JPH111768A - Target for ferroelectric thin film, its production and ferroelectric thin film - Google Patents
Target for ferroelectric thin film, its production and ferroelectric thin filmInfo
- Publication number
- JPH111768A JPH111768A JP9153193A JP15319397A JPH111768A JP H111768 A JPH111768 A JP H111768A JP 9153193 A JP9153193 A JP 9153193A JP 15319397 A JP15319397 A JP 15319397A JP H111768 A JPH111768 A JP H111768A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- target
- ferroelectric thin
- lead zirconate
- zirconate titanate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明はチタン酸ジルコン酸
鉛薄膜等の強誘電体薄膜をスパッタリング法などで作る
のに用いる強誘電体薄膜用ターゲットおよびその製造方
法、およびそのターゲットを用いて作った強誘電体薄膜
に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ferroelectric thin film target used for forming a ferroelectric thin film such as a lead zirconate titanate thin film by a sputtering method or the like, a method for manufacturing the same, and a target manufactured using the target. The present invention relates to a ferroelectric thin film.
【０００２】[0002]
【従来の技術】チタン酸ジルコン酸鉛薄膜等の強誘電体
薄膜に電極を取り付けた強誘電体薄膜素子は、例えば不
揮発性メモリ、ダイナミックランダムアクセスメモリの
キャパシタ、圧電素子、光素子等に用いられる。2. Description of the Related Art A ferroelectric thin film element in which an electrode is attached to a ferroelectric thin film such as a lead zirconate titanate thin film is used, for example, for a nonvolatile memory, a capacitor of a dynamic random access memory, a piezoelectric element, an optical element and the like. .
【０００３】このような強誘電体薄膜の製造には、真空
蒸着法、スパッタリング法、レーザーアブレーション法
等の物理的方法、および、有機金属化合物を出発原料と
し、これらを熱分解酸化して酸化物強誘電体を得るゾル
ゲル法、ＭＯＤ(Metal Organic Deposition)法、ＣＶＤ
(Chemical Vapor Deposition) 法等の化学的方法が用い
られている。In order to manufacture such a ferroelectric thin film, a physical method such as a vacuum evaporation method, a sputtering method, or a laser ablation method, or an organic metal compound is used as a starting material, and these are thermally decomposed and oxidized to form an oxide. Sol-gel method to obtain ferroelectric, MOD (Metal Organic Deposition) method, CVD
Chemical methods such as (Chemical Vapor Deposition) method are used.
【０００４】これらのなかでスパッタリング法は、ター
ゲット組成と出来上がった薄膜の組成を同じにすること
ができるほかに、厚さの厚い薄膜を容易に作ることがで
きるので、最も実用的可能性のあるものである。チタン
酸ジルコン酸鉛スパッタ薄膜の作成においては、温度あ
るいは再スパッタによってＰｂの再蒸発が起こることが
広く認められており、形成される膜のＰｂ量はスパッタ
雰囲気、ガス圧、基板温度、スパッタ電力などの条件に
よって大きく変化する。[0004] Among them, the sputtering method has the most practical possibility because the target composition and the composition of the completed thin film can be made the same, and a thin film having a large thickness can be easily formed. Things. In the preparation of sputtered thin films of lead zirconate titanate, it is widely accepted that Pb is re-evaporated by temperature or re-sputtering, and the amount of Pb in the formed film depends on the sputter atmosphere, gas pressure, substrate temperature, sputter power. It varies greatly depending on conditions such as
【０００５】チタン酸ジルコン酸鉛薄膜の組成は、その
特性、例えば不揮発性メモリに応用する際には残留分
極、抗電場などが重要な特性となるが、これらの特性を
最適化するにはチタン酸ジルコン酸鉛薄膜は化学量論組
成であることが望ましい。このため、Ｐｂをいかに制御
して化学量論組成を得るかについて多くの努力がなされ
ている。[0005] The composition of a lead zirconate titanate thin film has important properties such as remanent polarization and coercive electric field when applied to a non-volatile memory. It is desirable that the lead zirconate thin film has a stoichiometric composition. Therefore, many efforts have been made on how to control Pb to obtain a stoichiometric composition.
【０００６】例えば、Ｐｂ，Ｚｒ，Ｔｉの金属を配置し
たターゲットや、複数のターゲットを用いる多元スパッ
タ法が試みられている。これら多元スパッタ法では設備
が大きく煩雑になり、各ターゲット毎に条件を精密に制
御する必要があるので、その化学量論組成を精密に制御
することは困難であった。For example, a target on which metals of Pb, Zr, and Ti are arranged, and a multi-source sputtering method using a plurality of targets have been tried. In these multi-source sputtering methods, the equipment becomes large and complicated, and the conditions must be precisely controlled for each target. Therefore, it has been difficult to precisely control the stoichiometric composition.
【０００７】また、チタン酸ジルコン酸鉛の化合物粉末
（必要によりＬａを添加したもの、Ｚｒを除いたものを
含んで）の表面をＰｂＯ粒子で被覆したものを用いそれ
をホットプレスしてスパッタリング用ターゲットとした
ものも提案されている（例えば、特開平６−５６５２８
号公報）。このようなターゲットの場合には、ＰｂＯ粉
末がチタン酸ジルコン酸鉛の表面に付着しているために
ＰｂＯが先にスパッタリングされるという可能性があ
る。[0007] A compound powder of lead zirconate titanate (including a powder to which La has been added and a powder to which Zr has been removed, if necessary) coated with PbO particles is used and hot-pressed for sputtering. Targets have also been proposed (for example, see JP-A-6-56528).
