２１１】
次に、図１３（ｅ）に示すように、第１の電極層３３及び圧電体層４１の積層膜を楕円形状パターン（大きさ：短軸が１８０μｍ、長軸が３８０μｍの楕円形状）にパターンニングするために、第１の電極層３３上の非エッチング部分に、フォトレジスト樹脂膜５７を塗布する。
【０２１２】
そして、図１３（ｆ）に示すように、弱フッ酸を用いて、エッチング処理を行うことで、第１の電極層３３と圧電体層４１とをパターン化して個別化し、その後、図１３（ｇ）に示すように、レジスト剥離液で処理して、フォトレジスト樹脂膜５７を除去する。
【０２１３】
続いて、図１３（ｈ）に示すように、上記のパターン化により露出した第２の電極層４２上に、ポリイミド樹脂からなる電気絶縁有機膜４４を印刷法によって形成し、さらに、図１３（ｉ）に示すように、この電気絶縁有機膜４４の上面に、ＤＣスパッタ法で金薄膜からなるリード線形状の引き出し電極膜４５を形成し、これにより、アクチュエータ部Ｂが完成する。
【０２１４】
一方、図示は省略するが、予め共通液室３５、供給口３６及びインク流路３７を形成したインク流路部材Ｃと、予めノズル孔３８を形成したノズル板Ｄとを接着剤を用いて接着しておく。そして、上記完成したアクチュエータ部Ｂと接合された圧力室部材Ａと、ノズル板Ｄを接着したインク流路部材Ｃとのアライメント調整を行って、この両者を接着剤により接着する。こうしてインクジェットヘッド２０１が完成する。
【０２１５】
尚、上記第１の電極層３３、圧電体層４１及び第２の電極層４２は、上記実施形態１で述べた材料であれば、どれを用いても、高特性のアクチュエータ部Ｂを作製することができる。また、これら各層の厚みも、上記実施形態１で述べた範囲であればよい。
【０２１６】
上記のように構成されたインクジェットヘッド２０１においては、駆動電源素子２０３からボンディングワイヤーを介して複数のインク吐出素子２０２の各第１の電極層３３に電圧が供給され、圧電体層４１の圧電効果によって共通電極である第２の電極層４２と接合された振動層４３が変位し振動することにより、共通液室３５内のインクが供給口３６、圧力室３２及びインク流路３７を経由してノズル孔３８から吐出される。この場合、インクジェットヘッド２０１において、インク吐出素子２０２のアクチュエータ部Ｂを構成する圧電体層４１は、その結晶配向性が（００１）面に揃ったものであり、圧電変位特性も大きな値でかつ揃っていることから、大きな圧電変位（変位量）を得ることが可能で、しかも、複数個のインク吐出素子２０２間において圧電変位特性のばらつきが小さくなる。そして、圧電変位が大きいことから、インクの吐出能力が高く、また、電源電圧の調整幅にマージンを大きくとることができ、複数個のインク吐出素子２０２の個々のインクの吐出ばらつきが小さくなるように、容易にコントロールすることができる。
【０２１７】
ここで、上記の製造方法によって、２５０個の同形状のインク吐出素子２０２を有するインクジェットヘッド２０１を実際に作製し、圧電体層４１を挟む２つの電極層３３，４２に、０Ｖ〜−１０Ｖのサイン波形電圧（２００Ｈｚ）を印加して、振動層４３の層厚方向の振動振幅のばらつきを測定したところ、そのばらつきσは１．５％と極めて少ないことが判明した。
【０２１８】
（実施形態４）
図１４は、本発明の実施形態に係る他のインクジェットヘッド２０１におけるインク吐出素子２０２のアクチュエータ部Ｂを示し（尚、図１２と同じ部分については同じ符号を付してその詳細な説明は省略する）、図１２で示したもの（実施形態３）に対し、上記実施形態２のように、第１の電極層３３と圧電体層４１との間に配向制御層４６を配設したものであり、他の構成は図１２で示したものと同様である。
【０２１９】
すなわち、この実施形態では、アクチュエータ部Ｂは、各圧力室３２の略真上にそれぞれ位置する第１の電極層３３と、この各第１の電極層３３上（図１４では下側）に設けられた配向制御層４６と、この配向制御層４６上（同下側）に設けられた圧電体層４１と、この圧電体層４１上（同下側）に設けられた第２の電極層４２と、この第２の電極層４２上（同下側）全体に設けられ、上記圧電体層４１の圧電効果により層厚方向に変位し振動する振動層４３とを有している。
【０２２０】
上記第１の電極層３３、配向制御層４６、圧電体層４１及び第２の電極層４２は、これらが順に積層されてなる圧電素子を構成することになる。また、振動層４３は、この圧電素子の第２の電極層４２側の面に設けられていることになる。
【０２２１】
上記第１の電極層３３は、上記実施形態２と同様に、厚さ０．２２μｍであって１モル％のコバルト（Ｃｏ）を含むイリジウム（Ｉｒ）膜からなり、電極としての役割に加えて、上記圧電体層４１の結晶配向を制御する役割をも果たす電極兼結晶配向制御層を構成している。
【０２２２】
上記配向制御層４６は、上記実施形態２と同様に、立方晶系又は正方晶系の（１００）面又は（００１）面に優先配向したペロブスカイト型酸化物からなり、本実施形態においても、厚さ０．０２μｍのチタン酸ランタン鉛膜（組成比Ｐｂ：Ｌａ：Ｔｉ＝１．１２：０．０８：１．００）からなる。
【０２２３】
上記圧電体層４１は、上記実施形態２と同様に、菱面体晶系又は正方晶系の（００１）面に優先配向したペロブスカイト型酸化物からなり、本実施形態においても、厚さ２．５０μｍのＰｂ（Ｚｒ_０．５３Ｔｉ_０．４７）Ｏ_３で表記されるＰＺＴ膜からなる。
【０２２４】
上記第２の電極層４２は、上記実施形態２と同様に、白金薄膜（但し膜厚は、０．１０μｍ）からなっている。。
【０２２５】
上記振動層４３は、上記実施形態３と同様に、厚さ３．５μｍのクロム膜からなっている。
【０２２６】
上記第２の電極層４２上における上記第１の電極層３３及び圧電体層４１の積層膜の周囲には、上面が第１の電極層３３の高さと同じになるようにポリイミド樹脂からなる電気絶縁有機膜４４が設けられており、この電気絶縁有機膜４４の上面には、第１の電極層３３から延びるリード線形状の金薄膜（膜厚０．１０μｍ）の引き出し電極膜４５が形成されている。
【０２２７】
次に、上記インクジェットヘッド２０１の製造方法を図１５により説明する。
【０２２８】
すなわち、まず、縦２０ｍｍ、横２０ｍｍ、厚み０．３ｍｍのシリコン基板５１を用いて、上記実施形態２（又は３）と同様に、シリコン基板５１上に第１の電極層３３と配向制御層４６と圧電体層４１と第２の電極層４２とを順次積層して、構造体５４を得る（図１５（ａ）参照）。尚、シリコン基板５１と第１の電極層３３との間に、上記実施形態３で説明したように、チタン、タンタル及びモリブデンの群から選ばれた一種からなる密着層を形成してもよい。
【０２２９】
続いて、上記実施形態３と同様に、上記構造体５４の第２の電極層４２上に、ＲＦスパッタ法で室温でクロム膜（厚さ３．５μｍ）からなる振動層４３を形成し（図１５（ｂ）参照）、続いて、この振動層４３を形成した構造体５４を、接着剤５５を用いて圧力室部材Ａに接合する（図１５（ｃ）参照）。
【０２３０】
その後、上記実施形態３と同様に、上記シリコン基板５１をドライエッチングにより除去する（図１５（ｄ）参照）。尚、シリコン基板５１と第１の電極層３３との間に密着層を形成した場合には、その密着層も除去する。
【０２３１】
次に、上記実施形態３と同様に、第１の電極層３３、配向制御層４６及び圧電体層４１の積層膜をパターンニングするために、第１の電極層３３上の非エッチング部分に、フォトレジスト樹脂膜５７を塗布し（図１５（ｅ）参照）、続いて、エッチング処理を行うことで、第１の電極層３３、配向制御層４６及び圧電体層４１をパターン化して個別化し（図１５（ｆ）参照）、その後、レジスト剥離液で処理して、フォトレジスト樹脂膜５７を除去する（図１５（ｇ）参照）。
【０２３２】
続いて、上記実施形態３と同様に、上記のパターン化により露出した第２の電極層４２上に、電気絶縁有機膜４４を形成し（図１５（ｈ）参照）、さらに、この電気絶縁有機膜４４の上面に、引き出し電極膜４５を形成し（図１５（ｉ）参照）、これにより、アクチュエータ部Ｂが完成する。
【０２３３】
一方、上記実施形態３と同様に、予め共通液室３５、供給口３６及びインク流路３７を形成したインク流路部材Ｃと、予めノズル孔３８を形成したノズル板Ｄとを接着剤を用いて接着しておき、上記完成したアクチュエータ部Ｂと接合された圧力室部材Ａと、ノズル板Ｄを接着したインク流路部材Ｃとのアライメント調整を行って、この両者を接着剤により接着する。こうしてインクジェットヘッド２０１が完成する。
【０２３４】
尚、上記第１の電極層３３、配向制御層４６、圧電体層４１及び第２の電極層４２は、上記実施形態２で述べた材料であれば、どれを用いてもよく、振動層４３は、上記実施形態３で述べた材料であれば、どれを用いてもよい。また、これら各層の厚みも、上記実施形態２及び３で述べた範囲であればよい。
【０２３５】
上記のように構成されたインクジェットヘッド２０１においても、上記実施形態３と同様に、アクチュエータ部Ｂを構成する圧電体層４１は、その結晶配向性が（００１）面に揃ったものであり、圧電変位特性も大きな値でかつ揃っていることから、大きな圧電変位（変位量）を得ることが可能で、しかも、複数個のインク吐出素子２０２間において圧電変位特性のばらつきが小さくなる。そして、圧電変位が大きいことから、インクの吐出能力が高く、また、電源電圧の調整幅にマージンを大きくとることができ、複数個のインク吐出素子２０２の個々のインクの吐出ばらつきが小さくなるように、容易にコントロールすることができる。
【０２３６】
ここで、上記の製造方法によって、２５０個の同形状のインク吐出素子２０２を有するインクジェットヘッド２０１を実際に作製し、上記実施形態３と同様に、振動層４３の層厚方向の振動振幅のばらつきを測定したところ、そのばらつきσは１．２％と極めて少ないことが判明した。
【０２３７】
（実施形態５）
図１６は、本発明の実施形態に係るさらに別のインクジェットヘッド２０１におけるインク吐出素子２０２のアクチュエータ部Ｂを示す。この実施形態では、積層膜を形成するために用いた基板（この実施形態では、圧力室基板７０という（次の実施形態６においても同じ））をエッチングして圧力室用開口部７１を形成することで上記実施形態３及び４と同様の圧力室部材とし、これにより、圧力室基板７０（圧力室部材）とアクチュエータ部Ｂとを一体化する点が上記実施形態３及び４とは異なる。
【０２３８】
上記圧力室基板７０とアクチュエータ部Ｂとを一体化したものに、上記実施形態３及び４と同様のインク流路部材とノズル板とを接着することで、図１１と類似の形状のインク吐出素子２０２が得られることになる。
【０２３９】
すなわち、この実施形態では、圧力室用開口部７１が形成された圧力室基板７０の上に、非晶質の酸化アルミニウムからなる膜厚２．５０μｍの振動層６５が設けられ、この振動層６５上に、コバルトを含むイリジウム膜（膜厚０．１０μｍ）からなる第１の電極層６１（共通電極）が設けられ、この第１の電極層６１上に、ＰＺＴ薄膜（膜厚２．５０μｍ）からなる圧電体層６２が設けられ、この圧電体層６２上に、白金薄膜（膜厚０．１０μｍ）からなりかつ上記実施形態３及び４における第１の電極層３３と同様に楕円形状に個別化された第２の電極層６３（個別電極）が設けられている。上記第１の電極層６１、圧電体層６２及び第２の電極層６３は、これらが順に積層されてなる圧電素子を構成することになる。また、振動層６５は、この圧電素子の第１の電極層６１側の面に設けられていることになる。尚、上記振動層６５と第１の電極層６１との間に、該振動層６５と第１の電極層６１との密着性を高める密着層を設けてもよい。この密着層も、チタン、タンタル及びモリブデンの群から選ばれた一種で構成すればよい。
【０２４０】
上記圧電体層６２及び第２の電極層６３は、圧力室基板７０において圧力室用開口部７１が形成された部分（シリコンが取り除かれた空間）の上方位置にのみ、振動層６５及び第１の電極層６１を介して存在するように個別化されており、第１の電極層６１上における上記圧電体層６２及び第２の電極層６３の周囲の部分は、上記実施形態３及び４と同様に、ポリイミド樹脂からなる電気絶縁有機膜６４で被覆されている。また、上記個別化された第２の電極層６３には、金薄膜（膜厚０．１μｍ）の引き出し電極膜７５が設けられている。
【０２４１】
次に、上記インクジェットヘッドの製造方法を図１７により説明する。
【０２４２】
すなわち、図１７（ａ）に示すように、厚さ０．３ｍｍのシリコンからなる圧力室基板７０の表面上に、振動層６５と第１の電極層６１と圧電体層６２と第２の電極層６３とを順次スパッタ法で成膜して積層する。
【０２４３】
上記振動層６５は、ＲＦマグネトロンスパッタ装置を使用して、基板温度４００℃で、酸化アルミニウムのターゲットを用いて、スパッタガスをアルゴンと酸素とが１４：１の混合ガスを用い、ガス圧０．２Ｐａ、スパッタ電力７００Ｗで３時間スパッタリングすることで得られる。また、上記第１の電極層６１、圧電体層６２及び第２の電極層６３は、上記実施形態１で説明した方法と同様にして得られる。
【０２４４】
続いて、図１７（ｂ）に示すように、上記圧力室基板７０において上記各層からなる積層膜の形成面とは反対側の表面に、圧力室開口部７１（大きさ：短軸が２００μｍ、長軸が４００μｍの楕円形状）を形成するためにそれ以外の部分を覆うようにフォトレジスト樹脂膜６６をパターン塗布する。
【０２４５】
そして、図１７（ｃ）に示すように、プラズマ反応エッチング装置を使用して、ＳＦ６ガスを用いてドライエッチングを行い、圧力室基板７０に圧力室開口部７１を形成する。
【０２４６】
次いで、図１７（ｄ）に示すように、上記フォトレジスト樹脂膜６６を除去し、その後、図１７（ｅ）に示すように、上記第２の電極層６３上（圧力室開口部７１の真上の部分）に、楕円形状パターン（大きさ：短軸１８０μｍ、長軸３８０μｍの楕円形状）にフォトレジスト樹脂膜６７を形成する。
【０２４７】
次に、図１７（ｆ）に示すように、平行平板型プラズマ反応エッチング装置を使用し、アルゴンガスとＣＦ４ガスとの混合ガスを用いてドライエッチングして、上記フォトレジスト樹脂膜６７と同形状の楕円パターンに個別化された、圧電体層６２と第２の電極層６３との積層膜を得る。このドライエッチングの際に、第１の電極層６１は、他の層と異なりエッチング速度が遅いので、エッチングの終点として使用できる。
【０２４８】
続いて、図１７（ｇ）に示すように、上記楕円形状のフォトレジスト樹脂膜６７を取り除くとともに、上記個別化された積層膜の周囲に印刷法でポリイミド樹脂の塗膜を形成し、その後にその塗膜を１８０℃で硬化させて、ポリイミド樹脂からなる電気絶縁有機膜６４を形成する。
【０２４９】
次いで、図１７（ｈ）に示すように、上記電気絶縁有機膜６４に、上記第２の電極層６３の一部と重なるように、スパッタ法で金薄膜（膜厚０．１μｍ）からなる引き出し電極７５を形成し、このことで、圧力室基板７０が一体化したアクチュエータ部Ｂが完成する。
【０２５０】
そして、上記圧力室基板７０（圧力室部材）に、上記実施形態３及び４と同様にして、インク流路部品とノズル板とを接着し、こうしてインクジェットヘッド２０１が完成する。
【０２５１】
この実施形態においても、上記実施形態３と同様に、圧電体層６２の結晶配向性が（００１）面に揃っており、このことで、大きな圧電変位（変位量）を得ることが可能で、しかも、複数個のインク吐出素子２０２において圧電変位特性のばらつきを小さく抑えることができる。
【０２５２】
尚、上記第１の電極層６１、圧電体層６２及び第２の電極層６３は、上記実施形態１で述べた材料であれば、どれを用いてもよく、振動層６５は、上記実施形態３で述べた材料であれば、どれを用いてもよい。また、これら各層の厚みも、上記実施形態１及び３で述べた範囲であればよい。
【０２５３】
ここで、上記の製造方法によって、１５０個の同形状のインク吐出素子２０２を有するインクジェットヘッド２０１を実際に作製し、上記実施形態３と同様に、振動層６５の層厚方向の振動振幅のばらつきを測定したところ、そのばらつきσは２．０％と極めて少ないことが判明した。
【０２５４】
（実施形態６）
図１８は、本発明の実施形態に係るさらに別のインクジェットヘッド２０１におけるインク吐出素子２０２のアクチュエータ部Ｂを示し（尚、図１６と同じ部分については同じ符号を付してその詳細な説明は省略する）、図１６で示したもの（実施形態５）に対し、上記実施形態２及び４のように、第１の電極層６１と圧電体層６２との間に配向制御層６９を配設したものであり、他の構成は図１６で示したものと同様である。
【０２５５】
すなわち、この実施形態では、圧力室用開口部７１が形成された圧力室基板７０の上に振動層６５が設けられ、この振動層６５上に第１の電極層６１が設けられ、この第１の電極層６１上に配向制御層６９が設けられ、この配向制御層６９上に圧電体層６２が設けられ、この圧電体層６２上に第２の電極層６３が設けられている。上記第１の電極層６１、配向制御層６９、圧電体層６２及び第２の電極層６３は、これらが順に積層されてなる圧電素子を構成することになる。また、振動層６５は、この圧電素子の第１の電極層６１側の面に設けられていることになる。尚、上記振動層６５と第１の電極層６１との間に、該振動層６５と第１の電極層６１との密着性を高める密着層を設けてもよい。この密着層も、チタン、タンタル及びモリブデンの群から選ばれた一種で構成すればよい。
【０２５６】
上記配向制御層６９も、圧電体層６２及び第２の電極層６３と同様に、圧力室基板７０において圧力室用開口部７１が形成された部分の上方位置にのみ存在するように個別化されている。
【０２５７】
次に、上記インクジェットヘッドの製造方法を図１９により説明する。
【０２５８】
すなわち、実施形態２（又は５）と同様に、厚さ０．３ｍｍのシリコンからなる圧力室基板７０の表面上に、振動層６５と第１の電極層６１と配向制御層６９と圧電体層６２と第２の電極層６３とを順次スパッタ法で成膜して積層する（図１９（ａ）参照）。
【０２５９】
上記振動層６５は、上記実施形態５で説明した方法と同様にして得られる。また、上記第１の電極層６１、配向制御層６９、圧電体層６２及び第２の電極層６３は、上記実施形態２で説明した方法と同様にして得られる。
【０２６０】
続いて、上記実施形態５と同様に、上記圧力室基板７０において上記各層からなる積層膜の形成面とは反対側の表面に、圧力室開口部７１を形成するためにそれ以外の部分を覆うようにフォトレジスト樹脂膜６６をパターン塗布し（図１９（ｂ）参照）、その後、ドライエッチングを行って、圧力室基板７０に圧力室開口部７１を形成する（図１９（ｃ）参照）。
【０２６１】
そして、上記実施形態５と同様に、上記フォトレジスト樹脂膜６６を除去し（図１９（ｄ）参照）、その後、上記第２の電極層６３上（圧力室開口部７１の真上の部分）に、楕円形状パターンにフォトレジスト樹脂膜６７を形成する（図１９（ｅ）参照）。
【０２６２】
次に、上記実施形態５と同様に、ドライエッチングを行って、上記フォトレジスト樹脂膜６７と同形状の楕円パターンに個別化された、配向制御層６９と圧電体層６２と第２の電極層６３との積層膜を得る（図１９（ｆ）参照）。
【０２６３】
続いて、上記実施形態５と同様に、上記楕円形状のフォトレジスト樹脂膜６７を取り除くとともに、上記個別化された積層膜の周囲にポリイミド樹脂の塗膜を形成し、その後にその塗膜を１８０℃で硬化させて、ポリイミド樹脂からなる電気絶縁有機膜６４を形成し（図１９（ｇ）参照）、次いで、この電気絶縁有機膜６４に引き出し電極７５を形成し（図１９（ｈ）参照）、このことで、圧力室基板７０が一体化したアクチュエータ部Ｂが完成する。
【０２６４】
そして、上記圧力室基板７０（圧力室部材）に、上記実施形態５と同様にして、インク流路部品とノズル板とを接着し、こうしてインクジェットヘッド２０１が完成する。
【０２６５】
この実施形態においても、上記実施形態４と同様に、圧電体層６２の結晶配向性が（００１）面に揃っており、このことで、大きな圧電変位（変位量）を得ることが可能で、しかも、複数個のインク吐出素子２０２において圧電変位特性のばらつきを小さく抑えることができる。
【０２６６】
尚、上記第１の電極層６１、配向制御層６９、圧電体層６２及び第２の電極層６３は、上記実施形態２で述べた材料であれば、どれを用いてもよく、振動層６５は、上記実施形態３で述べた材料であれば、どれを用いてもよい。また、これら各層の厚みも、上記実施形態２及び３で述べた範囲であればよい。
【０２６７】
ここで、上記の製造方法によって、１５０個の同形状のインク吐出素子２０２を有するインクジェットヘッド２０１を実際に作製し、上記実施形態３と同様に、振動層６５の層厚方向の振動振幅のばらつきを測定したところ、そのばらつきσは２．３％と極めて少ないことが判明した。
【０２６８】
（実施形態７）
図２０は、本発明の実施形態に係るインクジェット式記録装置８１を示し、このインクジェット式記録装置８１は、上記実施形態３〜６のいずれか１つと同様のインクジェットヘッド２０１を備えている。このインクジェットヘッド２０１において圧力室（上記実施形態３で説明した圧力室３２）に連通するように設けたノズル孔（上記実施形態３で説明したノズル孔３８）から該圧力室内のインクを記録媒体８２（記録紙等）に吐出させて着弾させることにより、記録を行うように構成されている。
【０２６９】
上記インクジェットヘッド２０１は、主走査方向ｘに延びるキャリッジ軸８３に設けられたキャリッジ８４に搭載されていて、このキャリッジ８４がキャリッジ軸８３に沿って往復動するのに応じて主走査方向ｘに往復動するように構成されている。このことで、キャリッジ８３は、インクジェットヘッド２０１と記録媒体８２とを主走査方向ｘに相対移動させる相対移動手段を構成することになる。
【０２７０】
また、このインクジェット式記録装置８１は、上記記録媒体８２をインクジェットヘッド２０１の主走査方向ｘ（幅方向）と略垂直方向の副走査方向ｙに移動させる複数のローラ８５を備えている。このことで、複数のローラ８５は、インクジェットヘッド２０１と記録媒体８２とを副走査方向ｙに相対移動させる相対移動手段を構成することになる。尚、図２０中、ｚは上下方向である。
【０２７１】
そして、インクジェットヘッド２０１がキャリッジ８４により主走査方向ｘに移動しているときに、インクジェットヘッド２０１のノズル孔からインクを記録媒体８２に吐出させ、この一走査の記録が終了すると、上記ローラ８５により記録媒体８２を所定量移動させて次の一走査の記録を行う。
【０２７２】
以上のように、インクジェット式記録装置８１を、複数個のインク吐出素子２０２間のインクの吐出ばらつきを容易にコントロールすることが可能な上記実施形態３〜６のいずれか１つのインクジェットヘッド２０１を用いて構成することにより、紙等の記録媒体８２に対する記録のばらつきを小さくすることができるので、信頼性の向上化を図ることができる。
【０２７３】
（実施形態８）
図２１及び図２２は、本発明の実施形態に係る角速度センサを示し、この角速度センサは、音叉型のものであって、車両に搭載されるナビゲーション装置等に好適に用いられるものである。
【０２７４】
上記角速度センサは、厚み０．３ｍｍのシリコンウエハからなる基板５００を備えている（ガラス基板や金属基板、セラミックス基板であってもよい）。この基板５００は、固定部５００ａと、該固定部５００ａから所定の方向（検出する角速度の回転中心軸が延びる方向；本実施形態では、図２１に示すｙ方向）に延びる一対の振動部５００ｂとを有している。これら固定部５００ａ及び一対の振動部５００ｂは、基板５００の厚み方向（図２１に示すｚ方向）から見て音叉状をなしており、一対の振動部５００ｂは音叉のアーム部に相当していて、振動部５００ｂの幅方向に並んだ状態で互いに平行に延びている。
【０２７５】
上記基板５００の各振動部５００ｂ及び固定部５００ａの振動部側の部分上には、第１の電極層５０３と配向制御層５０４と圧電体層５０５と第２の電極層５０６とが順に積層されている。尚、この角速度センサにおいても、上記基板５００と第１の電極層５０３との間に、上記実施形態２の変形例における圧電素子と同様に、密着層を設けることが好ましい。
【０２７６】
上記第１の電極層５０３、配向制御層５０４、圧電体層５０５及び第２の電極層５０６の各構成材料及び厚みは、上記実施形態２で説明した第１の電極層２、配向制御層１１、圧電体層３及び第２の電極層４とそれぞれ同様である。また、配向制御層５０４及び圧電体層５０５の構造も、配向制御層１５及び圧電体層１６とそれぞれ同様であり、配向制御層５０４における第１の電極層５０３側の表面近傍部は、（１００）面又は（００１）面配向の領域が第１の電極層５０３における配向制御層５０４側の表面部に位置する金属（コバルト等）上に存在していて層厚方向と垂直な断面における上記領域の面積が第１の電極層５０３側から圧電体層５０５側に向かって大きくなる構造を有している。
【０２７７】
上記第２の電極層５０６は、上記各振動部５００ｂ上において、当該振動部５００ｂを振動部５００ｂの幅方向（図２１に示すｘ方向）に振動させるための２つの駆動電極５０７と、当該振動部５００ｂの厚み方向（ｚ方向）の変形（たわみ）を検出するための１つの検出電極５０８とにパターン化されている。
【０２７８】
上記２つの駆動電極５０７は、当該振動部５００ｂの幅方向（ｘ方向）両端部上において、振動部５００ｂの長さ方向（ｙ方向）全体に亘って設けられ、各駆動電極５０７の固定部５００ａ側の端部は、固定部５００ａ上に位置して接続端子５０７ａを構成している。尚、各振動部５００ｂの幅方向一端部上に１つの駆動電極５０７を設けるだけであってもよい。
【０２７９】
一方、上記検出電極５０８は、当該振動部５００ｂの幅方向中央部上において、振動部５００ｂの長さ方向全体に亘って設けられ、上記駆動電極５０７と同様に、検出電極５０８の固定部５００ａ側の端部は、固定部５００ａ上に位置して接続端子５０８ａを構成している。尚、各振動部５００ｂ上において複数の検出電極５０８を設けてもよい。
【０２８０】
尚、上記第１の電極層５０３は、固定部５００ａ上における一対の振動部５００ｂ間の中央位置において、振動部５００ｂとは反対側に突出する接続端子５０３ａを有している。