No.). In the case of such a target, there is a possibility that PbO is sputtered first because the PbO powder adheres to the surface of lead zirconate titanate.
【０００８】[0008]
【発明が解決しようとする課題】そこで本発明では、ス
パッタリングによって化学量論的組成をした均一な強誘
電体薄膜を得ることのできる焼結体ターゲットおよびそ
の製造方法を提供することを目的としている。Accordingly, an object of the present invention is to provide a sintered target capable of obtaining a uniform ferroelectric thin film having a stoichiometric composition by sputtering, and a method of manufacturing the same. .
【０００９】また、スパッタリングによって得られた薄
膜の熱処理に対して安定な組成となっており、大きな残
留分極を得ることのできる強誘電体薄膜を得ることので
きる焼結体ターゲットを提供することを目的としてい
る。It is another object of the present invention to provide a sintered target capable of obtaining a ferroelectric thin film having a composition stable to heat treatment of a thin film obtained by sputtering and obtaining a large remanent polarization. The purpose is.
【００１０】また、本発明では、残留分極の劣化の小さ
い強誘電体薄膜を得ることのできる焼結体ターゲットを
提供することも目的としている。また、本発明では上記
ターゲットで作成することのできる強誘電体薄膜を提供
することも目的としている。It is another object of the present invention to provide a sintered target capable of obtaining a ferroelectric thin film with little deterioration of remanent polarization. Another object of the present invention is to provide a ferroelectric thin film that can be formed using the above target.
【００１１】[0011]
【課題を解決するための手段】本発明の強誘電体薄膜用
ターゲットは、チタン酸ジルコン酸鉛焼結体中のＰｂ，
Ｚｒ，ＴｉがＰｂ／（Ｚｒ＋Ｔｉ）のモル比で１．０２
〜１．３０であることを特徴とするものである。ここ
で、チタン酸ジルコン酸鉛焼結体中にＰｂ（Ｚｒ，Ｔ
ｉ）Ｏ3 とＰｂ2 （Ｚｒ，Ｔｉ）Ｏ3 が共存しているこ
とが望ましい。According to the present invention, there is provided a ferroelectric thin film target comprising Pb,
Zr and Ti are 1.02 in a molar ratio of Pb / (Zr + Ti).
３０1.30. Here, Pb (Zr, T) is contained in the lead zirconate titanate sintered body.
i) It is desirable that O 3 and Pb 2 (Zr, Ti) O 3 coexist.
【００１２】また、本発明の強誘電体薄膜用ターゲット
は、チタン酸ジルコン酸鉛焼結体の中のＰｂの一部を５
モル％以下のＢａあるいはＳｒ、好ましくは０．５〜５
モル％のＢａあるいはＳｒで置換したことを特徴とする
ものである。Further, the ferroelectric thin film target of the present invention is characterized in that a part of Pb in the lead zirconate titanate sintered body is reduced to 5%.
Less than mol% of Ba or Sr, preferably 0.5 to 5
It is characterized by being substituted by mol% of Ba or Sr.
【００１３】また、本発明の強誘電体薄膜用ターゲット
は、チタン酸ジルコン酸鉛焼結体のＺｒあるいは／およ
びＴｉの一部をＭｎ，Ｆｅ，Ｓｂ，Ｎｂの少なくとも一
種の元素で置換したことを特徴とするものである。ここ
で、Ｍｎ，Ｆｅ，Ｓｂ，Ｎｂなどの置換量はＺｒあるい
は／およびＴｉの含有量の１／１０以下であることが好
ましい。Further, in the ferroelectric thin film target of the present invention, a part of Zr and / or Ti of the lead zirconate titanate is replaced with at least one element of Mn, Fe, Sb and Nb. It is characterized by the following. Here, the substitution amount of Mn, Fe, Sb, Nb and the like is preferably 1/10 or less of the content of Zr and / or Ti.
【００１４】また、本発明の強誘電体薄膜用ターゲット
は、密度が7.50g/cm3 以上であることも一つの特徴であ
る。本発明の強誘電体薄膜用ターゲットの製造方法にお
いては、チタン酸ジルコン酸鉛の成形体を２気圧以上の
酸素雰囲気中で焼結することを特徴とするものである。Another feature of the ferroelectric thin film target of the present invention is that the density is 7.50 g / cm 3 or more. In the method for manufacturing a target for a ferroelectric thin film according to the present invention, a compact of lead zirconate titanate is sintered in an oxygen atmosphere at 2 atm or more.
【００１５】また、上記の強誘電体薄膜用ターゲットを
用いて作成した強誘電体薄膜も本発明である。本発明の
強誘電体薄膜は、チタン酸ジルコン酸鉛の中のＰｂの一
部を５モル％以下のＢａあるいはＳｒ，好ましくは０．
５〜５モル％のＢａあるいはＳｒで置換した組成をして
いることを特徴とする。The present invention also relates to a ferroelectric thin film formed using the above ferroelectric thin film target. In the ferroelectric thin film of the present invention, a part of Pb in the lead zirconate titanate is preferably 5 mol% or less of Ba or Sr, preferably 0.1 mol% or less.
It is characterized by having a composition substituted with 5 to 5 mol% of Ba or Sr.