【０２８１】
上記各振動部５００ｂ上における上記第１の電極層５０３と２つの駆動電極５０７との間には、当該振動部５００ｂがその幅方向に振動するように、振動部５００ｂの固有振動と共振する周波数の電圧が印加されるようになっている。すなわち、第１の電極層５０３には、グランド電圧が印加される一方、２つの駆動電極５０７には、正負が互いに逆の電圧が印加され、このことで、各振動部５００ｂの幅方向一端部側が伸長するときには、他端部側が収縮して、該振動部５００ｂがその他端部側に変形する。一方、各振動部５００ｂの幅方向一端部側が収縮するときには、他端部側が伸長して、振動部５００ｂがその一端部側に変形する。この動作を交互に繰り返すことによって振動部５００ｂがその幅方向に振動する。尚、各振動部５００ｂ上における２つの駆動電極５００ｂのいずれか一方に電圧を印加するだけでも、当該振動部５００ｂをその幅方向に振動させることは可能である。そして、一対の振動部５００ｂは、各振動部５００ｂの幅方向において互いに反対向きに変形し、一対の振動部５００ｂ間の中央にあって該振動部５００ｂの長さ方向に延びる中央線Ｌに対して対称に振動するようになっている。
【０２８２】
上記構成の角速度センサにおいて、一対の振動部５００ｂをその幅方向（ｘ方向）に上記中央線Ｌに対して対称に振動させているときに、その中央線Ｌ回りに角速度ωが加わると、２つ振動部５００ｂは、コリオリ力によって厚み方向（ｚ方向）にたわんで変形し（一対の振動部５００ｂは互いに反対向きに同じ量たわむ）、これにより、圧電体層５０５にもたわみが発生して、第１の電極層５０３と検出電極５０８との間には、コリオリ力の大きさに応じた電圧が発生する。この電圧の大きさ（コリオリ力）から角速度ωを検出することができる。
【０２８３】
すなわち、コリオリ力Ｆｃは、各振動部５００ｂの幅方向の速度をｖ、各振動部５００ｂの質量をｍとすると、
Ｆｃ＝２ｍｖω
となるので、コリオリ力Ｆｃから角速度ωの値が分かることになる。
【０２８４】
次に、上記角速度センサの製造方法について図２３及び図２４に基づいて説明する。
【０２８５】
すなわち、図２３（ａ）に示すように、厚み０．３ｍｍのφ４インチシリコンウエハ（平面図は図２４参照）からなる基板５００を用意し、図２３（ｂ）に示すように、この基板５００上に、上記実施形態２と同様の条件で、第１の電極層５０３をスパッタ法により形成する。
【０２８６】
続いて、図２３（ｃ）に示すように、上記第１の電極層５０３上に、上記実施形態２と同様の条件で、配向制御層５０４をスパッタ法により形成する。上記実施形態２で説明したように、この配向制御層５０４における第１の電極層５０３側の表面近傍は、（１００）面又は（００１）面配向の領域がチタン上に存在しかつ層厚方向と垂直な断面における上記領域の面積が第１の電極層５０３側から上側に向かって大きくなる。
【０２８７】
次いで、図２３（ｄ）に示すように、上記配向制御層５０４上に、上記実施形態２と同様の条件で、圧電体層５０５をスパッタ法により形成する。上記実施形態２で説明したように、この圧電体層５０５は菱面体晶系であり、（００１）面配向度が９０％以上となる。
【０２８８】
続いて、図２３（ｅ）に示すように、上記圧電体層５０５上に、上記実施形態２と同様の条件で、第２の電極層５０６をスパッタ法により形成する。
【０２８９】
次いで、図２３（ｆ）及び図２４に示すように、上記第２の電極層５０６をパタ−ニングして駆動電極５０７及び検出電極５０８を形成する。すなわち、第２の電極層５０６上に感光樹脂を塗布し、この感光樹脂に駆動電極５０７及び検出電極５０８のパタ−ンを露光し、その後、露光していない部分の感光樹脂を除去し、この感光樹脂を除去した部分における第２の電極層５０６をエッチングにより除去し、次いで、駆動電極５０７及び検出電極５０８上の感光樹脂を除去する。
【０２９０】
上記第２の電極層５０６のパターンニング後、同様の工程により圧電体層５０５、配向制御層５０４及び第１の電極層５０３をパタ−ニングするとともに、上記基板５００をパタ−ニングして固定部５００ａ及び振動部５００ｂを形成する。こうして上記の角速度センサが完成する。
【０２９１】
尚、上記各層の成膜法はスパッタ法に限らず、熱処理による結晶化工程なしに直接に結晶性薄膜を形成する成膜法（例えばＣＶＤ法等）であればよい。
【０２９２】
ここで、図２５及び図２６を参照しながら従来の角速度センサについて説明する。
【０２９３】
この従来の角速度センサは、厚み０．３ｍｍの水晶からなる圧電体６００を備え、この圧電体６００が、本実施形態に係る角速度センサの基板５００と同様に、固定部６００ａと該固定部６００ａからその一側方（図２５に示すｙ方向）に互いに平行に延びる一対の振動部６００ｂとを有している。そして、上記各振動部６００ｂの厚み方向（図２５に示すｚ方向）に対向する両面には、当該振動部６００ｂをその幅方向（図２５に示すｘ方向）に振動させるための駆動電極６０３がそれぞれ１つずつ設けられ、各振動部６００ｂの両側面には、当該振動部６００ｂの厚み方向の変形を検出するための検出電極６０７がそれぞれ１つずつ設けられている。
【０２９４】
そして、上記従来の角速度センサにおいて、各振動部６００ｂにおける２つの駆動電極６０３間に、当該振動部６００ｂの固有振動と共振する周波数の電圧を印加して、本実施形態に係る角速度センサと同様に、一対の振動部６００ｂをその幅方向（ｘ方向）に該一対の振動部６００ｂ間の中央にある中央線Ｌに対して対称に振動させる。このときに、その中央線Ｌ回りに角速度ωが加わると、一対の振動部６００ｂは、コリオリ力によって厚み方向（ｚ方向）にたわんで変形し、各振動部６００ｂにおける２つの検出電極６０７間にコリオリ力の大きさに応じた電圧が発生し、この電圧の大きさ（コリオリ力）から角速度ωを検出することができる。
【０２９５】
上記従来の角速度センサにおいては、水晶からなる圧電体６００を用いるので、その圧電定数は−３ｐＣ／Ｎとかなり低く、しかも固定部６００ａ及び振動部６００ｂは機械加工により形成するため、小型化が困難であり、寸法精度が低いという問題がある。
【０２９６】
これに対し、本実施形態に係る角速度センサにおいては、角速度を検出する部分（振動部５００ｂ）が、上記実施形態２と同様の構成の圧電素子で構成されていることになるので、上記従来の角速度センサに対して圧電定数を４０倍程度に大きくすることができ、かなりの小型化を図ることができる。また、薄膜形成技術を用いて微細加工を行うことができ、寸法精度を格段に向上させることができる。さらに、工業的に量産しても、特性の再現性が良好で、ばらつきが少なく、耐電圧及び信頼性に優れる。
【０２９７】
尚、本実施形態における角速度センサにおいても、第１の電極層５０３、配向制御層５０４、圧電体層５０５及び第２の電極層５０６の材料は、上記実施形態２で述べた材料であれば、どれを用いてもよい。そして、上記実施形態１のように、この配向制御層５０４をなくすようにしても、高性能の角速度センサが得られる。
【０２９８】
また、本実施形態における角速度センサにおいては、基板５００に一対の振動部５００ｂを１組しか設けていないが、複数組設けて、種々の方向に延びる複数軸回りの角速度を検出するようにしてもよい。
【０２９９】
さらに、本実施形態における角速度センサにおいては、基板５００の各振動部５００ｂ及び固定部５００ａの振動部側の部分上に、第１の電極層５０３と配向制御層５０４と圧電体層５０５と第２の電極層５０６とを順に積層したが、これら各層を積層する箇所は、各振動部５００ｂ上のみであってもよい。
【０３００】
加えて、上記実施形態では、本発明の圧電素子を、インクジェットヘッド（インクジェット式記録装置）及び角速度センサに適用したが、この以外にも、薄膜コンデンサー、不揮発性メモリ素子の電荷蓄積キャパシタ、各種アクチュエータ、赤外センサー、超音波センサー、圧力センサー、加速度センサー、流量センサー、ショックセンサー、圧電トランス、圧電点火素子、圧電スピーカー、圧電マイクロフォン、圧電フィルタ、圧電ピックアップ、音叉発振子、遅延線等にも適用可能である。特に、ディスク装置（コンピュータの記憶装置等として用いられるもの）における回転駆動されるディスクに対して情報の記録又は再生を行うヘッドが基板上に設けられたヘッド支持機構において、該基板上に設けた薄膜圧電体素子によって、基板を変形させて該ヘッドを変位させるディスク装置用薄膜圧電体アクチュエータ（例えば特開２００１−３３２０４１号公報参照）に好適である。つまり、上記薄膜圧電体素子は、上記実施形態で説明したものと同様の構成の第１の電極層と配向制御層と圧電体層と第２の電極層とが順に積層されてなり、この第２の電極層が上記基板に接合されたものである。
【０３０１】
【発明の効果】
以上説明したように、本発明によると、基板上に、コバルト、ニッケル、鉄、マンガン及び銅の群から選ばれた少なくとも１種の金属と貴金属との合金からなる、結晶配向制御層を兼ねる第１の電極層を設け、この第１の電極層におけるコバルト、ニッケル、鉄、マンガン及び銅の群から選ばれた少なくとも１種の金属の含有量を、０を越え２６モル％以下とし、この第１の電極層上に、菱面体晶系又は正方晶系のペロブスカイト型酸化物からなる圧電体層を設けた構成とすることによって、成膜後の熱処理による結晶化工程なしに直接的に、例えばスパッタ法等で、結晶構造と優先配向面とを制御した圧電体層を形成することでき、このことで、ゾルゲル法のように、クラックの発生や特性ばらつきの要因となるような熱処理による結晶化工程を無くすことができる。この結果、工業的に量産しても圧電特性の再現性、ばらつき及び信頼性の良好な圧電素子とこの圧電素子を有するインクジエツトヘツド及び角速度センサとを提供することができる。また、吐出能のばらつきが少なくて高い信頼性を有するインクジエツト式記録装置を提供することができる。
【図面の簡単な説明】
【図１】 本発明の実施形態に係る圧電素子を示す斜視図である。
【図２】 図１の圧電素子の製造方法を示す工程図である。
【図３】 図１の圧電素子において第１の電極層と第２の電極層との間に三角波電圧を印加したときの、圧電素子の先端の変位量を示す特性図である。
【図４】 比較例１の圧電素子における図３相当図である。
【図５】 本発明の実施形態に係る他の圧電素子を示す斜視図である。
【図６】 図５の圧電素子の製造方法を示す工程図である。
【図７】 図５の圧電素子の変形例を示す斜視図である。
【図８】 図７の圧電素子の製造方法を示す工程図である。
【図９】 図５の圧電素子における図３相当図である。
【図１０】 本発明の実施形態に係るインクジェットヘッドを示す概略図である。
【図１１】 図１０のインクジェットヘッドのインク吐出素子を示す一部破断した分解斜視図である。
【図１２】 図１１のXII−XII線断面図である。
【図１３】 図１０のインクジェットヘッドの製造方法を示す工程図である。
【図１４】 本発明の実施形態に係る他のインクジェットヘッドの要部（アクチュエータ部）を示す図１２相当図である。
【図１５】 図１４のインクジェットヘッドの製造方法を示す工程図である。
【図１６】 本発明の実施形態に係るさらに別のインクジェットヘッドの要部（アクチュエータ部）を示す図１２相当図である。
【図１７】 図１６のインクジェットヘッドの製造方法を示す工程図である。
【図１８】 本発明の実施形態に係るさらに別のインクジェットヘッドの要部（アクチュエータ部）を示す図１２相当図である。
【図１９】 図１８のインクジェットヘッドの製造方法を示す工程図である。
【図２０】 本発明の実施形態に係るインクジェット式記録装置を示す概略斜視図である。
【図２１】 本発明の実施形態に係る角速度センサを示す概略斜視図である。
【図２２】 図２１のXXII−XXII線断面図である。
【図２３】 図２１の角速度センサの製造方法を示す工程図である。
【図２４】 図２１の角速度センサの製造方法において、第２の電極層をパターニングした状態を示す平面図である。
【図２５】 水晶を用いた従来の角速度センサを示す概略斜視図である。
【図２６】 図２５のXXVI−XXVI線断面図である。
【符号の説明】
１ 基板
２ 第１の電極層
３ 圧電体層
４ 第２の電極層
１１ 配向制御層
１４ 密着層
２０ 圧電素子
３２ 圧力室
３３ 第１の電極層（個別電極）
３８ ノズル孔
４１ 圧電体層
４２ 第２の電極層（共通電極）
４３ 振動層
４６ 配向制御層
５１ 基板
６１ 第１の電極層（共通電極）
６２ 圧電体層
６３ 第２の電極層（個別電極）
６５ 振動層
６９ 配向制御層
７０ 圧力室基板（圧力室部材）
８１ インクジェット式記録装置
８２ 記録媒体
８４ キャリッジ（相対移動手段）
２０１ インクジエツトヘツド
５００ 基板
５００ａ 固定部
５００ｂ 振動部
５０３ 第１の電極層
５０４ 配向制御層
５０５ 圧電体層
５０６ 第２の電極層
５０７ 駆動電極
５０８ 検出電極
Ａ 圧力室部材
Ｂ アクチュエータ部[0001]
BACKGROUND OF THE INVENTION
  The present invention belongs to a technical field relating to a piezoelectric element exhibiting an electromechanical conversion function, an inkjet head using the piezoelectric element, an angular velocity sensor, a manufacturing method thereof, and an inkjet recording apparatus including the inkjet head as a printing unit.
[0002]
[Prior art]
  In general, a piezoelectric material is a material that converts mechanical energy into electrical energy or converts electrical energy into mechanical energy. A typical example of this piezoelectric material is lead zirconate titanate (Pb (Zr, Ti) O) having a perovskite crystal structure.₃(Hereinafter referred to as PZT). The direction in which the largest piezoelectric displacement is obtained in this PZT is the <001> axis direction (c-axis direction) in the case of tetragonal system, and the <111> axis direction in the case of rhombohedral system. However, since many piezoelectric materials are polycrystals composed of aggregates of crystal grains, the crystal axes of the crystal grains are in random directions. Therefore, the spontaneous polarization Ps is also randomly arranged.
[0003]
  By the way, with the recent miniaturization of electronic devices, there is a strong demand for miniaturization of piezoelectric elements using piezoelectric materials. In order to satisfy this requirement, the piezoelectric element tends to be used in the form of a thin film whose volume can be remarkably reduced as compared with a sintered body that has been used for many applications. Research and development for thinning the film has become popular. For example, in the case of tetragonal PZT, the spontaneous polarization Ps is oriented in the <001> axis direction. Therefore, in order to realize high piezoelectric characteristics even if the film is thinned, the <001> axis of the crystal constituting the PZT thin film is used. It is necessary to align in the direction perpendicular to the substrate surface. In order to realize this, conventionally, a single crystal substrate made of magnesium oxide (MgO) having a NaCl type crystal structure cut out so that the crystal orientation (100) plane is exposed on the surface is used. A Pt electrode thin film oriented in the (100) plane is formed as a lower electrode, and a PZT thin film with good crystallinity is oriented on the Pt electrode in the direction perpendicular to the surface in the <001> axis. It was formed at a temperature of ° C. (see, for example, Non-Patent Document 1 and Patent Document 1).
[0004]
  The above method is characterized by using a substrate made of MgO single crystal, and for the first time, a piezoelectric thin film preferentially crystallized in a crystal direction having high piezoelectric properties was realized. Is a very expensive material, there is a problem in terms of cost in mass production of industrial products using a piezoelectric element having a piezoelectric thin film formed by this method.
[0005]
  Therefore, various ideas have been made as a method of forming a crystal orientation film of a piezoelectric material on an inexpensive substrate such as silicon. For example, as a method for controlling the preferential orientation plane of a crystal of a piezoelectric layer such as PZT, Patent Document 2 discloses that a base layer mainly composed of zirconium oxide is formed on the surface of a substrate, and iridium is formed on the base layer. A lower electrode containing is formed, an ultrathin titanium layer is laminated on the lower electrode, and an amorphous material containing a metal element and an oxygen element, which constitutes a ferroelectric material that exhibits piezoelectric characteristics, is formed on the titanium layer. A manufacturing method (sol-gel method) is disclosed in which a piezoelectric precursor thin film is formed, and the amorphous thin film is crystallized by a method of heat-treating at a high temperature to change into a piezoelectric thin film that exhibits piezoelectricity. It is shown that the crystal orientation of the piezoelectric thin film can be controlled by controlling the thickness of the titanium layer at that time.
[0006]
[Patent Document 1]
        JP-A-10-209517
[0007]
[Patent Document 2]
        JP 2001-88294 A
[0008]
[Non-Patent Document 1]
        “Journal of Applied Physics
        (Journal of Applied Physics) ”, (USA), American Physical Society,
        February 15, 1989, Volume 65, No. 4, p.1666-1670
[0009]
[Problems to be solved by the invention]
  However, although the method disclosed in Patent Document 2 is excellent as a method not using an expensive MgO single crystal substrate, a piezoelectric thin film is formed by a sol-gel method. As in the case of forming a thin film, it is difficult to obtain a film with good crystallinity that is crystallized during film formation. For this purpose, an amorphous piezoelectric precursor thin film is once formed, and the laminated film including this film is finally heat treated together with the substrate so that the crystal axes are preferentially oriented in an appropriate direction.
[0010]
  For this reason, in the sol-gel method, when a piezoelectric element is industrially mass-produced, cracks are likely to occur in the amorphous piezoelectric precursor thin film due to volume changes in the degreasing process for removing organic substances. Even in the step of crystallizing the precursor thin film by heating at a high temperature, cracks and film peeling from the lower electrode are likely to occur due to crystal change, and since there is a post-heat treatment step after film formation, the number of steps increases, However, there is a problem that the yield is lowered.