【００１６】また、本発明の強誘電体薄膜は、チタン酸
ジルコン酸鉛のＺｒあるいは／およびＴｉの一部をＭ
ｎ，Ｆｅ，Ｓｂ，Ｎｂの少なくとも一種の元素で置換し
たことを特徴とするものである。ここで、Ｍｎ，Ｆｅ，
Ｓｂ，Ｎｂなどの置換量はＺｒあるいは／およびＴｉの
含有量の１／１０以下であることが好ましい。In the ferroelectric thin film of the present invention, a part of Zr and / or Ti of the lead zirconate titanate is changed to M
It is characterized by being substituted by at least one element of n, Fe, Sb and Nb. Here, Mn, Fe,
The substitution amount of Sb, Nb and the like is preferably 1/10 or less of the content of Zr and / or Ti.
【００１７】本発明で「チタン酸ジルコン酸鉛」という
語は、代表組成がＰｂ（Ｚｒ，Ｔｉ）Ｏ3 で示される組
成物（ＰＺＴと略称することがある）と、その鉛の一部
をＬａなどの希土類元素で置換した代表組成が（Ｐｂ，
Ｌａ）（Ｚｒ，Ｔｉ）Ｏ3 で示される組成物（ＰＬＺＴ
と略称することがある）と、その鉛の一部をＬａなどの
希土類元素で置換しＺｒを含有しない代表組成が（Ｐ
ｂ，Ｌａ）ＴｉＯ3 で示される組成物（ＰＬＴと略称す
ることがある）と、Ｚｒを含有しない代表組成がＰｂＴ
ｉＯ3 で示される組成物（ＰＴと略称することがある）
とを総称するものとする。In the present invention, the term "lead zirconate titanate" refers to a composition whose representative composition is represented by Pb (Zr, Ti) O 3 (sometimes abbreviated as PZT) and a part of the lead. A typical composition replaced by a rare earth element such as La is (Pb,
La) A composition represented by (Zr, Ti) O 3 (PLZT
(Sometimes abbreviated as “Pb”), and a typical composition that does not contain Zr and a part of the lead is replaced by a rare earth element such as La is (P
b, La) a composition represented by TiO 3 (sometimes abbreviated as PLT) and a representative composition not containing Zr being PbT
Composition represented by iO 3 (may be abbreviated as PT)
Are generically referred to.
【００１８】[0018]
【発明の実施の形態】本発明の強誘電体薄膜用ターゲッ
トで、チタン酸ジルコン酸鉛焼結体中のＰｂ、Ｚｒ、Ｔ
ｉがＰｂ／（Ｚｒ＋Ｔｉ）のモル比で１．０２〜１．３
０としているのは、焼結時に蒸発しやすく成分変動の生
じやすいＰｂを化学量論的組成よりも少し過剰にするこ
とによって、ターゲットおよびそれをスパッタリングし
て得られた薄膜、またその後で熱処理を施した薄膜の組
成を化学量論的組成に近いものに保つのに必要である。
さらにターゲット内のＰｂ量のばらつきを極力小さくす
るためにはターゲットの焼結密度をできるだけ高く、好
ましくは7.50g/cm3 以上にすることが有効である。これ
は密度の低い、すなわち空孔の多い焼結体では空孔部近
傍ではＰｂの蒸発が多く、焼結体中のＰｂが減少するの
に対して、空孔に隣接していない部分ではＰｂの蒸発が
少なく、焼結体中のＰｂが減少しないために、ターゲッ
ト全体としてはＰｂ濃度にばらつきを生じやすくなるた
めである。Ｐｂ／（Ｚｒ＋Ｔｉ）のモル比が１．０２未
満では焼結体の中のＰｂが不足してその密度が7.50g/cm
3 未満となる。Ｐｂ／（Ｚｒ＋Ｔｉ）のモル比が増える
に従い密度は上昇する。このモル比が１．３０を超える
と、更に密度は上昇するがＰｂＯを主成分とする液相量
が多くなりすぎて、焼結体表面にＰｂＯが滲み出し、均
一な組成の焼結体を得ることができない。BEST MODE FOR CARRYING OUT THE INVENTION The ferroelectric thin film target of the present invention is a target for Pb, Zr, T in lead zirconate titanate sintered body.
i is 1.02 to 1.3 in a molar ratio of Pb / (Zr + Ti).
The reason why 0 is set is that the target and the thin film obtained by sputtering the target and the thin film obtained by sputtering the target, and Pb, which are easily evaporated during sintering and have a small excess of Pb, which tends to cause component fluctuation, are used. It is necessary to keep the composition of the applied thin film close to the stoichiometric composition.
Further, in order to minimize variations in the amount of Pb in the target, it is effective to increase the sintered density of the target as high as possible, preferably to 7.50 g / cm 3 or more. This is because, in a sintered body having a low density, that is, in a sintered body having many pores, Pb is largely evaporated in the vicinity of the pores and Pb in the sintered body is reduced, whereas Pb in a part not adjacent to the pores is reduced. This is because evaporation of Pb in the sintered body does not decrease and the Pb concentration in the target as a whole tends to vary. If the molar ratio of Pb / (Zr + Ti) is less than 1.02, Pb in the sintered body is insufficient and the density is 7.50 g / cm.
Less than 3 . The density increases as the molar ratio of Pb / (Zr + Ti) increases. When this molar ratio exceeds 1.30, the density further increases, but the amount of the liquid phase containing PbO as a main component becomes too large, and PbO seeps out to the surface of the sintered body, and a sintered body having a uniform composition is obtained. I can't get it.