[0011]
  On the other hand, in Patent Document 2, a method other than the sol-gel method (including the MOD method) is a method in which an amorphous thin film is once formed and then synthesized by changing to a crystalline thin film by a post-treatment that is a crystallization heat treatment. In other words, an attempt was made to control the orientation of a representative PZT film of a ferroelectric thin film by a film forming method such as sputtering, laser ablation, or CVD, which directly forms a crystalline thin film without a crystallization process by heat treatment.・ It is said that the orientation control could not be performed except for the gel method. The reason is that crystallization of the PZT film gradually proceeds from the lower electrode side to the upper electrode side in the sol-gel method, whereas the crystallization of the PZT film proceeds at random in the CVD method or the sputtering method. This is because the lack of regularity in crystallization makes orientation control difficult.
[0012]
  The present invention has been made in view of this point, and an object of the present invention is to obtain a highly reliable piezoelectric element that is low in cost and excellent in piezoelectric characteristics.
[0013]
[Means for Solving the Problems]
  In order to achieve the above object, in the present invention, the electrode layer is made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal.The content of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper in the electrode layer is more than 0 and not more than 26 mol%On the electrode layer, a piezoelectric layer made of rhombohedral or tetragonal perovskite oxide was formed, and the piezoelectric layer was preferentially oriented in the (001) plane.
[0014]
  Specifically, in the invention of claim 1, the first electrode layer, the piezoelectric layer provided on the first electrode layer, and the second electrode layer provided on the piezoelectric layer, The piezoelectric element provided with
[0015]
  The first electrode layer is made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal,The content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and not more than 26 mol%;The piezoelectric layer is made of a perovskite oxide preferentially oriented in a rhombohedral or tetragonal (001) plane.
[0016]
  With the above configuration, when the piezoelectric layer is formed on the first electrode layer by sputtering or the like, the first electrode layer is in crystal orientation even if the first electrode layer has (111) plane orientation or the like. Playing the role of the control layer, the piezoelectric layer has the (001) plane (in the case of rhombohedral system, the (100) plane and the (001) plane are the same, so this rhombohedral (100) plane) Orientation). That is, the first electrode layer that is the direct base of the piezoelectric layer is composed of metal atoms that are relatively easy to chemisorb oxygen such as cobalt, nickel, iron, manganese, and copper, and noble metal atoms that are not easily oxidized (for example, platinum atoms). Therefore, the surface of the first electrode layer is assumed to be a smooth surface in which the metal atoms are scattered in the noble metal atoms. When a piezoelectric layer made of a perovskite-type crystal structure oxide such as PZT (preferably an element containing lead in excess of the stoichiometric composition) is formed on the first electrode layer by, for example, sputtering. In order to stabilize the oxygen content of the oxide, oxygen is mixed with an inert argon gas as a sputtering gas. The oxygen gas atoms are first scattered on the smooth surface of the first electrode film. To be adsorbed on metal atoms such as cobalt. This adsorption takes place by taking a stable coordination structure with an NaCl type crystal structure, and an oxide having a perovskite type crystal structure having a relationship between a metal atom (for example, lead) and an oxygen atom of the same coordination is connected to it. Crystal growth will occur. At this time, since the oxygen partial pressure at the time of film formation is relatively low and the amount of oxygen in the film formation atmosphere is small, a phenomenon in which only oxygen atoms are arranged in layers (the (111) plane grows at this time) hardly occurs. It is considered that (001) planes in which metal atoms and oxygen atoms are alternately arranged in layers are easy to grow. Of course, a piezoelectric film also grows on the noble metal atom, but here, a piezoelectric film of an aggregate of particles with random crystal planes grows (including (001) -oriented crystal grains in this case) To do). When a substrate such as silicon is used, since the first electrode layer is normally (111) -oriented, the metal atoms such as cobalt in the surface portion of the first electrode layer in the piezoelectric layer are used. In the upper region of the portion where no exists, it becomes a plane orientation other than the (001) plane (for example, (111) plane orientation) or becomes amorphous. However, since the (001) plane easily grows in the film-forming atmosphere containing oxygen as described above, the crystal growth rate of the (001) plane of the piezoelectric film formed on the metal atom is high, and the shape is an inverted cone. Since film growth occurs in a state where the growth of crystal grains (for example, (111) -oriented grains) oriented to a plane with a slow crystal growth rate other than the (001) plane is suppressed while spreading horizontally, the whole finally A (001) plane oriented piezoelectric film is considered. That is, the area of the (001) plane orientation region in the cross section perpendicular to the layer thickness direction of the piezoelectric layer increases from the first electrode layer side toward the opposite side (second electrode layer side), At the stage where the thickness of the layer reaches about 20 nm, almost the entire surface becomes a (001) -oriented region. As a result, when the thickness of the piezoelectric layer is, for example, 0.5 μm or more, most of the piezoelectric layer becomes a region of (001) plane orientation, and a (001) plane orientation degree of 90% or more is sufficiently obtained. .
[0017]
  The crystal orientation of the piezoelectric layer can be controlled in this way because the piezoelectric material is a substance having a perovskite crystal structure, and the arrangement of metal atoms such as lead and oxygen atoms and the spacing of the crystal lattice are cobalt, nickel. This is because it is almost the same as the oxide of rock salt (NaCl) structure, which is a stable substance formed by oxidation of easily oxidizable metals such as iron, manganese, and copper. The crystal orientation of the piezoelectric layer can be controlled by using a method of forming a thin film of the type in which the film is grown.
[0018]
  Therefore, since the first electrode layer plays a role of controlling the crystal orientation of the piezoelectric layer in addition to the role as an electrode, a crystal formed by heat treatment other than the sol-gel method on an inexpensive substrate such as silicon. Even if it is a film-forming method (sputtering method, CVD method, etc.) that directly forms a crystalline thin film without a forming step, a piezoelectric layer with good orientation can be obtained. This eliminates the step of crystallizing the piezoelectric layer by heat treatment after film formation. As a result, the generation of cracks and variations in characteristics can be reduced, and the reproducibility and variations in piezoelectric characteristics can be achieved even in industrial mass production. In addition, a highly reliable piezoelectric element can be obtained. Since this piezoelectric element is used by applying an electric field in a direction perpendicular to the film surface of the piezoelectric layer, particularly in a tetragonal perovskite PZT film, the electric field direction is <001 due to the (001) plane orientation. > Large piezoelectric characteristics can be obtained in parallel with the polarization axis direction. In addition, since polarization does not rotate due to application of an electric field, variations in piezoelectric characteristics can be suppressed and reliability can be improved. On the other hand, in the rhombohedral perovskite type PZT film, the polarization axis is the <111> direction, so that an angle of about 54 ° occurs between the electric field direction and the polarization axis direction due to the (100) plane orientation. By improving the (100) plane orientation, the polarization can always maintain a constant angle with respect to the applied electric field. In this case as well, the polarization does not rotate due to the applied electric field, thereby causing variations in piezoelectric characteristics. Can be suppressed and reliability can be improved (for example, in the case of a non-oriented PZT film, the polarization is directed in various directions. Therefore, when an electric field is applied, the polarization is parallel to the electric field. (Because the axis is directed, the piezoelectric characteristics have voltage dependency and the variation becomes large, or the change with time occurs, which causes a problem in reliability).
[0019]
  In addition, since a piezoelectric layer having good crystal orientation can be easily obtained without using an expensive MgO single crystal substrate, by using an inexpensive glass substrate, metal substrate, ceramic substrate, Si substrate, etc. Manufacturing cost can be reduced.
[0020]
  Furthermore, even if the thickness of the piezoelectric layer is 1 μm or more, the same process needs to be repeated many times in order to form a thick film as in the sol-gel method in which a thick film cannot be formed by a single coating process. Therefore, the piezoelectric layer can be easily formed by a sputtering method or the like, and a decrease in yield can be suppressed.
[0021]
  Here, if the content of the metal exceeds 26 mol%, the crystallinity and orientation of the piezoelectric layer deteriorate, so the content is set to 26 mol% or less.
[0022]
  Claim2In the invention of claim1In the invention, the first electrode layer is provided on the substrate, and an adhesion layer for improving adhesion between the substrate and the first electrode layer is provided between the substrate and the first electrode layer. IsThe substrate is made of any one of a silicon substrate, a glass substrate, a metal substrate, and a ceramic substrate.Shall.
[0023]
  By doing so, it is possible to improve the adhesion between the substrate and the first electrode layer, to prevent film peeling at the time of manufacturing the piezoelectric element, and to connect between the first and second electrode layers. Even when the operation is performed by applying a voltage, film peeling hardly occurs.In addition, the manufacturing cost can be reduced by using an inexpensive substrate.
[0024]
  Claim3In the invention of claim2In the invention, the adhesion layer is made of one kind selected from the group consisting of titanium, tantalum and molybdenum.
[0025]
  Thus, a material suitable for improving the adhesion between the substrate and the first electrode layer can be obtained.
[0026]
  Claim4In the invention of claim 1,Any one of ~ 3In the invention, an orientation control layer comprising a perovskite oxide preferentially oriented in a cubic or tetragonal (100) plane or (001) plane is provided between the first electrode layer and the piezoelectric layer. It is assumed that
[0027]
  Thus, if the orientation control layer is formed on the first electrode layer by sputtering or the like, even if the first electrode layer has (111) plane orientation or the like, the piezoelectric layer of the invention of claim 1 Similarly, the orientation control layer is easily oriented to the (100) plane or the (001) plane (in the case of a cubic system, the (100) plane and the (001) plane are the same). When a piezoelectric layer having the same crystal structure as that of the orientation control layer is formed on the orientation control layer thus formed, the orientation control layer causes the piezoelectric layer to have (001) plane orientation. By providing such an orientation control layer, it is possible to use a material that can further improve crystallinity and orientation for the orientation control layer while using a piezoelectric material with good piezoelectric characteristics for the piezoelectric layer. As a result, a piezoelectric layer having high crystal orientation and stability can be easily obtained. In the orientation control layer, the region that is not oriented in the (100) plane or the (001) plane may exist not only in the vicinity of the surface of the first electrode layer but also on the surface on the piezoelectric layer side. Even in such a case, if the layer thickness of the orientation control layer is 0.01 μm or more, most of the surface on the piezoelectric layer side becomes a (100) plane or (001) plane oriented region, and the piezoelectric body The (001) plane orientation degree of the layer can be 90% or more.
[0028]
  In addition, by providing such an orientation control layer, a crystalline thin film is directly formed on an inexpensive substrate such as silicon at a temperature that does not reach 600 ° C. without a crystallization step by heat treatment other than the sol-gel method. Even if the film forming method (sputtering method, CVD method, etc.) is performed, a piezoelectric layer with good orientation can be obtained. Thus, the piezoelectric layer is crystallized by heat treatment after film formation as in the sol-gel method. Compared with the case where the process can be eliminated and the orientation control layer is not provided, the film can be formed at a lower temperature, and a piezoelectric element with more excellent reproducibility, variation and reliability of piezoelectric characteristics can be obtained.
[0029]
  Claim5In the invention of claim4In the invention, the orientation control layer is composed of lead lanthanum titanate or lead lanthanum titanate to which at least one of magnesium and manganese is added.
[0030]
  That is, for example, in the sputtering method, lead lanthanum titanate is more stable and easier to form a crystalline film than PZT having particularly good piezoelectric characteristics. Thus, a (100) plane or (001) plane alignment film can be easily formed. When PZT is used for the piezoelectric layer, this lead lanthanum titanate and PZT have the same crystal structure. Therefore, if a piezoelectric layer is formed on the orientation control layer, the surface of the lead lanthanum titanate is formed. PZT having a similar ion arrangement grows as it is, so that it can be easily crystallized in the (001) plane even at a low temperature.
[0031]
  Claim6In the invention of claim4In the invention, the orientation control layer is made of a perovskite oxide containing strontium.
[0032]
  As a result, a perovskite oxide containing strontium can be formed at a lower temperature than PZT or the like, as in the case of lead lanthanum titanate, and a thin film with good orientation and crystallinity can be easily obtained.
[0033]
  Claim7In the invention of claim6In the present invention, the orientation control layer contains strontium titanate.
[0034]
  As a result, the (100) plane or (001) plane orientation and crystallinity of the orientation control layer can be reliably improved, and the orientation of the piezoelectric layer can be improved.
[0035]
  Claim8In the invention of claim 1,7In any one of the inventions, the noble metal in the first electrode layer is at least one selected from the group consisting of platinum, iridium, palladium, and ruthenium.
[0036]
  As a result, the piezoelectric element can sufficiently withstand the temperature at which each film of the piezoelectric element is formed by sputtering or the like, and can be made of a material suitable as an electrode.
[0037]
  Claim9According to the present invention, there is provided a piezoelectric element in which a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially laminated, a vibration layer provided on a surface on the second electrode layer side of the piezoelectric element, A pressure chamber member having a pressure chamber for containing ink and bonded to a surface of the vibration layer opposite to the piezoelectric element, and the vibration layer is formed in a layer thickness direction by a piezoelectric effect of the piezoelectric layer of the piezoelectric element. It is an invention of an ink jet head configured to be displaced and eject ink in the pressure chamber.
[0038]
  In the present invention, the first electrode layer of the piezoelectric element is made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal,The content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and not more than 26 mol%;The piezoelectric layer is made of a perovskite oxide preferentially oriented in a rhombohedral or tetragonal (001) plane.
[0039]
  According to the present invention, the first electrode layer, the piezoelectric layer, the second electrode layer, and the vibration layer are sequentially formed on the substrate by a sputtering method, and the pressure chamber member is joined to the vibration layer, and then the substrate is mounted. If removed, an ink jet head provided with a piezoelectric element having the same structure as that of the first aspect of the invention can be obtained. As a result, the ink ejection capability is increased, and even when a large number of pressure chambers and nozzle holes are provided and piezoelectric elements are provided so as to correspond to the respective pressure chambers (nozzle holes), the space between these piezoelectric elements is increased. Variations are reduced and ink can be stably ejected from any nozzle hole. In addition, since the ink ejection capability is high, a margin can be taken with respect to the adjustment range of the power supply voltage, thereby making it possible to easily control variations in ink ejection.
[0040]
  Claim10In the invention of claim9In the present invention, the orientation control comprising a perovskite oxide preferentially oriented in the cubic or tetragonal (100) plane or (001) plane between the first electrode layer and the piezoelectric layer of the piezoelectric element It is assumed that a layer is provided.
[0041]
  Thus, the first electrode layer, the orientation control layer, the piezoelectric layer, the second electrode layer, and the vibration layer are sequentially formed on the substrate by sputtering or the like, and the pressure chamber member is joined to the vibration layer. If the substrate is removed later, the claim4An ink jet head having a piezoelectric element having the same configuration as that of the present invention can be obtained, and the ink ejecting ability of the ink jet head can be stably increased, and ink ejection variations can be easily controlled.
[0042]
  Claim11In the invention, a piezoelectric element in which a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially laminated, a vibration layer provided on a surface on the first electrode layer side of the piezoelectric element, A pressure chamber member having a pressure chamber for containing ink and bonded to a surface of the vibration layer opposite to the piezoelectric element, and the vibration layer is arranged in a layer thickness direction by a piezoelectric effect of the piezoelectric layer of the piezoelectric element. An inkjet head configured to displace and eject ink in the pressure chamber is an object.
[0043]
  And the 1st electrode layer of the above-mentioned piezoelectric element consists of an alloy of at least one sort of metal chosen from the group of cobalt, nickel, iron, manganese, and copper, and a noble metal,The content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and not more than 26 mol%;The piezoelectric layer is made of a perovskite oxide preferentially oriented in a rhombohedral or tetragonal (001) plane.
[0044]
  Thus, if the pressure chamber member is used as a substrate and the vibration layer, the first electrode layer, the piezoelectric layer, and the second electrode layer are sequentially formed thereon by a sputtering method or the like, it is claimed.9An ink jet head having the same effect as that of the present invention can be obtained.
[0045]
  Claim12In the invention of claim11In the invention, the orientation control comprising a perovskite type oxide preferentially oriented in a cubic or tetragonal (100) plane or (001) plane between the first electrode layer and the piezoelectric layer of the piezoelectric element It is assumed that a layer is provided.
[0046]
  In this way, if the pressure chamber member is used as a substrate, the vibration layer, the first electrode layer, the orientation control layer, the piezoelectric layer, and the second electrode layer are sequentially formed on the substrate by sputtering or the like. , Claims10An ink jet head having the same effect as that of the present invention can be obtained.
[0047]
  Claim13The invention includes a substrate having a fixed portion and at least a pair of vibrating portions extending in a predetermined direction from the fixed portion, and a first electrode layer, a piezoelectric layer, and a first layer are formed on at least each vibrating portion of the substrate. Two electrode layers are sequentially stacked, and the second electrode layer on each vibration part has at least one drive electrode for vibrating the vibration part in the width direction of the vibration part, and the vibration part It is an invention of an angular velocity sensor patterned on at least one detection electrode for detecting deformation in the thickness direction.
[0048]
  In the present invention, the first electrode layer is made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal,The content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and not more than 26 mol%;The piezoelectric layer is made of a perovskite oxide preferentially oriented in a rhombohedral or tetragonal (001) plane.
[0049]
  According to the present invention, by applying a voltage between the drive electrode of the second electrode layer and the first electrode layer, each vibration part of the substrate is vibrated in the width direction of the vibration part. When deformed in the thickness direction, a voltage is generated between the detection electrode of the second electrode layer and the first electrode layer, and the angular velocity can be detected from the magnitude of this voltage (Coriolis force). Since the portion for detecting the angular velocity (vibrating portion) is composed of a piezoelectric element having the same configuration as that of the first aspect of the invention, the piezoelectric constant is higher than that of the conventional angular velocity sensor using quartz. Can be increased to about 40 times, and the size can be considerably reduced. In addition, even if industrially mass-produced, an angular velocity sensor with good reproducibility of characteristics, little variation, and good withstand voltage and reliability can be obtained.
[0050]
  Claim14In the invention of claim13In the invention, an orientation control layer comprising a perovskite oxide preferentially oriented in a cubic or tetragonal (100) plane or (001) plane is provided between the first electrode layer and the piezoelectric layer. It is assumed that
[0051]
  Thus, the part for detecting the angular velocity (vibration part) is claimed.4An angular velocity sensor constituted by a piezoelectric element having the same configuration as that of the present invention is obtained, and the reproducibility, withstand voltage, and reliability of the characteristics of the angular velocity sensor are improved.
[0052]
  Claim15The invention of the present invention is an invention of a method for manufacturing a piezoelectric element. In this invention, an alloy of a noble metal and at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper is formed on a substrate. A step of forming a first electrode layer by sputtering, and a piezoelectric layer made of a perovskite oxide preferentially oriented in a rhombohedral or tetragonal (001) plane on the first electrode layer. And a step of forming a second electrode layer on the piezoelectric layer.Thus, the content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less.Shall.
[0053]
  According to the present invention, the piezoelectric element according to the invention of claim 1 can be easily manufactured.
[0054]
  Claim16In this invention, as a method for manufacturing a piezoelectric element, a first electrode layer made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal is sputtered on a substrate. And an orientation control layer made of a perovskite oxide preferentially oriented in the cubic or tetragonal (100) plane or (001) plane on the first electrode layer by sputtering. Forming a piezoelectric layer made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane on the orientation control layer by sputtering, and the piezoelectric layer. Forming a second electrode layer thereon.Thus, the content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less.Shall.
[0055]
  This makes the claim4The piezoelectric element according to the invention can be easily manufactured.
[0056]
  Claim17The invention includes a piezoelectric element in which a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially laminated, and the vibration layer is displaced in the layer thickness direction by the piezoelectric effect of the piezoelectric layer of the piezoelectric element. It is an invention of a manufacturing method of an ink jet head configured to discharge ink in a pressure chamber.
[0057]
  And in this invention, the process of forming the 1st electrode layer which consists of an alloy of the at least 1 sort (s) of metal chosen from the group of cobalt, nickel, iron, manganese, and copper on a board | substrate by a sputtering method, Forming a piezoelectric layer made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane on the first electrode layer by sputtering, and on the piezoelectric layer Forming a second electrode layer, forming a vibration layer on the second electrode layer, and forming a pressure chamber on a surface of the vibration layer opposite to the second electrode layer. A pressure chamber member for bonding, and a step of removing the substrate after the bonding step.Thus, the content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less.Shall.
[0058]
  According to the invention, the claims9The ink jet head according to the invention can be easily manufactured.
[0059]
  Claim18The invention includes a piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer, and a second electrode layer are sequentially stacked, and the vibration layer is formed by the piezoelectric effect of the piezoelectric layer of the piezoelectric element. The present invention is directed to a method of manufacturing an ink jet head configured to discharge ink in a pressure chamber by being displaced in the thickness direction.
[0060]
  Forming a first electrode layer made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper on the substrate by a sputtering method; A step of forming an orientation control layer made of a perovskite oxide preferentially oriented on a cubic or tetragonal (100) plane or (001) plane on the electrode layer, and on the orientation control layer A step of forming a piezoelectric layer made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane by sputtering, and forming a second electrode layer on the piezoelectric layer. A step of forming a vibration layer on the second electrode layer, and a pressure chamber member for forming a pressure chamber on a surface of the vibration layer opposite to the second electrode layer. And after the joining step, Including a step of removing the serial boardThus, the content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less.Shall.
[0061]
  This makes the claim10The ink jet head according to the invention can be easily manufactured.
[0062]
  Claim19The invention includes a piezoelectric element in which a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially stacked, and the vibration layer is displaced in the layer thickness direction by the piezoelectric effect of the piezoelectric layer of the piezoelectric element. The present invention is directed to a method for manufacturing an ink jet head configured to discharge ink in a pressure chamber.
[0063]
  A step of forming a vibration layer on the pressure chamber substrate for forming the pressure chamber; and at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper on the vibration layer; A step of forming a first electrode layer made of an alloy with a noble metal by sputtering; and a perovskite oxide preferentially oriented on a rhombohedral or tetragonal (001) plane on the first electrode layer. A step of forming a piezoelectric layer comprising: a step of forming a second electrode layer on the piezoelectric layer; and a step of forming a pressure chamber on the pressure chamber substrate.Thus, the content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less.Shall.
[0064]
  This makes the claim11The ink jet head according to the invention can be easily manufactured.
[0065]
  Claim20The invention includes a piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer, and a second electrode layer are sequentially stacked, and the vibration layer is formed by the piezoelectric effect of the piezoelectric layer of the piezoelectric element. The present invention is directed to a method of manufacturing an ink jet head configured to discharge ink in a pressure chamber by being displaced in the thickness direction.
[0066]
  A step of forming a vibration layer on the pressure chamber substrate for forming the pressure chamber; and at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper on the vibration layer; A step of forming a first electrode layer made of an alloy with a noble metal by sputtering, and a preferential orientation on a cubic or tetragonal (100) plane or (001) plane on the first electrode layer. A step of forming an orientation control layer comprising a perovskite oxide by a sputtering method; and a piezoelectric material comprising a perovskite oxide preferentially oriented on a rhombohedral or tetragonal (001) plane on the orientation control layer. Forming a layer by sputtering, forming a second electrode layer on the piezoelectric layer, and forming a pressure chamber on the pressure chamber substrate.Thus, the content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less.Shall.
[0067]
  This makes the claim12The ink jet head according to the invention can be easily manufactured.
[0068]
  Claim21The invention includes a substrate having a fixed portion and at least a pair of vibrating portions extending in a predetermined direction from the fixed portion, and a first electrode layer, a piezoelectric layer, and a first layer are formed on at least each vibrating portion of the substrate. Two electrode layers are sequentially stacked, and the second electrode layer on each vibration part has at least one drive electrode for vibrating the vibration part in the width direction of the vibration part, and the vibration part It is an invention of a method for manufacturing an angular velocity sensor patterned on at least one detection electrode for detecting deformation in the thickness direction.
[0069]
  And in this invention, the process of forming the 1st electrode layer which consists of an alloy of the at least 1 sort (s) of metal chosen from the group of cobalt, nickel, iron, manganese, and copper on a board | substrate by a sputtering method, Forming a piezoelectric layer made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane on the first electrode layer by sputtering, and on the piezoelectric layer Forming a second electrode layer, patterning the second electrode layer to form the drive electrode and the detection electrode, and patterning the piezoelectric layer and the first electrode layer. And a step of patterning the substrate to form the fixed portion and the vibrating portion.Thus, the content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less.Shall.
[0070]
  According to the invention, the claims13The angular velocity sensor according to the invention can be easily manufactured.
[0071]
  Claim22In the invention, a substrate having a fixed portion and at least a pair of vibrating portions extending in a predetermined direction from the fixed portion is provided, and the first electrode layer, the orientation control layer, and the piezoelectric are provided on at least each vibrating portion of the substrate. A body layer and a second electrode layer are sequentially stacked, and the second electrode layer on each vibration part has at least one drive electrode for vibrating the vibration part in the width direction of the vibration part; The present invention is directed to a method for manufacturing an angular velocity sensor patterned on at least one detection electrode for detecting deformation in the thickness direction of the vibration part.
[0072]
  Forming a first electrode layer made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper on the substrate by a sputtering method; A step of forming an orientation control layer made of a perovskite oxide preferentially oriented on a cubic or tetragonal (100) plane or (001) plane on the electrode layer, and on the orientation control layer A step of forming a piezoelectric layer made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane by sputtering, and a second electrode layer on the piezoelectric layer. A step of patterning the second electrode layer to form the drive electrode and the detection electrode; a step of patterning the piezoelectric layer, the orientation control layer, and the first electrode layer; , The above substrate - containing by training and forming the fixed portion and the vibrating portionsThus, the content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less.Shall.
[0073]
  This makes the claim14The angular velocity sensor according to the invention can be easily manufactured.
[0074]
  Claim23According to the present invention, there is provided a piezoelectric element in which a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially laminated, a vibration layer provided on a surface on the second electrode layer side of the piezoelectric element, An ink jet head having a pressure chamber member bonded to a surface of the vibration layer opposite to the piezoelectric element and having a pressure chamber for containing ink and configured to be movable relative to a recording medium, When the inkjet head is moving relative to the recording medium, the vibration layer is displaced in the layer thickness direction by the piezoelectric effect of the piezoelectric layer of the piezoelectric element in the inkjet head, and the ink in the pressure chamber is It is an invention of an ink jet recording apparatus configured to perform recording by discharging to a recording medium from a nozzle hole communicating with a pressure chamber.
[0075]
  In the present invention, the first electrode layer of the piezoelectric element in the inkjet head is made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal,The content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and not more than 26 mol%;The piezoelectric layer is made of a perovskite oxide preferentially oriented in a rhombohedral or tetragonal (001) plane.
[0076]
  According to the present invention, by using an ink jet head that can easily control ink ejection variations, it is possible to reduce variations in recording on a recording medium, and as a result, highly reliable ink jet recording. An apparatus can be realized.
[0077]
  Claim24In the invention of claim23In the invention, a perovskite oxide preferentially oriented in a cubic or tetragonal (100) plane or (001) plane is provided between the first electrode layer and the piezoelectric layer of the piezoelectric element in the inkjet head. It is assumed that an orientation control layer is provided.
[0078]
  As a result, a highly reliable ink jet recording apparatus can be obtained stably and easily.
[0079]
  Claim25In the invention, a piezoelectric element in which a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially laminated, a vibration layer provided on a surface on the first electrode layer side of the piezoelectric element, An ink jet head having a pressure chamber member bonded to a surface of the vibration layer opposite to the piezoelectric element and having a pressure chamber for containing ink and configured to be movable relative to a recording medium, When the inkjet head is moving relative to the recording medium, the vibration layer is displaced in the layer thickness direction by the piezoelectric effect of the piezoelectric layer of the piezoelectric element in the inkjet head, and the ink in the pressure chamber is The present invention is intended for an ink jet recording apparatus configured to perform recording by ejecting the recording medium from a nozzle hole communicating with a pressure chamber.
[0080]
  The first electrode layer of the piezoelectric element in the inkjet head is made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal,The content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and not more than 26 mol%;The piezoelectric layer is made of a perovskite oxide preferentially oriented in a rhombohedral or tetragonal (001) plane.
[0081]
  This makes the claim23An ink jet recording apparatus having the same effect as that of the present invention can be obtained.
[0082]
  Claim26In the invention of claim25In the invention, a perovskite oxide preferentially oriented in a cubic or tetragonal (100) plane or (001) plane is provided between the first electrode layer and the piezoelectric layer of the piezoelectric element in the inkjet head. It is assumed that an orientation control layer is provided.
[0083]
  In this way, the claims24An ink jet recording apparatus having the same effect as that of the present invention can be obtained.
[0084]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0085]
  (Embodiment 1)
  FIG. 1 is a perspective view showing a piezoelectric element according to an embodiment of the present invention. As shown in FIG. 1, the piezoelectric element 20 of this embodiment includes a substrate 1 made of silicon having a rectangular plate shape with a length of 15.0 mm, a thickness of 0.30 mm, and a width of 3.0 mm, and the silicon substrate 1. The laminated body 10 is provided. This piezoelectric element 20 has a width of 3.0 mm and a length extending in a direction perpendicular to the piezoelectric element 20 (Y-axis direction of the coordinate axis shown in FIG. 1) by the epoxy adhesive 6 at a portion from one end to 3.0 mm. It is fixed to a stainless steel support substrate 5 having a thickness of 10.0 mm and a thickness of 1.0 mm, thereby forming a cantilever beam. The substrate 1 is not limited to silicon, and may be a glass substrate, a metal substrate, a ceramic substrate, or the like.
[0086]
  The laminated body 10 includes a first electrode layer 2 disposed on the silicon substrate 1, a piezoelectric layer 3 disposed on the first electrode layer 2, and a piezoelectric layer 3 disposed on the piezoelectric layer 3. The first electrode layer 2, the piezoelectric layer 3, and the second electrode layer 4 are sequentially formed and stacked on the substrate 1 by a sputtering method. Is. The film forming method for each film is not limited to the sputtering method, and any film forming method (for example, a CVD method) for directly forming a crystalline thin film without a crystallization step by heat treatment may be used. The film forming method 4 may be a sol-gel method or the like. Further, an adhesion layer that improves adhesion between the silicon substrate 1 and the first electrode layer 2 may be formed between the silicon substrate 1 and the first electrode layer 2 (deformation of the second embodiment described later). See example). This adhesion layer may be made of one selected from the group consisting of titanium, tantalum and molybdenum.
[0087]
  The first electrode layer 2 has a thickness of 0.10 μm and is formed of an iridium (Ir) thin film containing 6 mol% of cobalt (Co). That is, the first electrode layer 2 is made of an alloy of cobalt and iridium as a noble metal. In addition to the role as an electrode, the first electrode layer 2 also serves to control the crystal orientation of the piezoelectric layer 3 as will be described later. A crystal orientation control layer is formed. The first electrode layer 2 may be made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal, and the noble metal includes platinum, iridium, What is necessary is just to be at least 1 sort (s) chosen from the group of palladium and ruthenium. In addition, the first electrode layer 2 contains an extremely small amount of oxygen in its composition in addition to an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal. It may be. The content of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper is more than 0 and not more than 26 mol% in that the crystal orientation can be controlled well.To. Furthermore, the film thickness of the 1st electrode layer 2 should just be the range of 0.05-2 micrometers.
[0088]
  The piezoelectric layer 3 is an entire surface (that is, a width of 3.0 mm) excluding a portion from one end on the side (base end side) bonded to the stainless steel support substrate 5 on the first electrode layer 2 to 3.0 mm. In the rhombohedral or tetragonal (001) plane (in the case of the rhombohedral system, the (100) plane and the (001) plane). Since it is the same as the plane, it is made of a perovskite oxide (including this rhombohedral (100) plane orientation). In this embodiment, the piezoelectric layer 3 is composed of a PZT thin film with a thickness of 2.50 μm, and the composition of this PZT is Zr / Ti = 53/47 (thus, it becomes a rhombohedral system). ). The Zr / Ti composition is not limited to Zr / Ti = 53/47, but may be Zr / Ti = 30/70 to 70/30. In addition, the constituent material of the piezoelectric layer 3 may be a piezoelectric material mainly composed of PZT, such as PZT containing additives such as Sr, Nb, Al, Mg, etc. PZT including (that is, PLZT) may be used. Furthermore, the thickness of the piezoelectric layer 3 may be in the range of 0.5 to 5.0 μm.
[0089]
  The second electrode layer 4 is made of a platinum (Pt) thin film having a thickness of 0.25 μm, and lead wires 7 and 8 are connected to the first electrode layer 2 and the second electrode layer 4, respectively. Has been. The constituent material of the second electrode layer 4 is not limited to Pt, but may be any conductive material, and the film thickness may be in the range of 0.1 to 0.4 μm.
[0090]
  When a voltage is applied between the first electrode layer 2 and the second electrode layer 4 of the piezoelectric element 20 via the lead wires 7 and 8, the piezoelectric body layer 3 has the X of the coordinate axis shown in FIG. It extends in the axial direction (the length direction of the piezoelectric layer 3). At this time, the change amount ΔL (m) of the elongation of the piezoelectric layer 3 is defined as follows: the applied voltage is E (V), the thickness of the piezoelectric layer 3 is t (m), and the length of the piezoelectric layer 3 is L (m). ), The piezoelectric constant of the piezoelectric layer 3 is d₃₁(Pm / V)
  ΔL = d₃₁× L × E / t
It becomes.
[0091]
  Here, in the piezoelectric layer 3, the upper part joined to the thin second electrode layer 4 extends in the X-axis direction, but the lower part joined to the silicon substrate 1 via the first electrode layer 2. The stretch displacement of the portion is suppressed by the thick silicon substrate 1. As a result, the distal end side of the piezoelectric element 20 located on the opposite side to the base end side (terminal side to which the lead wires 7 and 8 are connected) fixed to the stainless steel support substrate 5 is the Z axis of the coordinate axis shown in FIG. Displacement to the negative side of the direction (lower side in FIG. 1). As a result, when voltage application and removal are alternately repeated at a constant frequency, the tip of the piezoelectric element 20 moves up and down with a predetermined displacement width. The displacement characteristics of the piezoelectric element 20 can be evaluated by measuring the relationship between the applied voltage and the displacement width of the tip of the piezoelectric element 20.
[0092]
  Next, a method for manufacturing the piezoelectric element 20 will be described with reference to the process diagram of FIG.
[0093]
  First, as shown in FIG. 2A, a rectangular opening having a width of 5.0 mm and a length of 18.0 mm is formed on a 20 mm square, 0.30 mm thick silicon substrate 1 having a polished (001) surface. The thickness of the first electrode layer 2 made of an iridium film containing 6 mol% of cobalt is 0.10 μm by RF sputtering using a 0.2 mm thick stainless steel mask (not shown). To form.
[0094]
  Specifically, the iridium film containing cobalt is a ternary RF magnetron sputtering apparatus, and the silicon substrate 1 is heated and held in advance at a temperature of 400 ° C., and a mixed gas of argon and oxygen (gas volume ratio Ar) as a sputtering gas. : O₂= 15: 1), the total gas pressure is maintained at 0.25 Pa, a cobalt target is used as the first target of the ternary sputtering apparatus, an iridium target is used as the second target, and high frequencies of 100 W and 200 W, respectively. It is formed by applying power and sputtering for 15 minutes (no third target is used).
[0095]
  Subsequently, using a stainless steel mask (thickness: 0.2 mm) having a rectangular opening having a width of 5.0 mm and a length of 12.0 mm, RF magnetron sputtering is accurately performed on the surface of the first electrode layer 2. The piezoelectric layer 3 made of a PZT film having a thickness of 2.50 μm is formed by the method. A method for forming the piezoelectric layer 3 of the PZT film will be described in detail later.
[0096]
  Next, a second electrode layer 4 made of platinum having a thickness of 0.25 μm is formed by RF sputtering on the surface of the piezoelectric layer 3 using a stainless steel mask having the same shape as that for forming the piezoelectric layer 3. . As a result, a structure 21 is obtained in which the laminate 10 including the piezoelectric layer 3 is provided on the silicon substrate 1 as shown in FIG.
[0097]
  Next, as shown in FIG. 2C, in a square portion having a width of 3.0 mm and a length of 15.0 mm, and one end of which is 3.0 mm wide and 3.0 mm long. The structure 21 is cut with a dicing saw so that a part of the first electrode layer 2 is exposed. Thereby, the piezoelectric element structure component 22 in which the second electrode layer 4 is exposed on the upper side of the portion of the first electrode layer 2 having a width of 3.0 mm and a length of 12.0 mm is obtained.
[0098]
  Subsequently, as shown in FIG. 2D, one end portion of the silicon substrate 1 in the piezoelectric element structure component 22 is bonded to the stainless steel support substrate 5 using an epoxy adhesive 6.
[0099]
  Next, as shown in FIG. 2 (e), a 0.1 mm gold lead wire is used for the first electrode layer 2 exposed in the piezoelectric element structure component 22 by using a conductive adhesive (silver paste). 7 is connected, and the same lead wire 8 is connected to the second electrode layer 4 on the same one end side by wire bonding, whereby the piezoelectric element 20 is completed.
[0100]
  Here, a method for forming the piezoelectric layer 3 will be described in detail. That is, using a RF magnetron sputtering apparatus, the silicon substrate 1 on which the first electrode layer 2 made of an iridium film containing cobalt is heated and held up to 600 ° C. in a film forming chamber, and lead zirconate titanate (PbZr)_0.53Ti_0.47O₃) To form a piezoelectric layer 3 by applying a high frequency power of 600 W and sputtering for 125 minutes using a sintered body target prepared by adding lead oxide (PbO) in excess of 5 mol% in a molar ratio. To do. During this film formation, a mixed gas of argon and oxygen (gas volume ratio Ar: O₂= 19: 1) is used as the sputtering gas and the total gas pressure is kept at 0.3 Pa.
[0101]
  The piezoelectric layer 3 is crystal-grown by using cobalt scattered in the surface portion of the first electrode layer 2 on the piezoelectric layer 3 side as a nucleus, and is thereby easily oriented on the (001) plane on the cobalt. . That is, cobalt (similarly to nickel, iron, manganese, and copper) easily adsorbs oxygen in the sputtering gas when the piezoelectric layer 3 is formed, and this adsorption is a stable coordination structure with an NaCl type crystal structure. It happens by taking. As a result, PZT having a relationship between a metal atom (lead) having the same coordination and an oxygen atom is connected to the crystal to grow a crystal. At this time, since the oxygen partial pressure at the time of film formation is relatively low and the amount of oxygen in the film formation atmosphere is small, a phenomenon in which only oxygen atoms are arranged in layers (the (111) plane grows at this time) hardly occurs. The (001) plane in which metal atoms (lead) and oxygen atoms are alternately arranged in layers becomes easy to grow. On the other hand, by using the silicon substrate 1, the first electrode layer 2 is (111) -oriented, and the upper region of the piezoelectric layer 3 where no cobalt is present on the surface portion of the first electrode layer 2. Then, it becomes plane orientation other than the (001) plane (for example, (111) plane orientation) or becomes amorphous (in the case of an iridium film, it becomes amorphous). However, since the (001) plane easily grows in the film-forming atmosphere containing oxygen as described above, the crystal growth rate of the (001) plane of the PZT film on cobalt is ( This is faster than the growth of crystal grains oriented other than the (001) plane, whereby the crystal growth of the (001) plane spreads horizontally in an inverted conical shape while suppressing the growth of crystal grains oriented other than the (001) plane. . As a result, when the thickness of the piezoelectric layer 3 reaches about 20 nm, almost the entire surface becomes a (001) -oriented region. As a result, if the thickness of the piezoelectric layer 16 is 0.5 μm or more, most of the piezoelectric layer 16 becomes a region of (001) orientation, and the degree of (001) orientation (rhombohedral (100 ) Planar orientation) is 90% or more.
[0102]
  Here, a specific example will be described.
[0103]
  First, as the piezoelectric element of Example 1, the same element as that of the above embodiment was manufactured by the same manufacturing method as described above. In the course of its production, the first electrode layer and the piezoelectric layer were subjected to composition analysis using an X-ray microanalyzer, and the crystal orientation rate of the piezoelectric layer was examined by analysis using an X-ray diffraction method.
[0104]
  As a result of the composition analysis of the first electrode layer (iridium film), it was found that the composition of this film was iridium containing 6 mol% of cobalt. As a result of the compositional analysis of the piezoelectric layer (PZT film), the cation composition ratio of the PZT film is Pb: Zr: Ti = 1.00: 0.53: 0.47, and Pb (Zr_0.53Ti_0.47) O₃It was found that the chemical composition can be expressed as
[0105]
  Further, as a result of analyzing the piezoelectric layer by the X-ray diffraction method, a thin film having a perovskite crystal structure and preferentially oriented with a (001) plane crystal orientation ratio of 99% (the <001> axis is perpendicular to the surface) It turned out to be a thin film with a structure oriented in the direction. Here, the crystal orientation ratio is (001) plane, (100) plane, (010) plane, (110) plane, (011) plane, (101) plane, (111) plane of the X-ray diffraction pattern of the PZT film. The ratio (percentage) of the peak intensity of the (001) plane with respect to the total peak intensity.
[0106]
  Next, a triangular wave voltage of 0V to −10V is applied between the first electrode layer and the second electrode layer in the piezoelectric element of Example 1 produced above via a lead wire, and the coordinate axis shown in FIG. The amount of displacement of the tip of the piezoelectric element that moves up and down in the Z-axis direction was measured.
[0107]
  FIG. 3 shows the amount of displacement of the tip of the piezoelectric element when a voltage having a frequency of 100 Hz is applied. As shown in FIG. 3, when a voltage of 0 V to −10 V was applied, the maximum displacement amount at the tip of the piezoelectric element was 3.8 μm.
[0108]
  Here, under the same conditions as those of the piezoelectric element of the first embodiment, three pieces having a first electrode layer formed on a silicon substrate are prepared, and using these, the same PZT film as that of the piezoelectric element of the first embodiment is prepared. Formed. However, at this time, the films were formed by selecting the sputtering time of the three substrates as 2 minutes, 5 minutes, and 20 minutes, respectively. The thicknesses of the PZT films thus formed were 0.02 μm, 0.09 μm, and 0.40 μm, respectively. The (001) plane crystal orientation ratio of these PZT films was examined by an X-ray diffraction method.
[0109]
  As a result, the (001) plane crystal orientation ratio of the PZT film is 85% when the PZT film thickness is 0.02 μm, 95% when 0.09 μm, and 0.40 μm when it is 0.40 μm. It was 98%. From this, it has been found that the crystal orientation of the PZT film gradually becomes dominant in the (001) plane orientation as the film grows from the surface on the first electrode side.
[0110]
  Next, each element of the ternary RF magnetron sputtering apparatus is replaced with a different material, and the sputtering power and the sputtering time are controlled, whereby piezoelectric elements having first electrode layers having different compositions and film thicknesses (Example 2) To Example 39) were prepared. Table 1 shows the composition, sputtering power, and sputtering time of each target when forming the first electrode layer.
[0111]
[Table 1]

[0112]
  Then, as in Example 1, the film thickness measurement and composition analysis of the first electrode layer in each of the piezoelectric elements of Examples 2 to 39 were performed, and the (001) plane crystal orientation ratio of the piezoelectric layer was measured. Further, the displacement amount (maximum displacement amount) of the tip of the piezoelectric element when a triangular wave voltage was applied was measured. The results are summarized in Table 2.Although Examples 9, 17, 21, 26 and 31 are referred to as “Examples” for the sake of convenience, the results of the composition analysis of the first electrode layer are no longer the subject of the present invention.
[0113]
[Table 2]

[0114]
  From this, the (001) plane crystal orientation ratio of the piezoelectric layer in each example is considerably higher than that of the comparative example described later. In particular, in the first electrode layer, cobalt, nickel, iron, manganese and copper are used. It can be seen that if the content of at least one metal selected from this group is 26 mol% or less, it will surely be 90% or more and the maximum displacement of the tip of the piezoelectric element will also be at a high level.
[0115]
  The piezoelectric layers of the piezoelectric elements of Examples 1 to 39 were PZT films having a constant composition, but similar results were obtained with PZT films having different Ti / Zr molar ratios. The piezoelectric layer may be a PZT film containing La (PLZT film) or a PZT film containing ions such as Nb and Mg, and any oxide film having a perovskite crystal structure can be used. A (001) plane oriented film was obtained in the same manner as each piezoelectric element of Example 39.
[0116]
  Next, the following piezoelectric elements were produced as comparative examples (Comparative Example 1 and Comparative Example 2).
[0117]
  That is, in the piezoelectric element of Comparative Example 1, a piezoelectric thin film was formed by sputtering according to the description of Japanese Patent Application Laid-Open No. 2001-88294 as part of the manufacturing process. Specifically, first, using a sputtering apparatus, a silicon substrate similar to that used in Example 1 was placed in an electric furnace at 1100 ° C., and was oxidized for 22 hours by flowing dry oxygen to form a surface layer. A silicon oxide film having a thickness of about 1 μm was formed. On the surface of the substrate, a zirconium oxide thin film having a thickness of 0.4 μm was formed by reactive sputtering while introducing oxygen using oxygen as a target (sputtering conditions: sputtering power 200 W, vacuum 0.3 Pa), A first electrode layer made of an iridium thin film having a film thickness of 1.0 μm is formed on the surface using an RF magnetron sputtering apparatus targeting iridium, and the same stainless steel mask as that in the above embodiment is further used on the surface. A titanium thin film having a film thickness of 0.06 μm was formed using a DC magnetron sputtering apparatus targeting titanium. Further, a PZT film having the same composition as in Example 1 is formed on the surface of the titanium film by the same method as in Example 1. Further, a platinum thin film having a film thickness of 0.25 μm as in Example 1 is formed. 2 electrode layers were formed and then processed in the same manner as in Example 1 to produce a piezoelectric element having the same shape as in Example 1 (FIG. 1).