【００１９】この際、過剰のＰｂＯはガラス相として存
在すると焼結時に蒸発しやすいために、予めＰｂ2 （Ｚ
ｒ，Ｔｉ）Ｏ3 となるように仮焼しておき、このＰｂ2
（Ｚｒ，Ｔｉ）Ｏ3 をＰｂ（Ｚｒ，Ｔｉ）Ｏ3 に混合し
てこれらの２相が共存するようにしておくとよい。At this time, if excess PbO is present as a glass phase, it is likely to evaporate during sintering, so that Pb 2 (Z
(r, Ti) O 3, and calcined to obtain Pb 2
(Zr, Ti) O 3 is preferably mixed with Pb (Zr, Ti) O 3 so that these two phases coexist.
【００２０】本発明の強誘電体薄膜用ターゲットを製造
する場合、主成分の原料であるＰｂＯ，ＺｒＯ2 ，Ｔｉ
Ｏ2 および必要によりＬａ2 Ｏ3 を所望の組成となるよ
うに秤量して、水でスラリーとしてボールミルで混合、
乾燥する。これを約８００℃で、約２時間仮焼きし、ボ
ールミルで粉砕し、その後、所定形状に成形する。この
成形体を高純度マグネシアセッターなどの上に配置し
て、酸素加圧炉で所定条件で焼結をする。この焼結体を
研磨加工した後、ろう材を用いてバッキングプレートに
ボンディングを行ってターゲットとする。When manufacturing the ferroelectric thin film target of the present invention, PbO, ZrO 2 , Ti
O 2 and, if necessary, La 2 O 3 are weighed so as to have a desired composition, mixed as a slurry with water in a ball mill,
dry. This is calcined at about 800 ° C. for about 2 hours, crushed by a ball mill, and then formed into a predetermined shape. This compact is placed on a high-purity magnesia setter or the like, and sintered under a predetermined condition in an oxygen pressurizing furnace. After polishing this sintered body, it is bonded to a backing plate using a brazing material to obtain a target.
【００２１】強誘電体薄膜を作るには、この焼結体ター
ゲットを用いて、スパッタガスとしてアルゴンと酸素の
混合ガスを用いガス圧を１５Ｐａとして、高周波電力４
００Ｗの高周波マグネトロンスパッタリング法によりチ
タン酸ジルコン酸鉛薄膜を作成する。基板には、石英ガ
ラス基板や、シリコン基板上に厚さ約１０００Åの熱酸
化膜を形成した後、その上にＤＣスパッタ法により厚さ
約１０００Åの白金膜を形成したものを用いた。In order to form a ferroelectric thin film, a high-frequency power of 4 Pa is used by using this sintered target, using a mixed gas of argon and oxygen as a sputtering gas, and setting the gas pressure to 15 Pa.
A lead zirconate titanate thin film is formed by 00 W high frequency magnetron sputtering. As the substrate, a quartz glass substrate or a silicon substrate was used, in which a thermal oxide film having a thickness of about 1000 形成 was formed, and a platinum film having a thickness of about 1000 に よ り was formed thereon by DC sputtering.
【００２２】その後この強誘電体薄膜を、酸素中５７０
〜６５０℃で熱処理をすることで結晶化させてペロブス
カイト結晶構造とする。上記で、過剰分のＰｂをＰｂ2
（Ｚｒ，Ｔｉ）Ｏ3 として混合することが望ましい。Thereafter, this ferroelectric thin film is formed by
It is crystallized by heat treatment at ６650 ° C. to obtain a perovskite crystal structure. In the above, excess Pb is converted to Pb 2
It is desirable to mix them as (Zr, Ti) O 3 .
【００２３】また、酸素加圧炉で焼結する際、この酸素
分圧を２気圧以上としてＰｂＯの蒸発を防ぐ。焼結温度
をＰｂＯの蒸気圧が高くなる１１００℃以下に保つこと
も有効なことである。When sintering in an oxygen pressurizing furnace, the oxygen partial pressure is set to 2 atm or more to prevent evaporation of PbO. It is also effective to keep the sintering temperature at 1100 ° C. or lower at which the vapor pressure of PbO increases.
【００２４】強誘電体薄膜用ターゲットのチタン酸ジル
コン酸鉛焼結体のなかのＰｂの一部を５モル％以下のＢ
ａあるいはＳｒ、好ましくは０．５〜５モル％のＢａあ
るいはＳｒで置換したことによって、このターゲットを
用いてスパッタリングして作った強誘電体薄膜はそのチ
タン酸ジルコン酸鉛のＰｂの一部が５モル％以下のＢａ
あるいはＳｒ，好ましくは０．５〜５モル％のＢａある
いはＳｒで置換した組成となる。このようにＰｂの一部
をＢａあるいはＳｒで置換することによって、強誘電体
薄膜を熱処理する際の熱処理温度を上げてもＰｂの蒸発
を抑制することができる。このことによって残留分極Ｐ
ｒを大きくすることができる。置換量が１．０モル％を
超えるとＰｂの蒸発を大幅に抑制することができる。Ｂ
ａとＳｒは、ほぼ同じ働きがある。置換量が５モル％を
超えると残留分極が低下するので、５モル％以下の置換
が望ましい。A part of Pb in the lead zirconate titanate sintered body as a target for a ferroelectric thin film is changed to a B content of 5 mol% or less.
By substituting with a or Sr, preferably 0.5 to 5 mol% of Ba or Sr, the ferroelectric thin film formed by sputtering using this target has a part of Pb of the lead zirconate titanate. Ba of 5 mol% or less
Alternatively, the composition is replaced with Sr, preferably 0.5 to 5 mol% of Ba or Sr. By substituting a part of Pb with Ba or Sr in this way, evaporation of Pb can be suppressed even when the heat treatment temperature when the ferroelectric thin film is heat-treated is increased. This allows the remanent polarization P
r can be increased. If the substitution amount exceeds 1.0 mol%, the evaporation of Pb can be greatly suppressed. B
a and Sr have almost the same function. When the substitution amount exceeds 5 mol%, the remanent polarization decreases. Therefore, substitution of 5 mol% or less is desirable.