[0118]
  When the (001) plane crystal orientation ratio of the PZT film of the piezoelectric layer in the piezoelectric element of Comparative Example 1 was examined, it was 23%. Further, when the amount of displacement of the tip of the piezoelectric element of Comparative Example 1 when a triangular wave voltage was applied was measured, the result shown in FIG. 4 was obtained, and the maximum amount of displacement was 2.4 μm (note that the crystal orientation ratio and Each value of the maximum displacement is shown in Table 2 together with the above-described example and comparative example 2 described later).
[0119]
  In the configuration of the piezoelectric element of Comparative Example 1 described above, when the sputtering method is used for the production of the piezoelectric layer, it is difficult to control the crystal orientation of the piezoelectric thin film as described in JP-A-2001-88294. It can be seen that a PZT film with high (001) plane crystal orientation cannot be obtained.
[0120]
  Next, a piezoelectric element of Comparative Example 2 was produced. The comparative example 2 is different from the above example in that the iridium film of the first electrode layer does not contain a metal such as cobalt. That is, when the first electrode layer is formed, sputtering is performed for 16 minutes by setting the sputtering power to the cobalt target of the first target to 0 W and the sputtering power to the iridium target of the second target to 200 W. As a result, a first electrode layer (iridium film) having a thickness of 0.10 μm, which is considered not to function as a crystal orientation control layer, was formed, and a piezoelectric element was fabricated in exactly the same manner as in Example 1.
[0121]
  When the piezoelectric layer in the piezoelectric element of Comparative Example 2 is analyzed by the X-ray diffraction method, it is not a (001) plane-oriented thin film as in Example 1, and the (111) plane other than the (001) plane An X-ray diffraction pattern including a diffraction peak having a high intensity on the (110) plane was shown, and the (001) plane crystal orientation ratio was 22%. This is because the first electrode layer does not contain a metal such as cobalt, so it did not function as a crystal orientation control layer, and as a result, the (001) plane crystal orientation ratio of the PZT film thereon was increased. It is thought that it fell.
[0122]
  Further, when the amount of displacement of the tip of the piezoelectric element of Comparative Example 2 when a triangular wave voltage was applied was measured, the maximum amount of displacement was 2.3 μm.
[0123]
  Next, instead of a silicon substrate (length 15.0 mm, thickness 0.30 mm, width 3.0 mm strip flat plate) as a substrate, heat-resistant crystallized glass (thickness 0.30 mm: not deformed even at 700 ° C.) Thermal expansion coefficient 87 × 10^―7A piezoelectric element having the same shape as that of Example 1 was manufactured by the same method as in Example 1 using a strip-shaped flat plate substrate having a length of 15.0 mm and a width of 3.0 mm (/ ° C.). Example 40).
[0124]
  Further, using the same substrate as in Example 40, a piezoelectric element manufactured in the same manner as in Example 7 (Example 41), a piezoelectric element manufactured in the same manner as in Example 13 (Example 42), A piezoelectric element manufactured in the same manner as in Example 19 (Example 43), a piezoelectric element manufactured in the same manner as in Example 32 (Example 44), and a first element manufactured in the same manner as in Comparative Example 2 above. A piezoelectric element (Comparative Example 3) having an electrode layer made of only iridium was obtained.
[0125]
  The film thickness measurement and composition analysis of the first electrode layer in each of the piezoelectric elements of Examples 40 to 44 and Comparative Example 3 manufactured using the glass substrate as described above were performed, and the piezoelectric layer (001) The plane crystal orientation ratio was examined, and the displacement amount (maximum displacement amount) of the tip of the piezoelectric element when a triangular wave voltage was applied was measured. The results are shown in Table 3.
[0126]
[Table 3]

[0127]
  Therefore, even when the substrate is made of glass different from silicon, the piezoelectric element having the configuration of this example includes a piezoelectric layer having a crystal orientation on the (001) plane with a high orientation ratio and high piezoelectric displacement. It turns out that it becomes possible. Further, it was found that although the amount of displacement at the time of voltage application differs depending on the substrate material, stable displacement characteristics are exhibited.
[0128]
  (Embodiment 2)
  FIG. 5 shows another piezoelectric element according to the embodiment of the present invention (the same parts as those in FIG. 1 are denoted by the same reference numerals and detailed description thereof is omitted). An orientation control layer 11 is provided between the first electrode layer 2 and the piezoelectric layer 3.
[0129]
  That is, the piezoelectric element 20 of the present embodiment includes the silicon substrate 1 and the laminated body 10 disposed on the silicon substrate 1 as in the first embodiment, and from one end to 3.0 mm. In this part, it is fixed to the stainless steel support substrate 5 by the epoxy adhesive 6, thereby forming a cantilever beam. Also in this embodiment, the substrate 1 is not limited to silicon, and may be a glass substrate, a metal substrate, a ceramic substrate, or the like.
[0130]
  The stacked body 10 includes a first electrode layer 2 disposed on the silicon substrate 1, an alignment control layer 11 disposed on the first electrode layer 2, and an alignment control layer 11. The piezoelectric layer 3 provided and the second electrode layer 4 disposed on the piezoelectric layer 3, the first electrode layer 2, the orientation control layer 11, The piezoelectric layer 3 and the second electrode layer 4 are sequentially formed by sputtering and stacked. In the present embodiment, the film forming method for each film is not limited to the sputtering method, but may be any film forming method (for example, CVD method) that directly forms a crystalline thin film without a crystallization step by heat treatment. The film formation method of the second electrode layer 4 may be a sol-gel method or the like.
[0131]
  As in the first embodiment, the first electrode layer 2 is made of an alloy of cobalt and iridium. In addition to the role as an electrode, the orientation control layer 11 and the crystal orientation of the piezoelectric layer 3 are also provided. The electrode and crystal orientation control layer that also plays the role of controlling is formed. However, in this embodiment, the cobalt content is 1 mol% and the thickness is 0.22 μm. In the present embodiment, the first electrode layer 2 only needs to be made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal. May be at least one selected from the group consisting of platinum, iridium, palladium and ruthenium. In addition, the first electrode layer 2 contains an extremely small amount of oxygen in its composition in addition to an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal. It may be. The content of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper is more than 0 and not more than 26 mol% in that the crystal orientation can be controlled well.To. Furthermore, the film thickness of the 1st electrode layer 2 should just be the range of 0.05-2 micrometers.
[0132]
  The orientation control layer 11 is made of a perovskite oxide that is preferentially oriented in a cubic or tetragonal (100) plane or (001) plane. In this embodiment, it is made of lead lanthanum titanate (composition ratio Pb: La: Ti = 1.12: 0.08: 1.00), and the film thickness is 0.02 μm. The orientation control layer 11 is controlled in crystal orientation by the first electrode layer 2, thereby controlling the crystal orientation of the piezoelectric layer 3. The material constituting the orientation control layer 11 is not limited to lead lanthanum titanate, and may be one obtained by adding at least one of magnesium and manganese to this lead lanthanum titanate. A perovskite oxide containing strontium that can be formed at a lower temperature than PZT or the like may be used. In this case, inter alia, strontium titanate (SrTiO₃) Is preferably contained, and only this strontium titanate may be contained, and in addition to strontium titanate, lead titanate, lead lanthanum titanate, barium titanate and the like may be contained. Moreover, the film thickness of the orientation control layer 11 should just be the range of 0.01-0.2 micrometer.
[0133]
  The piezoelectric layer 3 is made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane, as in the first embodiment, and is a 2.50 μm thick PZT thin film ( Zr / Ti = 53/47). In the present embodiment, the Zr / Ti composition is not limited to Zr / Ti = 53/47, but may be Zr / Ti = 30/70 to 70/30. In addition, the constituent material of the piezoelectric layer 3 may be a piezoelectric material mainly composed of PZT, such as PZT containing additives such as Sr, Nb, Al, Mg, etc. PZT including (that is, PLZT) may be used. Furthermore, the thickness of the piezoelectric layer 3 may be in the range of 0.5 to 5.0 μm.
[0134]
  The second electrode layer 4 is made of a platinum thin film having a thickness of 0.25 μm as in the first embodiment. However, the second electrode layer 4 may be made of a conductive material and has a thickness of 0.1 to 0.4 μm. Any range is acceptable.
[0135]
  As in the first embodiment, a voltage is applied between the first and second electrode layers 2 and 4 via the lead wires 7 and 8 connected to the first and second electrode layers 2 and 4, respectively. The displacement characteristics of the piezoelectric element 20 can be evaluated by measuring the relationship between the applied voltage and the displacement width of the tip of the piezoelectric element 20.
[0136]
  Next, a method for manufacturing the piezoelectric element 20 will be described with reference to the process diagram of FIG.
[0137]
  First, as in the first embodiment, a stainless steel mask having a rectangular opening having a width of 5.0 mm and a length of 18.0 mm is used on a 20 mm square silicon substrate 1 having a polished (001) surface. Then, the first electrode layer 2 made of an iridium film containing 1 mol% of cobalt is formed by RF sputtering (refer to the column of Example 45 in Table 4 to be described later) (see FIG. 6A). ).
[0138]
  Subsequently, using a stainless steel mask having a rectangular opening having a width of 5.0 mm and a length of 12.0 mm, the thickness of the surface of the first electrode layer 2 is accurately adjusted by RF magnetron sputtering. An orientation control layer 11 made of a lead lanthanum titanate film having a thickness of 02 μm is formed, and then a piezoelectric layer 3 made of a PZT film having a thickness of 2.50 μm is accurately formed on the surface of the orientation control layer 11 by RF magnetron sputtering. Form. A method for forming the orientation control layer 11 and the piezoelectric layer 3 will be described in detail later.
[0139]
  Next, as in the first embodiment, the structure 21 in which the second electrode layer 4 is formed on the surface of the piezoelectric layer 3 by RF sputtering and the stacked body 10 is provided on the silicon substrate 1 is formed. Obtained (see FIG. 6B).
[0140]
  Next, the structure 21 is cut with a dicing saw so as to have the same shape as that of the first embodiment, and the piezoelectric element structure component 22 is obtained (see FIG. 6C).
[0141]
  Subsequently, as in the first embodiment, one end portion of the silicon substrate 1 in the piezoelectric element structure component 22 is bonded to the stainless steel support substrate 5 using the epoxy adhesive 6 (see FIG. 6D). Next, the lead wire 7 is connected to the first electrode layer 2 exposed in the piezoelectric element structure part 22 and the lead wire 8 is connected to the second electrode layer 4, thereby the piezoelectric element 20. Is completed (see FIG. 6E).
[0142]
  Here, a method for forming the orientation control layer 11 and the piezoelectric layer 3 will be described in detail. In other words, an RF magnetron sputtering apparatus having two film forming chambers having the same structure and capable of moving a substrate on which a thin film is to be formed from one film forming chamber to the other film forming chamber without breaking the vacuum is used. In the film chamber, a stoichiometric lead lanthanum titanate (Mb ratio: Pb: La: Ti = 0.92: 0.08: 1.00) was added to PbO in an excess of about 20 mol% to prepare a sintered mixture. A body target (composition molar ratio Pb: La: Ti = 1.12: 0.08: 1.00) was attached, and the other film formation chamber was lead zirconate titanate (PbZr)._0.53Ti_0.47O₃) Is attached to a sintered body target prepared by adding 5 mol% of lead oxide (PbO) in a molar ratio to the silicon substrate 1 on which the first electrode layer 2 is formed. Thus, the orientation control layer 11 and the piezoelectric layer 3 are formed.
[0143]
  Specifically, first, the silicon substrate 1 on which the first electrode layer 2 is formed is preliminarily heated and maintained at a temperature of 550 ° C. in the film formation chamber in which the target of lead lanthanum titanate is attached, A thin film having a film thickness of 0.02 μm made of lead lanthanum titanate containing a perovskite crystal structure with the <001> axis growing in a direction perpendicular to the surface and containing excess lead is formed. At this time, a mixed gas of argon and oxygen (gas volume ratio Ar: O₂= 19: 1) is used as the sputtering gas, the total gas pressure is kept at 0.3 Pa, high frequency power of 300 W is applied, and sputtering is performed for 10 minutes.
[0144]
  Next, the silicon substrate 1 on which the orientation control layer 11 is formed is transferred to a film forming chamber equipped with a target of lead zirconate titanate without breaking the vacuum, and the substrate 1 is heated to a temperature of 500 ° C. therein. Pb having a thickness of 2.50 μm on the orientation control layer 11_1.00(Zr_0.53Ti_0.47) O₃Is formed. At this time, a mixed gas of argon and oxygen (gas volume ratio Ar: O₂= 19: 1) is used as the sputtering gas, the total gas pressure is kept at 0.3 Pa, high frequency power of 700 W is applied, and sputtering is performed for 50 minutes.
[0145]
  Similar to the piezoelectric layer 3 in the first embodiment, the orientation control layer 11 is crystal-grown using cobalt scattered on the surface portion of the first electrode layer 2 on the orientation control layer 11 side as a nucleus. , It becomes easy to orient on the (100) plane or the (001) plane on cobalt. In addition, by forming the orientation control layer 11 with lead lanthanum titanate, the (100) plane or (001) plane orientation film can be easily and stably formed at a relatively low temperature. If the piezoelectric layer 3 made of PZT is formed on the orientation control layer 11 thus formed, lead lanthanum titanate and PZT have exactly the same crystal structure. PZT having a similar arrangement is grown as it is, and the orientation control layer 11 causes the piezoelectric layer 3 to have the (001) plane orientation (in the rhombohedral system, the (100) plane and the (001) plane are the same). Therefore, this rhombohedral (100) orientation is included), and the (001) orientation of the piezoelectric layer 3 (the rhombohedral (100) orientation) is 90% or more.
[0146]
  In the orientation control layer 11, a region that is not oriented in the (100) plane or the (001) plane exists not only in the vicinity of the surface of the first electrode layer 2 but also on the surface on the piezoelectric layer 3 side. Also good. Even in such a case, if the layer thickness of the orientation control layer 11 is 0.01 μm or more, most of the surface on the piezoelectric layer 3 side is a (100) plane or (001) plane orientation region, The (001) plane orientation degree of the piezoelectric layer 3 can be 90% or more.
[0147]
  FIG. 7 shows a modification of the piezoelectric element 20 of the second embodiment (note that the same parts as those in FIG. 5 are given the same reference numerals and their detailed description is omitted), and the silicon substrate 1 and the first electrode are omitted. The adhesion layer 14 is disposed between the layer 2 and the layer 2.
[0148]
  That is, the piezoelectric element 20 of this modification has the same configuration as that of the second embodiment except for the adhesion layer 14. However, the constituent material and thickness of the first electrode layer 2 are different, and the first electrode layer 2 is made of a platinum film having a thickness of 0.15 μm containing 14 mol% of cobalt.
[0149]
  The adhesion layer 14 enhances the adhesion between the silicon substrate 1 and the first electrode layer 2 and is made of titanium and has a film thickness of 0.006 μm. In addition, the adhesion layer 14 should just consist of 1 type chosen from the group of titanium, a tantalum, and molybdenum, and the film thickness should just be the range of 0.005-1 micrometer.
[0150]
  A method of manufacturing this piezoelectric element will be described with reference to FIG.
[0151]
  That is, on a 20 mm square silicon substrate 1 having a polished (001) surface, a stainless steel mask having a rectangular opening with a width of 5.0 mm and a length of 18.0 mm is used, and the thickness is increased by RF sputtering. An adhesion layer 14 made of a titanium film having a thickness of 0.006 μm is formed. The titanium film is formed by sputtering the substrate 1 at a temperature of 400 ° C., using argon gas as a sputtering gas, holding the gas pressure at 1 Pa, and sputtering at a sputtering power of 100 W for 2 minutes. Then, the first electrode layer 2 made of a platinum film containing 14 mol% of cobalt is formed on the adhesion layer 14 in the same manner as in the second embodiment using the same stainless steel mask as described above. It forms so that it may be set to 0.15 micrometer (refer Fig.8 (a)).
[0152]
  Subsequently, in the same manner as in the second embodiment, the orientation control layer 11 is formed on the first electrode layer 2, the piezoelectric layer 3 is formed on the orientation control layer 11, and the piezoelectric layer 3 Then, the second electrode layer 4 is formed to obtain the structure 21 in which the stacked body 10 is provided on the silicon substrate 1 (see FIG. 8B).
[0153]
  Next, in the same manner as in the second embodiment, the structure 21 is accurately cut with a dicing saw to produce a piezoelectric element structure component 22 (see FIG. 8C), and then one end of the silicon substrate 1 is formed. Is bonded to the stainless steel support substrate 5 (see FIG. 8D). Then, by connecting the lead wires 7 and 8 to the first and second electrode layers 2 and 4, respectively, the piezoelectric element 20 is completed (see FIG. 8E).
[0154]
  Thus, by providing the adhesion layer 14 between the silicon substrate 1 and the first electrode layer 2, the adhesion between the silicon substrate 1 and the first electrode layer 2 can be improved. Film peeling at the time of manufacturing the piezoelectric element 20 can be prevented, and film peeling hardly occurs even during operation by applying a voltage between the first and second electrode layers 2 and 4.
[0155]
  Here, a specific example will be described.
[0156]
  First, as the piezoelectric element of Example 45, the same piezoelectric element as in FIG. 5 was produced by the same manufacturing method as described above. During the production, composition analysis was performed on each of the first electrode layer, the orientation control layer, and the piezoelectric layer, and the crystal orientation rate of the piezoelectric layer was examined by analysis using an X-ray diffraction method.
[0157]
  As a result of analyzing the composition of the first electrode layer (iridium film) with an X-ray microanalyzer, it was found that the composition of the film was iridium containing 1 mol% of cobalt. In addition, as a result of composition analysis using an X-ray photoelectron spectroscopy (XPS) apparatus while comparing the orientation control layer (lead lanthanum titanate film) with the target, the composition of this thin film has a molar ratio Pb: La of the same composition as the target composition. : Ti = 1.12: 0.08: 1.00. Further, the composition of the piezoelectric layer (PZT film) was analyzed with an X-ray microanalyzer. As a result, the cation composition ratio of the PZT film was Pb: Zr: Ti = 1.00: 0.53: 0.47. , Pb (Zr_0.53Ti_0.47) O₃It was found that the chemical composition can be expressed as
[0158]
  Further, as a result of analyzing the piezoelectric layer by the X-ray diffraction method, a thin film having a perovskite crystal structure and preferentially oriented with a (001) plane crystal orientation ratio of 99.5% (<001> axis is the surface) It was found that the thin film was oriented in a direction perpendicular to the surface.
[0159]
  Next, a triangular wave voltage of 0 V to −25 V was applied via a lead wire between the first electrode layer and the second electrode layer in the piezoelectric element of Example 45 produced above, and the coordinate axis shown in FIG. The amount of displacement of the tip of the piezoelectric element that moves up and down in the Z-axis direction was measured.
[0160]
  FIG. 9 shows the amount of displacement of the tip of the piezoelectric element when a voltage having a frequency of 50 Hz is applied. As shown in FIG. 9, when a voltage of 0 V to −25 V was applied, the maximum displacement at the tip of the piezoelectric element was 10.8 μm.
[0161]
  Further, when a triangular wave voltage of 0V to −30V is applied between the first electrode layer and the second electrode layer in this piezoelectric element, a triangular wave voltage of 0V to −40V is applied, and 0V to When a triangular wave voltage of −50 V was applied (in either case, the voltage frequency was 50 Hz and driven for 2 hours), the occurrence of cracks in the piezoelectric layer was examined, and no cracks were found.
[0162]
  Here, under the same conditions as those of the piezoelectric element of Example 45, three pieces having a first electrode layer and an orientation control layer formed on a silicon substrate were prepared, and using these, the piezoelectric element of Example 45 was used. The same PZT film was formed. However, at this time, the films were formed by selecting the sputtering time of the three substrates as 2 minutes, 5 minutes, and 20 minutes, respectively. The thicknesses of the PZT films thus formed were 0.02 μm, 0.09 μm, and 0.40 μm, respectively. The (001) plane crystal orientation ratio of these PZT films was examined by an X-ray diffraction method.
[0163]
  As a result, the (001) plane crystal orientation ratio of the PZT film is 93% when the PZT film thickness is 0.02 μm, 98% when 0.09 μm, and 0.40 μm when it is 0.40 μm. 99%. From this, it was found that the crystal orientation of the PZT film gradually became dominant in the (001) plane orientation as the film was grown from the surface on the orientation control layer side.
[0164]
  Next, each target of the ternary RF magnetron sputtering apparatus is replaced with a different material to control the sputtering power and the sputtering time, and to control the composition and sputtering time of the sputtering apparatus target used for forming the orientation control layer. Thus, piezoelectric elements (Examples 46 to 56) having first electrode layers and orientation control layers having different compositions and film thicknesses were produced. Table 4 shows the composition of each target when forming the first electrode layer, sputtering power and sputtering time, and the composition and sputtering time of the target when forming the orientation control layer.
[0165]
[Table 4]

[0166]
  As in Example 45, the film thickness measurement and composition analysis of the first electrode layer and the orientation control layer in each of the piezoelectric elements of Examples 46 to 56 were performed, and the (001) of the piezoelectric layer was measured. The plane crystal orientation ratio was examined, and the displacement amount (maximum displacement amount) of the tip of the piezoelectric element when a triangular wave voltage of 0 V to −25 V was applied was measured. Further, when a triangular wave voltage of 0V to −30V is applied, when a triangular wave voltage of 0V to −40V is applied, and when a triangular wave voltage of 0V to −50V is applied (in either case, the voltage frequency is 50 Hz and 2 For each (time drive), the presence or absence of cracks in the piezoelectric layer was examined. The results are summarized in Table 5.Although Examples 49 and 52 are referred to as “Examples” for the sake of convenience, the results of the composition analysis of the first electrode layer are no longer the subject of the present invention.
[0167]
[Table 5]

[0168]
  From this, the (001) plane crystal orientation ratio of the piezoelectric layer in each example is higher than that of Comparative Example 4 described later, and in particular, in the first electrode layer, cobalt, nickel, iron, manganese and copper It can be seen that if the content of at least one metal selected from this group is 26 mol% or less, it will surely be 90% or more and the maximum displacement of the tip of the piezoelectric element will also be at a high level.
[0169]
  In addition, even when an Mn-added lanthanum lead titanate film or an Mg-added lanthanum lead titanate film is used as the orientation control layer, a piezoelectric element similar to Example 45 using the lead lanthanum titanate film can be obtained. I understand.