【００２５】強誘電体薄膜用ターゲットのチタン酸ジル
コン酸鉛焼結体の中のＺｒ，Ｔｉの一部をＭｎ，Ｆｅ，
Ｓｂ，Ｎｂの少なくとも一種の元素で置換することによ
って、このターゲットを用いてスパッタして作った強誘
電体薄膜はそのチタン酸ジルコン酸鉛のＺｒ，Ｔｉの一
部をＭｎ，Ｆｅ，Ｓｂ，Ｎｂの少なくとも一種の元素で
置換した組成となる。このように、Ｚｒ，Ｔｉの一部を
Ｍｎ，Ｆｅ，Ｓｂ，Ｎｂの少なくとも一種の元素で置換
した組成の強誘電体薄膜は分域反転の繰り返し試験に対
して残留分極の低下が少なく、劣化の小さいものとな
る。この置換量はＺｒ，Ｔｉの含有量の１／１０以下が
望ましい。A part of Zr and Ti in the lead zirconate titanate sintered body as the target for the ferroelectric thin film is replaced with Mn, Fe,
By substituting at least one element of Sb and Nb, the ferroelectric thin film formed by sputtering using this target can partially convert Zr and Ti of the lead zirconate titanate to Mn, Fe, Sb and Nb. In which at least one element is substituted. As described above, a ferroelectric thin film having a composition in which a part of Zr and Ti is replaced with at least one element of Mn, Fe, Sb, and Nb has a small decrease in remanent polarization in a repeated domain inversion test, and shows a deterioration. Will be smaller. This substitution amount is desirably 1/10 or less of the Zr and Ti contents.
【００２６】[0026]
（実施例１）１５０ｍｍ径で厚さ６ｍｍの大きさをし、
表１に示したＰｂ／（Ｚｒ＋Ｔｉ）のモル比（ｘ）をし
たチタン酸ジルコン酸鉛ターゲット（組成式：Ｐｂx Ｚ
ｒ0. 5 Ｔｉ0.5 Ｏ3 ）を１１００℃で５時間焼結して作
成した。各ターゲットの焼結時の酸素圧力を同表に示し
た。このターゲットから、１０ｍｍ×１０ｍｍ×６ｍｍ
厚の試験片をターゲットの中央部から１個、外周部近傍
から4 個の計５個を切り出し、密度およびＰｂ量を測定
した。密度は水中置換法により、Ｐｂ量は誘導結合プラ
ズマ発光分光法によりそれぞれ測定した。表１に結果を
示す。密度はそれぞれ５点の平均を、また、Ｐｂ量は５
点の最大値と最小値を示す。なお、表１中のＮｏ．６は
Ｐｂ1.0 Ｚｒ0.5 Ｔｉ0.5 Ｏ3 とＰｂ2.0 Ｚｒ0.5 Ｔｉ
0.5 Ｏ3に相当するように秤量した原料粉を予め８００
℃で仮焼きし、それぞれの仮焼き粉を７０モル％と３０
モル％混合したものを焼結したものである。(Example 1) A 150 mm diameter, 6 mm thick,
A lead zirconate titanate target (composition formula: Pb x Z) having a molar ratio (x) of Pb / (Zr + Ti) shown in Table 1
It created a r 0. 5 Ti 0.5 O 3) and sintered for 5 hours at 1100 ° C.. The oxygen pressure during sintering of each target is shown in the table. From this target, 10mm x 10mm x 6mm
One thick test piece was cut out from the center of the target, and four pieces were cut out from the vicinity of the outer periphery, for a total of five pieces, and the density and Pb amount were measured. The density was measured by a water displacement method, and the Pb content was measured by inductively coupled plasma emission spectroscopy. Table 1 shows the results. The density is the average of 5 points, and the Pb content is 5
Shows the maximum and minimum points. In addition, in Table 1, No. 6 is Pb 1.0 Zr 0.5 Ti 0.5 O 3 and Pb 2.0 Zr 0.5 Ti
Raw material powder weighed to correspond to 0.5 O 3
Calcination at 70 ° C.
It is obtained by sintering a mixture of mol%.
【００２７】[0027]
【表１】 [Table 1]
【００２８】Ｎｏ．１〜３と比較例１はいずれもモル比
ｘ＝Ｐｂ／（Ｚｒ＋Ｔｉ）：１．０５とした組成のもの
を焼結時の酸素圧力を変えて焼結したもので、酸素圧力
が２気圧以上で焼結密度が7.50g/cm3 以上となっており
緻密な焼結体が得られており、組成ばらつき（Ｐｂ量ば
らつき）の小さなターゲットが得られていることがわか
る。No. Each of Comparative Examples 1 to 3 and Comparative Example 1 was obtained by sintering a composition having a molar ratio x = Pb / (Zr + Ti): 1.05 while changing the oxygen pressure during sintering. It can be seen that the sintered density was 7.50 g / cm 3 or more, a dense sintered body was obtained, and a target with small composition variation (Pb amount variation) was obtained.
【００２９】比較例２とＮｏ．２，４〜６および比較例
３はいずれも焼結時の酸素圧力を５気圧としたもので、
モル比ｘ＝Ｐｂ／（Ｚｒ＋Ｔｉ）を１．０１から１．４
０まで変えたものである。比較例２からわかるようにモ
ル比ｘ＝Ｐｂ／（Ｚｒ＋Ｔｉ）が１．０２未満では焼結
密度が低下し、組成ばらつきも大きくなる。また、比較
例３のようにＰｂ／（Ｚｒ＋Ｔｉ）モル比が１．３０を
超えると焼結密度は上昇するが、ガラス化したＰｂＯが
しみ出して、組成ばらつきが大きくなる。そこで、モル
比は１．０２〜１．３０が適当であることがわかる。Comparative Example 2 and No. 2, 4 to 6 and Comparative Example 3 each had an oxygen pressure of 5 atm during sintering.
The molar ratio x = Pb / (Zr + Ti) is changed from 1.01 to 1.4.
It is changed to 0. As can be seen from Comparative Example 2, when the molar ratio x = Pb / (Zr + Ti) is less than 1.02, the sintering density decreases and the composition variation increases. Further, when the molar ratio of Pb / (Zr + Ti) exceeds 1.30 as in Comparative Example 3, the sintered density increases, but vitrified PbO exudes and the composition variation increases. Thus, it is found that the molar ratio is suitably from 1.02 to 1.30.
【００３０】また、Ｎｏ．５と６の比較から、Ｐｂ1.0
Ｚｒ0.5 Ｔｉ0.5 Ｏ3 とＰｂ2.0 Ｚｒ0.5 Ｔｉ0.5 Ｏ3
の混合粉を用いたＮｏ．６は組成ばらつきが一層小さく
なっていることがわかる。Further, No. From the comparison between 5 and 6, Pb 1.0
Zr 0.5 Ti 0.5 O 3 and Pb 2.0 Zr 0.5 Ti 0.5 O 3
No. using the mixed powder of 6, it can be seen that the composition variation is further reduced.
【００３１】（実施例２）ＰＺＴ（組成式Ｐｂ1.05Ｚｒ
0.5 Ｔｉ0.5 Ｏ3 ）ターゲット、ＰＢＺＴ（組成式Ｐｂ
1.05-xＢａx Ｚｒ0.5 Ｔｉ0.5 Ｏ3 ）ターゲット、ＰＳ
ＺＴ（組成式Ｐｂ 1.05-xＳｒx Ｚｒ0.5 Ｔｉ0.5 Ｏ3 ）
ターゲットを用いて基板温度１８０℃でスパッタリング
した約２０００Åの薄膜を１気圧１００％酸素中で熱処
理をしてペロブスカイト構造とした強誘電体薄膜上に真
空蒸着法で２０００Åの白金薄膜を形成して上部電極と
した試料について残留分極（Ｐｒ）を測定した。また、
熱処理前後のＰｂ量（重量％）は誘導結合プラズマ発光
分光分析法により分析した。(Example 2) PZT (composition formula Pb1.05Zr
0.5Ti0.5OThree) Target, PBZT (composition formula Pb)
1.05-xBaxZr0.5Ti0.5OThree) Target, PS
ZT (composition formula Pb 1.05-xSrxZr0.5Ti0.5OThree)
Sputtering at a substrate temperature of 180 ° C using a target
The thin film of about 2000mm was heat treated in 100% oxygen at 1 atm.
Process on a ferroelectric thin film with a perovskite structure.
2000mm platinum thin film is formed by vacuum evaporation method
The remanent polarization (Pr) of the sample thus obtained was measured. Also,
Pb content (% by weight) before and after heat treatment is inductively coupled plasma emission
Analyzed by spectroscopy.
【００３２】[0032]
【表２】 [Table 2]
【００３３】Ｎｏ．１，２のようにＢａまたはＳｒの置
換されていない場合では熱処理温度を高くできないので
結晶性が低く角型性の低い、すなわちＰｒの低い薄膜と
なってしまうが、Ｐｂの一部をＢａまたはＳｒで置換す
ることによりＰｂの蒸発を抑制し、熱処理温度を高める
ことができるので、結晶性の高い、すなわち特性的には
角型性の良い、強誘電体薄膜を得ることができた。表２
の比較例に示すように置換量が５モル％を超えるとＰｒ
が低下して置換の効果がでない。No. In the case where Ba or Sr is not substituted as in Examples 1 and 2, the heat treatment temperature cannot be increased, so that the crystallinity is low and the squareness is low, that is, a thin film with low Pr is obtained. By substituting with Sr, the evaporation of Pb can be suppressed, and the heat treatment temperature can be increased, so that a ferroelectric thin film having high crystallinity, that is, having good squareness in characteristics can be obtained. Table 2
When the substitution amount exceeds 5 mol%, Pr
And the effect of substitution is not obtained.
【００３４】（実施例３）ＰＺＴターゲットのＺｒとＴ
ｉの一部を他の元素Ｍ（ＭはＭｎ，Ｆｅ，ＳｂまたはＮ
ｂのいずれか一種）で置換したターゲット（組成式：Ｐ
ｂ1.05Ｚｒ0.5-x/ 2 Ｔｉ0.5-x/2 Ｍx Ｏ3 でｘ＝０．０
３）を用いて実施例２と同様の方法で強誘電体薄膜を作
成した。得られた薄膜の疲労特性は、±３Ｖで分域反転
の繰り返し試験を１０9 回行って試験前後の残留分極を
測定することで評価した。(Embodiment 3) Zr and T of PZT target
i is converted to another element M (M is Mn, Fe, Sb or N
(composition formula: P)
b 1.05 Zr 0.5-x / 2 2 Ti 0.5-x / 2 M x O 3 and x = 0.0
Using 3), a ferroelectric thin film was prepared in the same manner as in Example 2. The fatigue characteristics of the obtained thin film were evaluated by repeating a domain reversal test at ± 3 V 10 9 times and measuring remanent polarization before and after the test.