[0170]
  The piezoelectric layers of the piezoelectric elements of Examples 45 to 56 were PZT films with a constant composition, but similar results were obtained with PZT films with different Ti / Zr molar ratios. The piezoelectric layer may be a PZT film containing La (PLZT film) or a PZT film containing ions such as Nb and Mg, and any oxide film having a perovskite crystal structure can be used. A (001) plane orientation film was obtained in the same manner as in each of the piezoelectric elements of Example 56. Furthermore, even when a strontium titanate film was used as the alignment control layer, a (001) plane alignment film was obtained.
[0171]
  Next, as a comparative example, the following piezoelectric elements were produced (Comparative Example 4 and Comparative Example 5).
[0172]
  That is, the piezoelectric element of Comparative Example 4 differs from that of the above example in that no metal such as cobalt is contained in the iridium film of the first electrode layer. Specifically, when the first electrode layer is formed, sputtering is performed for 16 minutes by setting the sputtering power to the cobalt target of the first target to 0 W and the sputtering power to the iridium target of the second target to 200 W. Thus, a first electrode layer (iridium film) having a thickness of 0.10 μm, which is considered not to function as a crystal orientation control layer, was formed, and the piezoelectric element was fabricated in exactly the same manner as in Example 45.
[0173]
  When the orientation control layer in the piezoelectric element of Comparative Example 4 is analyzed by the X-ray diffraction method, it does not become a (100) plane or (001) plane oriented thin film, but (111) other than the (100) plane and (001) plane. An X-ray diffraction pattern including a diffraction peak with high intensity on the plane and the (110) plane was shown. When the (001) plane crystal orientation ratio of the piezoelectric layer in the piezoelectric element of Comparative Example 4 was examined by the X-ray diffraction method, it was 65%. This is presumably because the crystal orientation of the orientation control layer was poor, and the PZT film on the orientation control layer also lowered the orientation rate due to the influence.
[0174]
  Further, when the amount of displacement of the tip of the piezoelectric element of Comparative Example 1 when a triangular wave voltage was applied was measured, the maximum amount of displacement was 7.7 μm.
[0175]
  Next, a piezoelectric element having a configuration without an orientation control layer with respect to that of Example 45 was prepared. This piezoelectric element is different from Example 45 only in that there is no orientation control layer, and the others are exactly the same as Example 45. That is, in forming the piezoelectric layer, the substrate temperature is heated to 500 ° C., and a mixed gas of argon and oxygen (gas volume ratio Ar: O₂= 19: 1) was used as the sputtering gas, the total gas pressure was kept at 0.3 Pa, 700 W high-frequency power was applied, and sputtering was performed for 50 minutes to form a PZT film having a thickness of 2.50 μm.
[0176]
  However, the piezoelectric layer is not a PZT film having a perovskite-type crystal structure that exhibits the desired piezoelectric characteristics from X-ray diffraction analysis, and is generally a pyrochlore-type crystal phase that does not exhibit piezoelectric characteristics that can be formed at lower temperatures than lead, titanium, and zircon. The composition was an oxide film (film thickness 3.5 μm). Therefore, it was found that without the orientation control layer, a piezoelectric layer composed of a PZT film having a perovskite crystal structure cannot be formed at a temperature of 500 ° C.
[0177]
  Therefore, a piezoelectric element having a configuration in which the formation temperature of the piezoelectric layer was set to 600 ° C. and the orientation control layer was not provided was manufactured, and this piezoelectric element was used as Comparative Example 5.
[0178]
  The (001) plane crystal orientation ratio of Comparative Example 5 is very good at 100%, and the displacement amount (maximum displacement amount) of the tip of the piezoelectric element when a triangular wave voltage of 0 to −25 V is applied is 12.5 μm. there were. However, when driven by applying a triangular wave voltage of 0 to −40 V, a minute crack was formed on the film surface, and after 40 minutes from the start of driving, the piezoelectric element was peeled off due to film peeling. This is because the formation temperature of the piezoelectric layer is 600 ° C., which is 100 ° C. higher than that in the case where there is an orientation control layer, and therefore the heat of the silicon substrate and the PZT film is reduced to the room temperature after the PZT film formation. It is considered that the film was broken because a larger tensile stress acts on the PZT film due to the difference in expansion coefficient, and the PZT film is contracted by driving.
[0179]
  Next, the same piezoelectric element as that shown in FIG. 7 was manufactured by the same manufacturing method as above (this is referred to as Example 57). In addition, each target of the ternary RF magnetron sputtering apparatus is replaced with a different material, the sputtering power and the sputtering time are controlled, and the composition and sputtering time of the sputtering apparatus target used for forming the orientation control layer are controlled. Piezoelectric elements having a first electrode layer, an orientation control layer, and an adhesion layer having different compositions and film thicknesses by controlling the composition and sputtering time of the target of the sputtering apparatus used for forming the adhesion layer (Examples 58 to Example 64) was prepared. The composition of each target when forming the first electrode layer, the sputtering power and the sputtering time, and the composition and sputtering time of the target when forming each layer of the orientation control layer and the adhesion layer are those of Example 57 above. Table 6 also shows the results.
[0180]
[Table 6]

[0181]
  For each of the piezoelectric elements in Examples 57 to 64, the same evaluation as in Examples 45 to 56 was performed. The results are shown in Table 7.
[0182]
[Table 7]

[0183]
  Accordingly, even when an adhesion layer is provided between the substrate and the first electrode layer, at least one metal selected from the group consisting of cobalt, nickel, iron, manganese, and copper is used in the first electrode layer. It can be seen that by making the content 26 mol% or less, the (001) plane crystal orientation ratio can be made 90% or more and the maximum displacement amount of the tip of the piezoelectric element can be maintained at a high level.
[0184]
  In addition, even when an Mn-added lanthanum titanate film or an Mg-added lanthanum lead titanate film is used as the orientation control layer, a piezoelectric element with good characteristics similar to that of Example 57 using the lanthanum lead titanate film is obtained It turns out that it is obtained.
[0185]
  Furthermore, it can be seen that the same piezoelectric element as in Example 57 can be obtained even when tantalum or molybdenum is used instead of titanium as the material of the adhesion layer.
[0186]
  The piezoelectric layers of the piezoelectric elements of Examples 57 to 64 were PZT films having a constant composition. However, similar results were obtained with PZT films having different Ti / Zr molar ratios. The piezoelectric layer may be either a PZT film containing La (PLZT film) or a PZT film containing ions such as Nb and Mg, and any oxide film having a perovskite crystal structure can be used. A (001) plane orientation film was obtained in the same manner as in each of the piezoelectric elements of Example 64. Furthermore, even when a strontium titanate film was used as the alignment control layer, a (001) plane alignment film was obtained.
[0187]
  Next, a borosilicate glass (# 7089, thermal expansion coefficient 45) having a thickness of 0.30 mm is used as a substrate instead of a silicon substrate (a strip plate shape having a length of 15.0 mm, a thickness of 0.30 mm, and a width of 3.0 mm). × 10^―7A piezoelectric element having the same shape as that of Example 45 was manufactured by the same method as that of Example 45 using a rectangular plate-shaped substrate having a length of 15.0 mm and a width of 3.0 mm. The device is referred to as Example 65).
[0188]
  Further, using the same substrate as in Example 65, a piezoelectric element manufactured in the same manner as in Example 46 (Example 66), a piezoelectric element manufactured in the same manner as in Example 47 (Example 67), A piezoelectric element manufactured in the same manner as in Example 48 (Example 68), a piezoelectric element manufactured in the same manner as Example 50 (Example 69), and a piezoelectric element manufactured in the same manner as Example 51 (Example) 70), a piezoelectric element manufactured in the same manner as in Example 53 (Example 71), a piezoelectric element manufactured in the same way as in Example 54 (Example 72), and a piezoelectric element manufactured in the same manner as in Example 55. An element (Example 73) and a piezoelectric element (Comparative Example 6) produced in the same manner as in Comparative Example 4 and having a first electrode layer made only of iridium were obtained.
[0189]
  Evaluations similar to those of Examples 45 to 56 were made on the piezoelectric elements of Examples 65 to 73 and Comparative Example 6 manufactured using the borosilicate glass substrate as described above. The results are shown in Table 8.
[0190]
[Table 8]

[0191]
  Therefore, even when the substrate is made of glass different from silicon, the piezoelectric element having the configuration of this example has a piezoelectric layer having a crystal orientation in the (001) plane with a high orientation ratio, and a large piezoelectric element. It can be seen that displacement can be obtained. Further, it was found that although the amount of displacement at the time of voltage application differs depending on the hardness of the substrate material, stable displacement characteristics are exhibited.
[0192]
  A piezoelectric element having no orientation control layer was fabricated for the above Example 65, but the piezoelectric layer was a PZT film having a perovskite crystal structure that showed the desired piezoelectric characteristics from X-ray diffraction analysis. In general, it was an oxide film (thickness: 3.5 μm) composed of lead, titanium, and zircon having a pyrochlore type crystal structure that does not exhibit piezoelectric properties that can generally be achieved at low temperatures. Accordingly, it was found that even when the substrate is made of glass, a piezoelectric layer made of a PZT film having a perovskite crystal structure cannot be formed at a temperature of 500 ° C. without an orientation control layer.
[0193]
  (Embodiment 3)
  Next, an ink jet head using the laminated film structure of the piezoelectric element of the present invention will be described.
[0194]
  FIG. 10 is a schematic configuration diagram illustrating an inkjet head according to an embodiment of the present invention. As shown in FIG. 10, the inkjet head 201 of this embodiment includes a plurality of (10 in FIG. 10) ink ejection elements 202 having the same shape arranged in a line, and the ink ejection elements 202. And a driving power source element 203 such as an IC chip for driving the IC.
[0195]
  FIG. 11 is an exploded perspective view, partly broken away, showing the configuration of each of the ink ejection elements 202. In FIG. 11, A is a pressure chamber member made of glass, and the pressure chamber opening 31 is formed in the pressure chamber member A. B is an actuator portion arranged so as to cover the upper end opening surface of the pressure chamber opening 31 (size: an ellipse having a minor axis of 200 μm and a major axis of 400 μm), and C is the pressure chamber opening 31. It is an ink flow path member arranged so as to cover the lower end opening surface. That is, the pressure chamber opening 31 of the pressure chamber member A is partitioned by the actuator portion B and the ink flow path member C positioned above and below, thereby forming the pressure chamber 32 (depth 0.2 mm). Yes.
[0196]
  The actuator part B has a first electrode layer 33 (individual electrode) located almost directly above the pressure chamber 32. The ink flow path member C is connected to the common liquid chamber 35 shared between the pressure chambers 32 of the plurality of ink ejection elements 202 arranged in the ink supply direction, and the common liquid chamber 35 is communicated with the pressure chamber 32. A supply port 36 for supplying the ink in the common liquid chamber 35 to the pressure chamber 32 and an ink flow path 37 for discharging the ink in the pressure chamber 32 are formed. Further, D is a nozzle plate, and a nozzle hole 38 (diameter 30 μm) communicating with the ink flow path 37 is formed in the nozzle plate D. Then, the pressure chamber member A, the actuator part B, the ink flow path member C, and the nozzle plate D are bonded with an adhesive to constitute the ink ejection element 202.
[0197]
  In the present embodiment, the pressure chamber member A, the actuator portion B (excluding the first electrode layer 33 and the piezoelectric layer 41 (see FIG. 12)), the ink flow path member C, and the nozzle plate D are used for discharging all ink. A portion integrally formed over the element 202 and including one pressure chamber 32, a nozzle hole 38 corresponding to the pressure chamber 32, the first electrode layer 33, and the piezoelectric layer 41. Is the ink ejection element 202. In addition, each ink discharge element 202 may be formed separately and these may be combined and combined. Further, the inkjet head 201 does not need to be composed of a plurality of ink ejection elements 202, and may be composed of a single ink ejection element 202.
[0198]
  The drive power supply element 203 is connected to each first electrode layer 33 of the actuator part B of the plurality of ink ejection elements 202 via bonding wires, and each first electrode layer 33 is connected from the drive power supply element 203. To supply voltage.
[0199]
  Next, the configuration of the actuator part B will be described with reference to FIG. 12 is a cross-sectional view taken along line XII-XII of the actuator portion B of the ink ejection element 202 shown in FIG. As shown in FIG. 12, the actuator portion B includes a first electrode layer 33 positioned substantially directly above each pressure chamber 32 as described above, and on each first electrode layer 33 (in FIG. And a second electrode layer 42 (provided on the piezoelectric layer 41 (on the same side) and common to all the piezoelectric layers 41 (all ink ejection elements 202)). Common electrode) and a vibration layer 43 which is provided on the entire second electrode layer 42 (on the same lower side) and vibrates by being displaced in the layer thickness direction by the piezoelectric effect of the piezoelectric layer 41. Similarly to the second electrode layer 42, the vibrating body layer 43 is also shared between the pressure chambers 32 of the respective ink ejection elements 202 (is integrally formed across all the ink ejection elements 202).
[0200]
  The first electrode layer 33, the piezoelectric layer 41, and the second electrode layer 42 constitute a piezoelectric element in which these are sequentially laminated. Further, the vibration layer 43 is provided on the surface of the piezoelectric element on the second electrode layer 42 side.
[0201]
  As in the first embodiment, the first electrode layer 33 is formed of an iridium (Ir) film having a thickness of 0.10 μm and containing 6 mol% of cobalt (Co), and serves as an electrode. Thus, an electrode and crystal orientation control layer that also serves to control the crystal orientation of the piezoelectric layer 41 is configured.
[0202]
  The piezoelectric layer 41 is made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane as in the first embodiment, and in this embodiment also has a thickness of 2.50 μm. Pb (Zr_0.53Ti_0.47) O₃It consists of a PZT film denoted by.
[0203]
  The second electrode layer 42 is made of a platinum thin film (however, the film thickness is 0.10 μm) as in the first embodiment.
[0204]
  The vibration layer 43 is made of a chromium (Cr) film having a thickness of 3.5 μm. The material of the vibration layer 43 is not limited to Cr, but is nickel, aluminum, tantalum, tungsten, silicon, or an oxide or nitride thereof (for example, silicon dioxide, aluminum oxide, zirconium oxide, silicon nitride) or the like. Also good. Moreover, the film thickness of the vibration layer 43 should just be 2-5 micrometers.
[0205]
  On the second electrode layer 42, an electric circuit made of polyimide resin is provided around the laminated film of the first electrode layer 33 and the piezoelectric layer 41 so that the upper surface is the same as the height of the first electrode layer 33. An insulating organic film 44 is provided. On the upper surface of the electrically insulating organic film 44, a lead electrode-shaped gold thin film (film thickness of 0.10 μm) extending from the first electrode layer 33 is formed. ing.
[0206]
  Next, a method for manufacturing the inkjet head 201 will be described with reference to FIG.
[0207]
  That is, first, as shown in FIG. 13A, a first electrode is formed on a silicon substrate 51 in the same manner as in the first embodiment using a silicon substrate 51 having a length of 20 mm, a width of 20 mm, and a thickness of 0.3 mm. The layer 33, the piezoelectric layer 41, and the second electrode layer 42 are sequentially stacked to obtain the structure 54. Note that an adhesion layer made of one kind selected from the group of titanium, tantalum, and molybdenum may be formed between the silicon substrate 51 and the first electrode layer 33 as in the first embodiment.
[0208]
  Subsequently, as shown in FIG. 13B, the vibration layer 43 made of a chromium (Cr) film (thickness: 3.5 μm) is formed on the second electrode layer 42 of the structure 54 by RF sputtering at room temperature. Form.
[0209]
  Next, as shown in FIG. 13C, the structure 54 on which the vibration layer 43 is formed is joined to the pressure chamber member A using an adhesive (acrylic resin) 55. At this time, the pressure chamber member A in which the pressure chamber opening 31 is formed in advance is joined to the surface of the vibration layer 43 opposite to the second electrode layer 42.
[0210]
  Thereafter, as shown in FIG. 13 (d), the silicon substrate 51 is made SF using a plasma reaction etching apparatus.₆It is removed by dry etching using a gas. In the case where an adhesion layer is formed between the silicon substrate 51 and the first electrode layer 33, the adhesion layer is also removed.
[0211]
  Next, as shown in FIG. 13E, the laminated film of the first electrode layer 33 and the piezoelectric layer 41 is patterned in an elliptical pattern (size: an elliptical shape having a minor axis of 180 μm and a major axis of 380 μm). In order to perform the annealing, a photoresist resin film 57 is applied to the non-etched portion on the first electrode layer 33.
[0212]
  And as shown in FIG.13 (f), the 1st electrode layer 33 and the piezoelectric material layer 41 are patterned and individualized by performing an etching process using weak hydrofluoric acid, Then, FIG. As shown in g), the photoresist resin film 57 is removed by treatment with a resist stripper.
[0213]
  Subsequently, as shown in FIG. 13H, an electrically insulating organic film 44 made of polyimide resin is formed on the second electrode layer 42 exposed by the above patterning by a printing method. As shown in i), a lead wire-shaped lead electrode film 45 made of a gold thin film is formed on the upper surface of the electrically insulating organic film 44 by DC sputtering, whereby the actuator part B is completed.
[0214]
  On the other hand, although not shown, the ink flow path member C in which the common liquid chamber 35, the supply port 36, and the ink flow path 37 are formed in advance and the nozzle plate D in which the nozzle holes 38 are formed in advance are bonded using an adhesive. Keep it. Then, alignment adjustment of the pressure chamber member A joined to the completed actuator part B and the ink flow path member C to which the nozzle plate D is bonded is performed, and both are bonded by an adhesive. Thus, the inkjet head 201 is completed.
[0215]
  The first electrode layer 33, the piezoelectric layer 41, and the second electrode layer 42 are made of any of the materials described in the first embodiment. be able to. Further, the thickness of each layer may be in the range described in the first embodiment.
[0216]
  In the inkjet head 201 configured as described above, a voltage is supplied from the drive power supply element 203 to each of the first electrode layers 33 of the plurality of ink ejection elements 202 via the bonding wires, and the piezoelectric effect of the piezoelectric layer 41 is achieved. As a result, the vibration layer 43 joined to the second electrode layer 42 that is a common electrode is displaced and vibrated, so that the ink in the common liquid chamber 35 passes through the supply port 36, the pressure chamber 32, and the ink flow path 37. It is discharged from the nozzle hole 38. In this case, in the ink jet head 201, the piezoelectric layer 41 constituting the actuator part B of the ink ejection element 202 has a crystal orientation aligned on the (001) plane, and the piezoelectric displacement characteristics have a large value and are aligned. Therefore, a large piezoelectric displacement (displacement amount) can be obtained, and the variation in the piezoelectric displacement characteristics among the plurality of ink ejection elements 202 is reduced. Since the piezoelectric displacement is large, the ink ejection capability is high, and a margin can be taken in the adjustment range of the power supply voltage, so that the variation in ejection of individual inks of the plurality of ink ejection elements 202 is reduced. It can be easily controlled.
[0217]
  Here, the inkjet head 201 having 250 ink ejection elements 202 having the same shape is actually manufactured by the above manufacturing method, and the two electrode layers 33 and 42 sandwiching the piezoelectric layer 41 are applied with 0V to −10V. When a sine waveform voltage (200 Hz) was applied and the variation in vibration amplitude in the layer thickness direction of the vibration layer 43 was measured, it was found that the variation σ was as small as 1.5%.
[0218]
  (Embodiment 4)
  FIG. 14 shows an actuator portion B of an ink ejection element 202 in another inkjet head 201 according to an embodiment of the present invention (note that the same parts as those in FIG. ), As shown in FIG. 12 (Embodiment 3), an orientation control layer 46 is disposed between the first electrode layer 33 and the piezoelectric layer 41 as in Embodiment 2 above. Other configurations are the same as those shown in FIG.
[0219]
  In other words, in this embodiment, the actuator part B is provided on the first electrode layer 33 that is positioned almost directly above each pressure chamber 32 and on each first electrode layer 33 (lower side in FIG. 14). Orientation control layer 46, piezoelectric layer 41 provided on the orientation control layer 46 (on the lower side), and second electrode layer 42 provided on the piezoelectric layer 41 (on the lower side). And a vibrating layer 43 that is provided on the entire second electrode layer 42 (on the lower side) and vibrates by being displaced in the layer thickness direction by the piezoelectric effect of the piezoelectric layer 41.
[0220]
  The first electrode layer 33, the orientation control layer 46, the piezoelectric layer 41, and the second electrode layer 42 constitute a piezoelectric element in which these are sequentially laminated. Further, the vibration layer 43 is provided on the surface of the piezoelectric element on the second electrode layer 42 side.
[0221]
  As in the second embodiment, the first electrode layer 33 is formed of an iridium (Ir) film having a thickness of 0.22 μm and containing 1 mol% of cobalt (Co). In addition to the role as an electrode, An electrode and crystal orientation control layer that also serves to control the crystal orientation of the piezoelectric layer 41 is configured.
[0222]
  The orientation control layer 46 is made of a perovskite oxide preferentially oriented in a cubic or tetragonal (100) plane or (001) plane, as in the second embodiment. A lead lanthanum titanate film having a thickness of 0.02 μm (composition ratio Pb: La: Ti = 1.12: 0.08: 1.00).
[0223]
  The piezoelectric layer 41 is made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane, as in the second embodiment, and also has a thickness of 2.50 μm in this embodiment. Pb (Zr_0.53Ti_0.47) O₃It consists of a PZT film denoted by.
[0224]
  The second electrode layer 42 is made of a platinum thin film (thickness is 0.10 μm) as in the second embodiment. .
[0225]
  The vibration layer 43 is made of a chromium film having a thickness of 3.5 μm, as in the third embodiment.
[0226]
  On the second electrode layer 42, an electric circuit made of polyimide resin is provided around the laminated film of the first electrode layer 33 and the piezoelectric layer 41 so that the upper surface is the same as the height of the first electrode layer 33. An insulating organic film 44 is provided. On the upper surface of the electrically insulating organic film 44, a lead electrode-shaped gold thin film (film thickness of 0.10 μm) extending from the first electrode layer 33 is formed. ing.
[0227]
  Next, a method for manufacturing the inkjet head 201 will be described with reference to FIG.
[0228]
  That is, first, using a silicon substrate 51 having a length of 20 mm, a width of 20 mm, and a thickness of 0.3 mm, the first electrode layer 33 and the orientation control layer 46 are formed on the silicon substrate 51 as in the second embodiment (or 3). Then, the piezoelectric layer 41 and the second electrode layer 42 are sequentially laminated to obtain a structure 54 (see FIG. 15A). As described in the third embodiment, an adhesion layer made of one selected from the group of titanium, tantalum, and molybdenum may be formed between the silicon substrate 51 and the first electrode layer 33.