【００３５】表３にその試験結果を示す。薄膜の劣化が
大きいものほど試験後の残留分極の低下が著しく、２Ｐ
r （試験後）／２Ｐr （試験前）比が小さくなる。この
表から明らかなように、ＺｒとＴｉの一部をＭｎ，Ｆ
ｅ，ＳｂまたはＮｂのいずれか一種の元素で置換するこ
とにより、分域反転による薄膜の劣化が少なくなってい
ることがわかる。Table 3 shows the test results. As the deterioration of the thin film becomes larger, the remanent polarization after the test decreases more remarkably.
r (after test) / 2Pr (before test) ratio decreases. As is clear from this table, a part of Zr and Ti is replaced with Mn, F
It can be seen that by substituting any one element of e, Sb or Nb, deterioration of the thin film due to domain inversion is reduced.
【００３６】[0036]
【表３】 [Table 3]
【００３７】[0037]
【発明の効果】本発明によって、スパッタリングをする
ことによって化学量論的組成をした強誘電体薄膜を得る
ことのできる強誘電体薄膜用ターゲットおよびその製造
方法を得ることができた。また、スパッタリングをして
得られた薄膜を熱処理してもそのＰｂの蒸発を小さく抑
えることができる組成をしたターゲットおよびそれから
得た強誘電体薄膜を得ることができ、大きな残留分極を
持ったものが得られた。According to the present invention, it is possible to obtain a ferroelectric thin film target capable of obtaining a ferroelectric thin film having a stoichiometric composition by sputtering, and a method of manufacturing the same. In addition, a target having a composition capable of suppressing evaporation of Pb even when a thin film obtained by sputtering is heat-treated and a ferroelectric thin film obtained therefrom can be obtained, and have a large remanent polarization. was gotten.
【００３８】また、残留分極の劣化の小さな強誘電体薄
膜およびそれを作成することのできるターゲットを得る
ことができた。Further, it was possible to obtain a ferroelectric thin film with small deterioration of remanent polarization and a target from which the ferroelectric thin film could be formed.
Claims (12)
Ｚｒ，ＴｉがＰｂ／（Ｚｒ＋Ｔｉ）のモル比で１．０２
〜１．３０であることを特徴とする強誘電体薄膜用ター
ゲット。1. The method according to claim 1, wherein Pb,
Zr and Ti are 1.02 in a molar ratio of Pb / (Zr + Ti).
1. A target for a ferroelectric thin film, wherein
（Ｚｒ，Ｔｉ）Ｏ3 とＰｂ2 （Ｚｒ，Ｔｉ）Ｏ3 が共存
していることを特徴とする請求項１記載の強誘電体薄膜
用ターゲット。2. Pb in a lead zirconate titanate sintered body.
(Zr, Ti) O 3 and Pb 2 (Zr, Ti) a ferroelectric thin film target of claim 1, wherein the O 3 is equal to or coexisting.
部を５モル％以下のＢａあるいはＳｒで置換したことを
特徴とする請求項１あるいは２記載の強誘電体薄膜用タ
ーゲット。3. The ferroelectric thin film target according to claim 1, wherein a part of Pb of the lead zirconate titanate sintered body is substituted with 5 mol% or less of Ba or Sr.
部を０．５〜５モル％のＢａあるいはＳｒで置換したこ
とを特徴とする請求項３記載の強誘電体薄膜用ターゲッ
ト。4. The ferroelectric thin film target according to claim 3, wherein a part of Pb of the lead zirconate titanate sintered body is substituted with 0.5 to 5 mol% of Ba or Sr.
いは／およびＴｉの一部をＭｎ，Ｆｅ，Ｓｂ，Ｎｂの少
なくとも一種の元素で置換したことを特徴とする請求項
１〜４いずれか記載の強誘電体薄膜用ターゲット。5. The lead zirconate titanate sintered body according to claim 1, wherein a part of Zr and / or Ti is replaced by at least one element of Mn, Fe, Sb and Nb. The target for a ferroelectric thin film according to the above.
いは／およびＴｉの含有量の１／１０以下をＭｎ，Ｆ
ｅ，Ｓｂ，Ｎｂの少なくとも一種の元素で置換したこと
を特徴とする請求項５記載の強誘電体薄膜用ターゲッ
ト。6. The method according to claim 1, wherein the content of Zr and / or Ti in the sintered body of lead zirconate titanate is Mn, F or less.
6. The ferroelectric thin film target according to claim 5, wherein said target is substituted with at least one element of e, Sb, and Nb.
50g/cm3 以上であることを特徴とする請求項１〜６のい
ずれか記載の強誘電体薄膜用ターゲット。7. The lead zirconate titanate sintered body having a density of 7.
7. The ferroelectric thin film target according to claim 1, wherein the target is 50 g / cm 3 or more.
ルコン酸鉛焼結体の製造において、チタン酸ジルコン酸
鉛の成形体を２気圧以上の酸素雰囲気中で焼結すること
を特徴とする強誘電体薄膜用ターゲットの製造方法。8. The method of producing a lead zirconate titanate sintered body according to claim 1, wherein the molded body of lead zirconate titanate is sintered in an oxygen atmosphere of 2 atm or more. For producing a ferroelectric thin film target.
モル％以下のＢａあるいはＳｒで置換したことを特徴と
する強誘電体薄膜。9. Pb of lead zirconate titanate is partially substituted with 5
A ferroelectric thin film characterized by being substituted by not more than mol% of Ba or Sr.