[0229]
  Subsequently, as in the third embodiment, a vibrating layer 43 made of a chromium film (thickness: 3.5 μm) is formed on the second electrode layer 42 of the structure 54 by RF sputtering at room temperature (see FIG. 15 (b)), and subsequently, the structure 54 in which the vibration layer 43 is formed is bonded to the pressure chamber member A using the adhesive 55 (see FIG. 15C).
[0230]
  Thereafter, similarly to the third embodiment, the silicon substrate 51 is removed by dry etching (see FIG. 15D). In the case where an adhesion layer is formed between the silicon substrate 51 and the first electrode layer 33, the adhesion layer is also removed.
[0231]
  Next, in the same manner as in the third embodiment, in order to pattern the laminated film of the first electrode layer 33, the orientation control layer 46, and the piezoelectric layer 41, the non-etched portion on the first electrode layer 33 is A photoresist resin film 57 is applied (see FIG. 15E), and then an etching process is performed to pattern and individualize the first electrode layer 33, the orientation control layer 46, and the piezoelectric layer 41 ( Thereafter, the photoresist resin film 57 is removed by treatment with a resist stripper (see FIG. 15G).
[0232]
  Subsequently, as in the third embodiment, an electrically insulating organic film 44 is formed on the second electrode layer 42 exposed by the above patterning (see FIG. 15H). An extraction electrode film 45 is formed on the upper surface of the film 44 (see FIG. 15I), whereby the actuator portion B is completed.
[0233]
  On the other hand, as in the third embodiment, the ink channel member C in which the common liquid chamber 35, the supply port 36, and the ink channel 37 are previously formed and the nozzle plate D in which the nozzle hole 38 is previously formed are used with an adhesive. The pressure chamber member A joined to the completed actuator portion B and the ink flow path member C to which the nozzle plate D is adhered are adjusted, and both are adhered by an adhesive. Thus, the inkjet head 201 is completed.
[0234]
  The first electrode layer 33, the orientation control layer 46, the piezoelectric layer 41, and the second electrode layer 42 may be any material described in the second embodiment, and the vibration layer 43 Any of the materials described in Embodiment 3 may be used. Further, the thickness of each of these layers may be in the range described in the second and third embodiments.
[0235]
  Also in the inkjet head 201 configured as described above, as in the third embodiment, the piezoelectric layer 41 constituting the actuator portion B has a crystal orientation aligned on the (001) plane, Since the displacement characteristics are large and uniform, it is possible to obtain a large piezoelectric displacement (displacement amount), and the variation in the piezoelectric displacement characteristics among the plurality of ink ejection elements 202 is reduced. Since the piezoelectric displacement is large, the ink ejection capability is high, and a margin can be taken in the adjustment range of the power supply voltage, so that the variation in ejection of individual inks of the plurality of ink ejection elements 202 is reduced. It can be easily controlled.
[0236]
  Here, the ink jet head 201 having 250 ink ejection elements 202 having the same shape is actually manufactured by the above manufacturing method, and the vibration amplitude variation in the layer thickness direction of the vibration layer 43 is the same as in the third embodiment. As a result, the variation σ was found to be extremely small at 1.2%.
[0237]
  (Embodiment 5)
  FIG. 16 shows an actuator portion B of an ink ejection element 202 in still another inkjet head 201 according to the embodiment of the present invention. In this embodiment, a pressure chamber opening 71 is formed by etching a substrate used to form a laminated film (in this embodiment, a pressure chamber substrate 70 (the same applies to the next embodiment 6)). Thus, the pressure chamber member is the same as in the third and fourth embodiments, and the point that the pressure chamber substrate 70 (pressure chamber member) and the actuator portion B are integrated thereby differs from the third and fourth embodiments.
[0238]
  An ink discharge element having a shape similar to that of FIG. 11 is obtained by adhering an ink flow path member and a nozzle plate similar to those in the third and fourth embodiments to the pressure chamber substrate 70 and the actuator portion B integrated. 202 is obtained.
[0239]
  That is, in this embodiment, the vibration layer 65 made of amorphous aluminum oxide and having a thickness of 2.50 μm is provided on the pressure chamber substrate 70 in which the pressure chamber opening 71 is formed. A first electrode layer 61 (common electrode) made of an iridium film containing cobalt (thickness: 0.10 μm) is provided thereon, and a PZT thin film (thickness: 2.50 μm) is formed on the first electrode layer 61. A piezoelectric layer 62 is provided, and on the piezoelectric layer 62, a platinum thin film (thickness: 0.10 μm) is formed and is individually separated into an elliptical shape as in the first electrode layer 33 in the third and fourth embodiments. A second electrode layer 63 (individual electrode) is provided. The first electrode layer 61, the piezoelectric layer 62, and the second electrode layer 63 constitute a piezoelectric element in which these are sequentially laminated. Further, the vibration layer 65 is provided on the surface of the piezoelectric element on the first electrode layer 61 side. In addition, an adhesion layer that improves adhesion between the vibration layer 65 and the first electrode layer 61 may be provided between the vibration layer 65 and the first electrode layer 61. This adhesion layer may also be made of one selected from the group consisting of titanium, tantalum and molybdenum.
[0240]
  The piezoelectric layer 62 and the second electrode layer 63 are formed only on the vibration chamber 65 and the first electrode layer above the portion of the pressure chamber substrate 70 where the pressure chamber opening 71 is formed (the space from which silicon is removed). The portions around the piezoelectric layer 62 and the second electrode layer 63 on the first electrode layer 61 are the same as those in the third and fourth embodiments. Similarly, it is covered with an electrically insulating organic film 64 made of polyimide resin. The individualized second electrode layer 63 is provided with a lead electrode film 75 of a gold thin film (film thickness: 0.1 μm).
[0241]
  Next, a method for manufacturing the ink jet head will be described with reference to FIG.
[0242]
  That is, as shown in FIG. 17A, the vibrating layer 65, the first electrode layer 61, the piezoelectric layer 62, and the second electrode are formed on the surface of the pressure chamber substrate 70 made of silicon having a thickness of 0.3 mm. The layer 63 is sequentially deposited by sputtering.
[0243]
  The vibration layer 65 is formed by using an RF magnetron sputtering apparatus, a substrate temperature of 400 ° C., an aluminum oxide target, a sputtering gas using a mixed gas of argon and oxygen of 14: 1, and a gas pressure of 0.1. It can be obtained by sputtering for 3 hours at 2 Pa and sputtering power of 700 W. The first electrode layer 61, the piezoelectric layer 62, and the second electrode layer 63 are obtained in the same manner as described in the first embodiment.
[0244]
  Subsequently, as shown in FIG. 17B, a pressure chamber opening 71 (size: minor axis is 200 μm, on the surface of the pressure chamber substrate 70 opposite to the formation surface of the laminated film including the above layers, In order to form an elliptical shape having a long axis of 400 μm, a photoresist resin film 66 is applied so as to cover other portions.
[0245]
  Then, as shown in FIG. 17C, using a plasma reaction etching apparatus, dry etching is performed using SF 6 gas to form a pressure chamber opening 71 in the pressure chamber substrate 70.
[0246]
  Next, as shown in FIG. 17 (d), the photoresist resin film 66 is removed, and then, as shown in FIG. 17 (e), the second electrode layer 63 (true pressure chamber opening 71) is removed. A photoresist resin film 67 is formed in an elliptic pattern (size: elliptical shape with a minor axis of 180 μm and a major axis of 380 μm) on the upper part).
[0247]
  Next, as shown in FIG. 17F, a parallel plate type plasma reaction etching apparatus is used, and dry etching is performed using a mixed gas of argon gas and CF 4 gas, so that the same shape as the photoresist resin film 67 is obtained. A laminated film of the piezoelectric layer 62 and the second electrode layer 63 that is individualized into the elliptical pattern is obtained. In this dry etching, the first electrode layer 61 can be used as an etching end point because the etching rate is low unlike the other layers.
[0248]
  Subsequently, as shown in FIG. 17 (g), the elliptical photoresist resin film 67 is removed, and a polyimide resin coating film is formed around the individual laminated film by a printing method. The coating film is cured at 180 ° C. to form an electrically insulating organic film 64 made of polyimide resin.
[0249]
  Next, as shown in FIG. 17 (h), a lead thin film (thickness: 0.1 μm) is drawn by sputtering so as to overlap the electrically insulating organic film 64 with a part of the second electrode layer 63. The electrode 75 is formed, whereby the actuator part B in which the pressure chamber substrate 70 is integrated is completed.
[0250]
  Then, the ink flow path component and the nozzle plate are bonded to the pressure chamber substrate 70 (pressure chamber member) in the same manner as in the third and fourth embodiments, thereby completing the ink jet head 201.
[0251]
  Also in this embodiment, the crystal orientation of the piezoelectric layer 62 is aligned with the (001) plane as in the third embodiment, and this enables a large piezoelectric displacement (displacement amount) to be obtained. In addition, variations in piezoelectric displacement characteristics among a plurality of ink ejection elements 202 can be suppressed.
[0252]
  Any material may be used for the first electrode layer 61, the piezoelectric layer 62, and the second electrode layer 63 as long as they are described in the first embodiment, and the vibration layer 65 is used in the above-described embodiment. Any material described in 3 may be used. Further, the thicknesses of these layers may be in the ranges described in the first and third embodiments.
[0253]
  Here, the inkjet head 201 having 150 ink ejection elements 202 having the same shape is actually manufactured by the manufacturing method described above, and the variation in the vibration amplitude in the layer thickness direction of the vibration layer 65 is the same as in the third embodiment. As a result, it was found that the variation σ was extremely small at 2.0%.
[0254]
  (Embodiment 6)
  18 shows an actuator portion B of an ink ejection element 202 in still another inkjet head 201 according to the embodiment of the present invention (note that the same parts as those in FIG. In contrast to the embodiment shown in FIG. 16 (Embodiment 5), an orientation control layer 69 is disposed between the first electrode layer 61 and the piezoelectric layer 62 as in Embodiments 2 and 4 above. The other structure is the same as that shown in FIG.
[0255]
  That is, in this embodiment, the vibration layer 65 is provided on the pressure chamber substrate 70 in which the pressure chamber opening 71 is formed, and the first electrode layer 61 is provided on the vibration layer 65. An orientation control layer 69 is provided on the electrode layer 61, a piezoelectric layer 62 is provided on the orientation control layer 69, and a second electrode layer 63 is provided on the piezoelectric layer 62. The first electrode layer 61, the orientation control layer 69, the piezoelectric layer 62, and the second electrode layer 63 constitute a piezoelectric element in which these are sequentially laminated. Further, the vibration layer 65 is provided on the surface of the piezoelectric element on the first electrode layer 61 side. In addition, an adhesion layer that improves adhesion between the vibration layer 65 and the first electrode layer 61 may be provided between the vibration layer 65 and the first electrode layer 61. This adhesion layer may also be made of one selected from the group consisting of titanium, tantalum and molybdenum.
[0256]
  Similar to the piezoelectric layer 62 and the second electrode layer 63, the orientation control layer 69 is also individualized so as to exist only above the portion of the pressure chamber substrate 70 where the pressure chamber opening 71 is formed. ing.
[0257]
  Next, a method for manufacturing the ink jet head will be described with reference to FIG.
[0258]
  That is, as in the second embodiment (or 5), the vibration layer 65, the first electrode layer 61, the orientation control layer 69, and the piezoelectric layer are formed on the surface of the pressure chamber substrate 70 made of silicon having a thickness of 0.3 mm. 62 and the second electrode layer 63 are sequentially deposited by sputtering (see FIG. 19A).
[0259]
  The vibration layer 65 is obtained in the same manner as the method described in the fifth embodiment. The first electrode layer 61, the orientation control layer 69, the piezoelectric layer 62, and the second electrode layer 63 are obtained in the same manner as described in the second embodiment.
[0260]
  Subsequently, in the same manner as in the fifth embodiment, the pressure chamber substrate 70 is covered with the other portion to form the pressure chamber opening 71 on the surface of the pressure chamber substrate 70 opposite to the formation surface of the laminated film composed of the layers. In this manner, a photoresist resin film 66 is applied in a pattern (see FIG. 19B), and then dry etching is performed to form a pressure chamber opening 71 in the pressure chamber substrate 70 (see FIG. 19C).
[0261]
  Then, as in the fifth embodiment, the photoresist resin film 66 is removed (see FIG. 19D), and then on the second electrode layer 63 (a portion directly above the pressure chamber opening 71). Next, a photoresist resin film 67 is formed in an elliptical pattern (see FIG. 19E).
[0262]
  Next, as in the fifth embodiment, dry etching is performed, and the orientation control layer 69, the piezoelectric layer 62, and the second electrode layer are individually separated into an elliptic pattern having the same shape as the photoresist resin film 67. 63 is obtained (see FIG. 19F).
[0263]
  Subsequently, as in the fifth embodiment, the oval photoresist resin film 67 is removed, and a polyimide resin coating film is formed around the individual laminated film. Curing is performed at a temperature to form an electrically insulating organic film 64 made of polyimide resin (see FIG. 19G), and then an extraction electrode 75 is formed on the electrically insulating organic film 64 (see FIG. 19H). Thus, the actuator part B in which the pressure chamber substrate 70 is integrated is completed.
[0264]
  Then, the ink flow path component and the nozzle plate are bonded to the pressure chamber substrate 70 (pressure chamber member) in the same manner as in the fifth embodiment, and thus the ink jet head 201 is completed.
[0265]
  Also in this embodiment, the crystal orientation of the piezoelectric layer 62 is aligned with the (001) plane, as in the fourth embodiment, so that a large piezoelectric displacement (displacement amount) can be obtained. In addition, variations in piezoelectric displacement characteristics among a plurality of ink ejection elements 202 can be suppressed.
[0266]
  The first electrode layer 61, the orientation control layer 69, the piezoelectric layer 62, and the second electrode layer 63 may be any material described in the second embodiment, and the vibration layer 65 may be used. Any of the materials described in Embodiment 3 may be used. Further, the thickness of each of these layers may be in the range described in the second and third embodiments.
[0267]
  Here, the inkjet head 201 having 150 ink ejection elements 202 having the same shape is actually manufactured by the manufacturing method described above, and the variation in the vibration amplitude in the layer thickness direction of the vibration layer 65 is the same as in the third embodiment. As a result, the variation σ was found to be extremely small at 2.3%.
[0268]
  (Embodiment 7)
  FIG. 20 shows an ink jet recording apparatus 81 according to an embodiment of the present invention, and this ink jet recording apparatus 81 includes an ink jet head 201 similar to any one of the above third to sixth embodiments. In the ink jet head 201, the ink in the pressure chamber is transferred from the nozzle hole (nozzle hole 38 described in the third embodiment) provided to communicate with the pressure chamber (the pressure chamber 32 described in the third embodiment). Recording is performed by ejecting and landing on (recording paper or the like).
[0269]
  The inkjet head 201 is mounted on a carriage 84 provided on a carriage shaft 83 extending in the main scanning direction x, and reciprocates in the main scanning direction x as the carriage 84 reciprocates along the carriage shaft 83. It is configured to move. Thus, the carriage 83 constitutes a relative movement unit that relatively moves the inkjet head 201 and the recording medium 82 in the main scanning direction x.
[0270]
  The ink jet recording apparatus 81 includes a plurality of rollers 85 that move the recording medium 82 in the sub scanning direction y substantially perpendicular to the main scanning direction x (width direction) of the ink jet head 201. Thus, the plurality of rollers 85 constitute a relative movement unit that relatively moves the inkjet head 201 and the recording medium 82 in the sub-scanning direction y. In FIG. 20, z is the vertical direction.
[0271]
  When the ink jet head 201 is moved in the main scanning direction x by the carriage 84, ink is ejected from the nozzle holes of the ink jet head 201 to the recording medium 82. The recording medium 82 is moved by a predetermined amount to perform the next one-scan recording.
[0272]
  As described above, the ink jet recording apparatus 81 uses the ink jet head 201 according to any one of the above embodiments 3 to 6 that can easily control the ink discharge variation among the plurality of ink discharge elements 202. With this configuration, it is possible to reduce the variation in recording on the recording medium 82 such as paper, so that the reliability can be improved.
[0273]
  (Embodiment 8)
  21 and 22 show an angular velocity sensor according to an embodiment of the present invention. This angular velocity sensor is of a tuning fork type and is preferably used for a navigation device or the like mounted on a vehicle.
[0274]
  The angular velocity sensor includes a substrate 500 made of a silicon wafer having a thickness of 0.3 mm (a glass substrate, a metal substrate, or a ceramic substrate may be used). The substrate 500 includes a fixed portion 500a and a pair of vibrating portions 500b extending from the fixed portion 500a in a predetermined direction (a direction in which the rotation center axis of the detected angular velocity extends; in the present embodiment, the y direction shown in FIG. 21). have. The fixed portion 500a and the pair of vibrating portions 500b have a tuning fork shape when viewed from the thickness direction of the substrate 500 (z direction shown in FIG. 21), and the pair of vibrating portions 500b correspond to the arm portions of the tuning fork. , And extend in parallel with each other in a state of being arranged in the width direction of the vibration part 500b.
[0275]
  A first electrode layer 503, an orientation control layer 504, a piezoelectric layer 505, and a second electrode layer 506 are sequentially stacked on the vibration part 500 b and the vibration part side portion of the fixed part 500 a of the substrate 500. ing. In this angular velocity sensor as well, it is preferable to provide an adhesion layer between the substrate 500 and the first electrode layer 503, as in the piezoelectric element in the modification of the second embodiment.
[0276]
  The constituent materials and thicknesses of the first electrode layer 503, the orientation control layer 504, the piezoelectric layer 505, and the second electrode layer 506 are the same as those of the first electrode layer 2 and the orientation control layer 11 described in the second embodiment. The same applies to the piezoelectric layer 3 and the second electrode layer 4. The structures of the orientation control layer 504 and the piezoelectric layer 505 are the same as those of the orientation control layer 15 and the piezoelectric layer 16, respectively, and the vicinity of the surface of the orientation control layer 504 on the first electrode layer 503 side is (100 ) Plane or (001) plane oriented region exists on the metal (such as cobalt) located on the surface portion of the first electrode layer 503 on the orientation control layer 504 side, and the region in a cross section perpendicular to the layer thickness direction. Has a structure in which the area increases from the first electrode layer 503 side toward the piezoelectric layer 505 side.
[0277]
  The second electrode layer 506 includes two drive electrodes 507 for vibrating the vibration part 500b in the width direction of the vibration part 500b (the x direction shown in FIG. 21) on each vibration part 500b, and the vibration. It is patterned into one detection electrode 508 for detecting deformation (deflection) in the thickness direction (z direction) of the portion 500b.
[0278]
  The two drive electrodes 507 are provided over the entire length direction (y direction) of the vibration part 500b on both ends in the width direction (x direction) of the vibration part 500b, and the fixing part 500a of each drive electrode 507 is provided. The end on the side is located on the fixed portion 500a and constitutes a connection terminal 507a. Note that only one drive electrode 507 may be provided on one end in the width direction of each vibration part 500b.
[0279]
  On the other hand, the detection electrode 508 is provided over the entire length direction of the vibration part 500b on the central part in the width direction of the vibration part 500b, and, similar to the drive electrode 507, the detection electrode 508 is fixed to the fixed part 500a side. These end portions are located on the fixed portion 500a to constitute the connection terminal 508a. A plurality of detection electrodes 508 may be provided on each vibration part 500b.
[0280]
  The first electrode layer 503 has a connection terminal 503a that protrudes on the opposite side of the vibration part 500b at the center position between the pair of vibration parts 500b on the fixed part 500a.
[0281]
  Between the first electrode layer 503 and the two drive electrodes 507 on each vibration part 500b, a frequency that resonates with the natural vibration of the vibration part 500b so that the vibration part 500b vibrates in the width direction. The voltage is applied. That is, a ground voltage is applied to the first electrode layer 503, while voltages having opposite signs to each other are applied to the two drive electrodes 507, whereby one end portion in the width direction of each vibration unit 500b. When the side extends, the other end side contracts and the vibrating part 500b is deformed to the other end side. On the other hand, when the width direction one end part side of each vibration part 500b contracts, the other end part side is extended, and the vibration part 500b is deformed to the one end part side. By repeating this operation alternately, the vibration part 500b vibrates in the width direction. Note that the vibrating section 500b can be vibrated in the width direction only by applying a voltage to one of the two drive electrodes 500b on each vibrating section 500b. The pair of vibration parts 500b are deformed in opposite directions in the width direction of each vibration part 500b, and are centered between the pair of vibration parts 500b and extend along the length line of the vibration part 500b. Oscillate symmetrically.
[0282]
  In the angular velocity sensor having the above configuration, when an angular velocity ω is applied around the center line L when the pair of vibrating portions 500b are vibrated symmetrically with respect to the center line L in the width direction (x direction), 2 The vibrating portion 500b is bent and deformed in the thickness direction (z direction) by the Coriolis force (the pair of vibrating portions 500b bend in the same direction in the opposite directions), thereby causing the piezoelectric layer 505 to bend. A voltage corresponding to the magnitude of the Coriolis force is generated between the first electrode layer 503 and the detection electrode 508. The angular velocity ω can be detected from the magnitude of this voltage (Coriolis force).
[0283]
  That is, the Coriolis force Fc is expressed as follows: v is the speed in the width direction of each vibration part 500b and m is the mass of each vibration part 500b.
  Fc = 2mvω
Therefore, the value of the angular velocity ω is known from the Coriolis force Fc.
[0284]
  Next, a method for manufacturing the angular velocity sensor will be described with reference to FIGS.
[0285]
  That is, as shown in FIG. 23A, a substrate 500 made of a φ4 inch silicon wafer having a thickness of 0.3 mm (see FIG. 24 for a plan view) is prepared. As shown in FIG. Further, the first electrode layer 503 is formed by a sputtering method under the same conditions as in the second embodiment.
[0286]
  Subsequently, as shown in FIG. 23C, an orientation control layer 504 is formed on the first electrode layer 503 by a sputtering method under the same conditions as in the second embodiment. As described in Embodiment 2 above, in the vicinity of the surface of the orientation control layer 504 on the first electrode layer 503 side, a region of (100) plane or (001) plane orientation exists on the titanium, and the layer thickness direction The area of the region in a cross section perpendicular to the first electrode layer 503 increases from the first electrode layer 503 side toward the upper side.
[0287]
  Next, as shown in FIG. 23D, a piezoelectric layer 505 is formed on the orientation control layer 504 by sputtering under the same conditions as in the second embodiment. As described in Embodiment 2 above, this piezoelectric layer 505 is rhombohedral and has a (001) plane orientation of 90% or more.
[0288]
  Subsequently, as shown in FIG. 23E, the second electrode layer 506 is formed on the piezoelectric layer 505 by the sputtering method under the same conditions as in the second embodiment.