０．５〜５モル％のＢａあるいはＳｒで置換したことを
特徴とする請求項９記載の強誘電体薄膜。10. The ferroelectric thin film according to claim 9, wherein a part of Pb of the lead zirconate titanate is substituted with 0.5 to 5 mol% of Ba or Sr.
／およびＴｉの一部をＭｎ，Ｆｅ，Ｓｂ，Ｎｂの少なく
とも一種の元素で置換したことを特徴とする強誘電体薄
膜。11. A ferroelectric thin film characterized in that Zr and / or Ti of lead zirconate titanate is partially replaced by at least one element of Mn, Fe, Sb and Nb.
／およびＴｉの含有量の１／１０以下をＭｎ，Ｆｅ，Ｓ
ｂ，Ｎｂの少なくとも一種の元素で置換したことを特徴
とする請求項１１記載の強誘電体薄膜。12. The method according to claim 12, wherein the content of Zr and / or Ti in the lead zirconate titanate is 1/10 or less of Mn, Fe, S.
The ferroelectric thin film according to claim 11, wherein the ferroelectric thin film is substituted with at least one element of b and Nb.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9153193A JPH111768A (en) | 1997-06-11 | 1997-06-11 | Target for ferroelectric thin film, its production and ferroelectric thin film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9153193A JPH111768A (en) | 1997-06-11 | 1997-06-11 | Target for ferroelectric thin film, its production and ferroelectric thin film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH111768A true JPH111768A (en) | 1999-01-06 |
Family
ID=15557087
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9153193A Pending JPH111768A (en) | 1997-06-11 | 1997-06-11 | Target for ferroelectric thin film, its production and ferroelectric thin film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH111768A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002038263A (en) * | 2000-07-25 | 2002-02-06 | Ulvac Japan Ltd | Sputtering device |
| JP2002324924A (en) * | 2001-04-24 | 2002-11-08 | Sony Corp | Method of manufacturing piezoelectric element |
| WO2003070641A1 (en) * | 2002-02-19 | 2003-08-28 | Matsushita Electric Industrial Co.,Ltd. | Piezoelectric body, manufacturing method thereof, piezoelectric element having the piezoelectric body, inject head, and inject type recording device |
| JP2007191351A (en) * | 2006-01-19 | 2007-08-02 | Seiko Epson Corp | Method for manufacturing insulating target material |
| KR20090071392A (en) * | 2007-12-27 | 2009-07-01 | 알박 머티리얼스 가부시키가이샤 | Method of forming lead zirconate titanate sintered compact, lead zirconate titanate sintered compact and lead zirconate titanate sputtering target |
| WO2011004679A1 (en) * | 2009-07-10 | 2011-01-13 | 日本碍子株式会社 | Piezoelectric body/electrostrictive body, piezoelectric/electrostrictive ceramic composition, piezoelectric element/electrostrictive element, and piezoelectric motor |
-
1997
- 1997-06-11 JP JP9153193A patent/JPH111768A/en active Pending
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002038263A (en) * | 2000-07-25 | 2002-02-06 | Ulvac Japan Ltd | Sputtering device |
| JP2002324924A (en) * | 2001-04-24 | 2002-11-08 | Sony Corp | Method of manufacturing piezoelectric element |
| WO2003070641A1 (en) * | 2002-02-19 | 2003-08-28 | Matsushita Electric Industrial Co.,Ltd. | Piezoelectric body, manufacturing method thereof, piezoelectric element having the piezoelectric body, inject head, and inject type recording device |
| US7048360B2 (en) | 2002-02-19 | 2006-05-23 | Matsushita Electric Industrial Co., Ltd. | Piezoelectric body, manufacturing method thereof, piezoelectric element having the piezoelectric body, inject head, and inject type recording device |
| JP2007191351A (en) * | 2006-01-19 | 2007-08-02 | Seiko Epson Corp | Method for manufacturing insulating target material |
| KR20090071392A (en) * | 2007-12-27 | 2009-07-01 | 알박 머티리얼스 가부시키가이샤 | Method of forming lead zirconate titanate sintered compact, lead zirconate titanate sintered compact and lead zirconate titanate sputtering target |
| JP2009155171A (en) * | 2007-12-27 | 2009-07-16 | Ulvac Material Kk | Method for producing lead zirconium titanate-based sintered body, lead zirconium titanate-based sintered body, and lead zirconium titanate-based sputtering target |
| US20120018664A1 (en) * | 2007-12-27 | 2012-01-26 | Ulvac, Inc. | Method of producing a lead zirconium titanate-based sintered body, lead zirconium titanate-based sintered body, and lead zirconium titanate-based sputtering target |
| WO2011004679A1 (en) * | 2009-07-10 | 2011-01-13 | 日本碍子株式会社 | Piezoelectric body/electrostrictive body, piezoelectric/electrostrictive ceramic composition, piezoelectric element/electrostrictive element, and piezoelectric motor |
| US8456066B2 (en) | 2009-07-10 | 2013-06-04 | Ngk Insulators, Ltd. | Piezoelectric / electrostrictive material, piezoelectric / electrostrictive ceramic composition, piezoelectric / electrostrictive element, and piezoelectric motor |
| JP5815404B2 (en) * | 2009-07-10 | 2015-11-17 | 日本碍子株式会社 | Piezoelectric body / electrostrictive body, piezoelectric / electrostrictive ceramic composition, piezoelectric element / electrostrictive element, and piezoelectric motor |
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