[0289]
  Next, as shown in FIG. 23F and FIG. 24, the second electrode layer 506 is patterned to form the drive electrode 507 and the detection electrode 508. That is, a photosensitive resin is applied on the second electrode layer 506, the patterns of the drive electrode 507 and the detection electrode 508 are exposed to this photosensitive resin, and then the photosensitive resin in the unexposed portion is removed. The second electrode layer 506 in the portion where the photosensitive resin is removed is removed by etching, and then the photosensitive resin on the drive electrode 507 and the detection electrode 508 is removed.
[0290]
  After patterning the second electrode layer 506, the piezoelectric layer 505, the orientation control layer 504, and the first electrode layer 503 are patterned by the same process, and the substrate 500 is patterned to fix the fixed portion. 500a and the vibration part 500b are formed. Thus, the above angular velocity sensor is completed.
[0291]
  The film forming method for each layer is not limited to the sputtering method, but may be any film forming method (for example, CVD method) that directly forms a crystalline thin film without a crystallization step by heat treatment.
[0292]
  Here, a conventional angular velocity sensor will be described with reference to FIGS. 25 and 26. FIG.
[0293]
  This conventional angular velocity sensor includes a piezoelectric body 600 made of quartz having a thickness of 0.3 mm. The piezoelectric body 600 includes a fixed portion 600a and a fixed portion 600a, like the substrate 500 of the angular velocity sensor according to the present embodiment. It has a pair of vibrating parts 600b extending in parallel to one side (y direction shown in FIG. 25). Drive electrodes 603 for vibrating the vibrating portion 600b in the width direction (x direction shown in FIG. 25) are provided on both surfaces of the vibrating portion 600b facing each other in the thickness direction (z direction shown in FIG. 25). One detection electrode 607 for detecting deformation in the thickness direction of the vibration part 600b is provided on each side surface of each vibration part 600b.
[0294]
  In the conventional angular velocity sensor, a voltage having a frequency that resonates with the natural vibration of the vibrating portion 600b is applied between the two drive electrodes 603 in each vibrating portion 600b, and similarly to the angular velocity sensor according to the present embodiment. The pair of vibration parts 600b are vibrated symmetrically with respect to the center line L at the center between the pair of vibration parts 600b in the width direction (x direction). At this time, when an angular velocity ω is applied around the center line L, the pair of vibration parts 600b is deformed by bending in the thickness direction (z direction) by Coriolis force, and between the two detection electrodes 607 in each vibration part 600b. A voltage corresponding to the magnitude of the Coriolis force is generated, and the angular velocity ω can be detected from the magnitude of this voltage (Coriolis force).
[0295]
  In the conventional angular velocity sensor, since the piezoelectric body 600 made of quartz is used, its piezoelectric constant is as low as −3 pC / N, and since the fixed portion 600a and the vibrating portion 600b are formed by machining, it is difficult to reduce the size. There is a problem that the dimensional accuracy is low.
[0296]
  On the other hand, in the angular velocity sensor according to the present embodiment, the portion for detecting the angular velocity (vibrating unit 500b) is composed of a piezoelectric element having the same configuration as that of the second embodiment. The piezoelectric constant can be increased to about 40 times that of the angular velocity sensor, and a considerable reduction in size can be achieved. Further, fine processing can be performed using a thin film forming technique, and the dimensional accuracy can be significantly improved. Furthermore, even in mass production industrially, the reproducibility of characteristics is good, there is little variation, and the withstand voltage and reliability are excellent.
[0297]
  In the angular velocity sensor according to this embodiment, the materials for the first electrode layer 503, the orientation control layer 504, the piezoelectric layer 505, and the second electrode layer 506 are the same as those described in the second embodiment. Any of them may be used. Even if the orientation control layer 504 is eliminated as in the first embodiment, a high-performance angular velocity sensor can be obtained.
[0298]
  Further, in the angular velocity sensor according to the present embodiment, only one pair of the vibrating parts 500b is provided on the substrate 500, but a plurality of sets may be provided to detect angular velocities around a plurality of axes extending in various directions. Good.
[0299]
  Furthermore, in the angular velocity sensor according to the present embodiment, the first electrode layer 503, the orientation control layer 504, the piezoelectric layer 505, and the second layer are formed on the vibration part 500 b and the fixed part 500 a of the substrate 500 on the vibration part side. The electrode layers 506 are stacked in order, but the positions where these layers are stacked may be only on the vibrating portions 500b.
[0300]
  In addition, in the above embodiment, the piezoelectric element of the present invention is applied to an ink jet head (ink jet recording apparatus) and an angular velocity sensor. In addition to this, a thin film capacitor, a charge storage capacitor of a nonvolatile memory element, and various actuators , Infrared sensor, ultrasonic sensor, pressure sensor, acceleration sensor, flow sensor, shock sensor, piezoelectric transformer, piezoelectric ignition element, piezoelectric speaker, piezoelectric microphone, piezoelectric filter, piezoelectric pickup, tuning fork oscillator, delay line, etc. Is possible. In particular, in a head support mechanism in which a head for recording or reproducing information on a disk that is rotationally driven in a disk device (used as a storage device of a computer) is provided on the substrate, the head support mechanism is provided on the substrate. The thin film piezoelectric element is suitable for a thin film piezoelectric actuator for a disk device (see, for example, Japanese Patent Application Laid-Open No. 2001-332041) in which a substrate is deformed by a thin film piezoelectric element to displace the head. That is, the thin film piezoelectric element is formed by sequentially laminating a first electrode layer, an orientation control layer, a piezoelectric layer, and a second electrode layer having the same configuration as that described in the above embodiment. Two electrode layers are bonded to the substrate.
[0301]
【The invention's effect】
  As described above, according to the present invention, the substrate also serves as the crystal orientation control layer made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese, and copper and a noble metal. 1 electrode layer, and this first electrode layerThe content of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper in the case of more than 0 and not more than 26 mol%,A piezoelectric layer made of rhombohedral or tetragonal perovskite type oxide is provided on the first electrode layer, so that a direct crystallization process by heat treatment after film formation can be achieved. For example, a piezoelectric layer in which the crystal structure and the preferential orientation plane are controlled can be formed by, for example, a sputtering method, and by this, as in the sol-gel method, by a heat treatment that causes generation of cracks and characteristic variation The crystallization step can be eliminated. As a result, it is possible to provide a piezoelectric element with excellent reproducibility, variation, and reliability of piezoelectric characteristics, and an ink jet head and an angular velocity sensor having the piezoelectric element even when industrially mass-produced. In addition, it is possible to provide an ink jet type recording apparatus with little variation in ejection performance and high reliability.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a piezoelectric element according to an embodiment of the present invention.
FIG. 2 is a process diagram showing a method for manufacturing the piezoelectric element of FIG. 1;
3 is a characteristic diagram showing the amount of displacement of the tip of the piezoelectric element when a triangular wave voltage is applied between the first electrode layer and the second electrode layer in the piezoelectric element of FIG. 1. FIG.
4 is a view corresponding to FIG. 3 in the piezoelectric element of Comparative Example 1. FIG.
FIG. 5 is a perspective view showing another piezoelectric element according to the embodiment of the present invention.
6 is a process diagram showing a method for manufacturing the piezoelectric element of FIG. 5; FIG.
7 is a perspective view showing a modification of the piezoelectric element in FIG. 5. FIG.
8 is a process chart showing a method for manufacturing the piezoelectric element of FIG. 7. FIG.
9 is a view corresponding to FIG. 3 in the piezoelectric element of FIG. 5;
FIG. 10 is a schematic view showing an inkjet head according to an embodiment of the present invention.
FIG. 11 is an exploded perspective view, partly broken away, showing an ink ejection element of the ink jet head of FIG.
12 is a cross-sectional view taken along line XII-XII in FIG.
13 is a process diagram illustrating a method of manufacturing the ink jet head of FIG. 10;
FIG. 14 is a view corresponding to FIG. 12 showing a main part (actuator part) of another inkjet head according to the embodiment of the present invention.
15 is a process diagram illustrating a method of manufacturing the ink jet head of FIG. 14;
FIG. 16 is a view corresponding to FIG. 12 showing a main part (actuator part) of still another inkjet head according to the embodiment of the present invention.
17 is a process diagram illustrating a method of manufacturing the ink jet head of FIG. 16;
FIG. 18 is a view corresponding to FIG. 12 and showing a main part (actuator part) of still another inkjet head according to the embodiment of the present invention.
19 is a process chart showing a method for manufacturing the ink jet head of FIG. 18. FIG.
FIG. 20 is a schematic perspective view showing an ink jet recording apparatus according to an embodiment of the present invention.
FIG. 21 is a schematic perspective view showing an angular velocity sensor according to an embodiment of the present invention.
22 is a cross-sectional view taken along line XXII-XXII in FIG.
23 is a process chart showing a method for manufacturing the angular velocity sensor of FIG. 21. FIG.
24 is a plan view showing a state in which the second electrode layer is patterned in the manufacturing method of the angular velocity sensor of FIG. 21. FIG.
FIG. 25 is a schematic perspective view showing a conventional angular velocity sensor using a crystal.
26 is a cross-sectional view taken along line XXVI-XXVI in FIG.
[Explanation of symbols]
  1 Substrate
  2 First electrode layer
  3 Piezoelectric layer
  4 Second electrode layer
  11 Orientation control layer
  14 Adhesive layer
  20 Piezoelectric element
  32 Pressure chamber
  33 First electrode layer (individual electrode)
  38 Nozzle holes
  41 Piezoelectric layer
  42 Second electrode layer (common electrode)
  43 Vibration layer
  46 Orientation control layer
  51 substrates
  61 1st electrode layer (common electrode)
  62 Piezoelectric layer
  63 Second electrode layer (individual electrode)
  65 Vibration layer
  69 Orientation control layer
  70 Pressure chamber substrate (pressure chamber member)
  81 Inkjet recording apparatus
  82 Recording media
  84 Carriage (relative movement means)
  201 Ink Jet Head
  500 substrates
  500a fixed part
  500b Vibration part
  503 1st electrode layer
  504 Orientation control layer
  505 Piezoelectric layer
  506 Second electrode layer
  507 Drive electrode
  508 Detection electrode
  A Pressure chamber member
  B Actuator

Claims (26)

A piezoelectric element comprising a first electrode layer, a piezoelectric layer provided on the first electrode layer, and a second electrode layer provided on the piezoelectric layer,
The first electrode layer is made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal,
The content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and not more than 26 mol%;
The piezoelectric element is made of a perovskite oxide preferentially oriented in a rhombohedral or tetragonal (001) plane. The piezoelectric element according to claim 1 , wherein
The first electrode layer is provided on the substrate,
An adhesion layer is provided between the substrate and the first electrode layer to enhance adhesion between the substrate and the first electrode layer ,
The piezoelectric element is characterized in that the substrate is made of any one of a silicon substrate, a glass substrate, a metal substrate, and a ceramic substrate . The piezoelectric element according to claim 2 , wherein
The adhesion layer is made of one selected from the group consisting of titanium, tantalum, and molybdenum. In the piezoelectric element according to any one of claims 1 to 3 ,
An orientation control layer made of a perovskite oxide preferentially oriented on a cubic or tetragonal (100) plane or (001) plane is provided between the first electrode layer and the piezoelectric layer. A piezoelectric element characterized by the above. The piezoelectric element according to claim 4 , wherein
The orientation control layer is made of lead lanthanum titanate or lead lanthanum titanate to which at least one of magnesium and manganese is added. The piezoelectric element according to claim 4 , wherein
The orientation control layer is made of a perovskite oxide containing strontium. The piezoelectric element according to claim 6 .
The orientation control layer contains a strontium titanate piezoelectric element. In the piezoelectric element according to any one of claims 1 to 7 ,
A piezoelectric element, wherein the noble metal in the first electrode layer is at least one selected from the group consisting of platinum, iridium, palladium, and ruthenium. A piezoelectric element in which a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially laminated; a vibration layer provided on a surface of the piezoelectric element on the second electrode layer side; A pressure chamber member having a pressure chamber which is bonded to a surface opposite to the piezoelectric element and contains ink, and the vibration layer is displaced in the layer thickness direction by the piezoelectric effect of the piezoelectric layer of the piezoelectric element. An inkjet head configured to eject ink in a pressure chamber,
The first electrode layer of the piezoelectric element is made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal,
The content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less;
The inkjet head according to claim 1, wherein the piezoelectric layer is made of a perovskite oxide preferentially oriented in a rhombohedral or tetragonal (001) plane. The inkjet head according to claim 9 , wherein
An orientation control layer made of a perovskite oxide preferentially oriented in a cubic or tetragonal (100) plane or (001) plane is provided between the first electrode layer and the piezoelectric layer of the piezoelectric element. An ink jet head characterized by comprising: A piezoelectric element in which a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially laminated; a vibration layer provided on a surface of the piezoelectric element on the first electrode layer side; A pressure chamber member having a pressure chamber that is bonded to a surface opposite to the piezoelectric element and that stores ink, and the vibration layer is displaced in the layer thickness direction by the piezoelectric effect of the piezoelectric layer of the piezoelectric element. An inkjet head configured to eject ink in a pressure chamber,
The first electrode layer of the piezoelectric element is made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal,
The content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and not more than 26 mol%;
The ink jet head according to claim 1, wherein the piezoelectric layer is made of a perovskite oxide preferentially oriented in a rhombohedral or tetragonal (001) plane. The inkjet head according to claim 11 , wherein
An orientation control layer made of a perovskite oxide preferentially oriented in a cubic or tetragonal (100) plane or (001) plane is provided between the first electrode layer and the piezoelectric layer of the piezoelectric element. An ink jet head characterized by comprising: A substrate having a fixed portion and at least a pair of vibrating portions extending in a predetermined direction from the fixed portion, and a first electrode layer, a piezoelectric layer, and a second electrode layer on at least each vibrating portion of the substrate Are stacked in order, and the second electrode layer on each vibration part has at least one drive electrode for vibrating the vibration part in the width direction of the vibration part, and deformation in the thickness direction of the vibration part. An angular velocity sensor patterned with at least one detection electrode for detecting
The first electrode layer is made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal,
The content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and not more than 26 mol%;
2. The angular velocity sensor according to claim 1, wherein the piezoelectric layer is made of a perovskite oxide preferentially oriented in a rhombohedral or tetragonal (001) plane. The angular velocity sensor according to claim 13 .
An orientation control layer made of a perovskite oxide preferentially oriented on a cubic or tetragonal (100) plane or (001) plane is provided between the first electrode layer and the piezoelectric layer. An angular velocity sensor. Forming a first electrode layer made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper on a substrate by a sputtering method;
Forming a piezoelectric layer made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane on the first electrode layer by sputtering;
Look including a step of forming a second electrode layer on the piezoelectric layer,
Production of a piezoelectric element, wherein the content of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and not more than 26 mol% Method. Forming a first electrode layer made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper on a substrate by a sputtering method;
Forming an orientation control layer made of a perovskite oxide preferentially oriented on a cubic or tetragonal (100) plane or (001) plane on the first electrode layer by a sputtering method;
Forming a piezoelectric layer made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane on the orientation control layer by a sputtering method;
Look including a step of forming a second electrode layer on the piezoelectric layer,
Production of a piezoelectric element, wherein the content of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less Method. A piezoelectric element in which a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially stacked; and the vibration layer is displaced in the layer thickness direction by the piezoelectric effect of the piezoelectric layer of the piezoelectric element to A method of manufacturing an ink jet head configured to eject the ink of
Forming a first electrode layer made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper on a substrate by a sputtering method;
Forming a piezoelectric layer made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane on the first electrode layer by sputtering;
Forming a second electrode layer on the piezoelectric layer;
Forming a vibration layer on the second electrode layer;
Bonding a pressure chamber member for forming a pressure chamber to a surface of the vibration layer opposite to the second electrode layer;
After the bonding step, seen including a step of removing the substrate,
Production of an ink jet head, wherein the content of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less. Method. A piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer, and a second electrode layer are sequentially stacked, and the vibration layer is displaced in the layer thickness direction by the piezoelectric effect of the piezoelectric layer of the piezoelectric element. An inkjet head manufacturing method configured to discharge ink in a pressure chamber,
Forming a first electrode layer made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper on a substrate by a sputtering method;
Forming an orientation control layer made of a perovskite oxide preferentially oriented on a cubic or tetragonal (100) plane or (001) plane on the first electrode layer by a sputtering method;
Forming a piezoelectric layer made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane on the orientation control layer by a sputtering method;
Forming a second electrode layer on the piezoelectric layer;
Forming a vibration layer on the second electrode layer;
Bonding a pressure chamber member for forming a pressure chamber to a surface of the vibration layer opposite to the second electrode layer;
After the bonding step, seen including a step of removing the substrate,
Production of an ink jet head, wherein the content of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less. Method. A piezoelectric element in which a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially stacked; and the vibration layer is displaced in the layer thickness direction by the piezoelectric effect of the piezoelectric layer of the piezoelectric element to A method of manufacturing an ink jet head configured to eject the ink of
Forming a vibration layer on a pressure chamber substrate for forming the pressure chamber;
Forming a first electrode layer made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese, and copper and a noble metal on the vibration layer by a sputtering method;
Forming a piezoelectric layer made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane on the first electrode layer by sputtering;
Forming a second electrode layer on the piezoelectric layer;
To the pressure chamber substrate, seen including a step of forming a pressure chamber,
Production of an ink jet head, wherein the content of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less. Method. A piezoelectric element in which a first electrode layer, an orientation control layer, a piezoelectric layer, and a second electrode layer are sequentially stacked, and the vibration layer is displaced in the layer thickness direction by the piezoelectric effect of the piezoelectric layer of the piezoelectric element. An inkjet head manufacturing method configured to discharge ink in a pressure chamber,
Forming a vibration layer on a pressure chamber substrate for forming the pressure chamber;
Forming a first electrode layer made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese, and copper and a noble metal on the vibration layer by a sputtering method;
Forming an orientation control layer made of a perovskite oxide preferentially oriented on a cubic or tetragonal (100) plane or (001) plane on the first electrode layer by a sputtering method;
Forming a piezoelectric layer made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane on the orientation control layer by a sputtering method;
Forming a second electrode layer on the piezoelectric layer;
To the pressure chamber substrate, seen including a step of forming a pressure chamber,
Production of an ink jet head, wherein the content of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less. Method. A substrate having a fixed portion and at least a pair of vibrating portions extending in a predetermined direction from the fixed portion, and a first electrode layer, a piezoelectric layer, and a second electrode layer on at least each vibrating portion of the substrate Are stacked in order, and the second electrode layer on each vibration part has at least one drive electrode for vibrating the vibration part in the width direction of the vibration part, and deformation in the thickness direction of the vibration part. A method of manufacturing an angular velocity sensor patterned on at least one detection electrode for detecting
Forming a first electrode layer made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper on a substrate by a sputtering method;
Forming a piezoelectric layer made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane on the first electrode layer by sputtering;
Forming a second electrode layer on the piezoelectric layer;
Patterning the second electrode layer to form the drive electrode and the detection electrode;
Patterning the piezoelectric layer and the first electrode layer;
The substrate pattern - by training saw including a step of forming the fixed portion and the vibrating portion,
The production of an angular velocity sensor, wherein the content of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less. Method. A substrate having a fixed portion and at least a pair of vibrating portions extending in a predetermined direction from the fixed portion, and a first electrode layer, an orientation control layer, a piezoelectric layer, and a first layer on at least each vibrating portion of the substrate. Two electrode layers are sequentially stacked, and the second electrode layer on each vibration part has at least one drive electrode for vibrating the vibration part in the width direction of the vibration part, and the vibration part A method of manufacturing an angular velocity sensor patterned on at least one detection electrode for detecting deformation in the thickness direction,
Forming a first electrode layer made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper on a substrate by a sputtering method;
Forming an orientation control layer made of a perovskite oxide preferentially oriented on a cubic or tetragonal (100) plane or (001) plane on the first electrode layer by a sputtering method;
Forming a piezoelectric layer made of a perovskite oxide preferentially oriented in the rhombohedral or tetragonal (001) plane on the orientation control layer by a sputtering method;
Forming a second electrode layer on the piezoelectric layer;
Patterning the second electrode layer to form the drive electrode and the detection electrode;
Patterning the piezoelectric layer, the orientation control layer and the first electrode layer;
The substrate pattern - by training saw including a step of forming the fixed portion and the vibrating portion,
The production of an angular velocity sensor, wherein the content of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less. Method. A piezoelectric element in which a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially laminated; a vibration layer provided on a surface of the piezoelectric element on the second electrode layer side; An inkjet head having a pressure chamber member bonded to a surface opposite to the piezoelectric element and having a pressure chamber for containing ink and configured to be movable relative to a recording medium, the inkjet head recording When moving relative to the medium, the vibration layer is displaced in the layer thickness direction by the piezoelectric effect of the piezoelectric layer of the piezoelectric element in the ink jet head, and the ink in the pressure chamber communicates with the pressure chamber. An ink jet recording apparatus configured to perform recording by discharging the nozzle holes to the recording medium,
The first electrode layer of the piezoelectric element in the inkjet head is made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal,
The content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and not more than 26 mol%;
2. The ink jet recording apparatus according to claim 1, wherein the piezoelectric layer is made of a perovskite oxide preferentially oriented in a rhombohedral or tetragonal (001) plane. The ink jet recording apparatus according to claim 23 ,
An orientation control layer comprising a perovskite oxide preferentially oriented in a cubic or tetragonal (100) plane or (001) plane between a first electrode layer and a piezoelectric layer of a piezoelectric element in an inkjet head An ink jet recording apparatus comprising: A piezoelectric element in which a first electrode layer, a piezoelectric layer, and a second electrode layer are sequentially laminated; a vibration layer provided on a surface of the piezoelectric element on the first electrode layer side; An inkjet head having a pressure chamber member bonded to a surface opposite to the piezoelectric element and having a pressure chamber for containing ink and configured to be movable relative to a recording medium, the inkjet head recording When moving relative to the medium, the vibration layer is displaced in the layer thickness direction by the piezoelectric effect of the piezoelectric layer of the piezoelectric element in the ink jet head, and the ink in the pressure chamber communicates with the pressure chamber. An ink jet recording apparatus configured to perform recording by discharging the nozzle holes to the recording medium,
The first electrode layer of the piezoelectric element in the inkjet head is made of an alloy of at least one metal selected from the group consisting of cobalt, nickel, iron, manganese and copper and a noble metal,
The content of at least one metal selected from the group of cobalt, nickel, iron, manganese and copper in the first electrode layer is more than 0 and 26 mol% or less;
2. The ink jet recording apparatus according to claim 1, wherein the piezoelectric layer is made of a perovskite oxide preferentially oriented in a rhombohedral or tetragonal (001) plane. The ink jet recording apparatus according to claim 25 ,
An orientation control layer comprising a perovskite oxide preferentially oriented in a cubic or tetragonal (100) plane or (001) plane between a first electrode layer and a piezoelectric layer of a piezoelectric element in an inkjet head An ink jet recording apparatus comprising:

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