JP3597217B2 - Method of forming dielectric film - Google Patents
Method of forming dielectric film Download PDFInfo
- Publication number
- JP3597217B2 JP3597217B2 JP15230694A JP15230694A JP3597217B2 JP 3597217 B2 JP3597217 B2 JP 3597217B2 JP 15230694 A JP15230694 A JP 15230694A JP 15230694 A JP15230694 A JP 15230694A JP 3597217 B2 JP3597217 B2 JP 3597217B2
- Authority
- JP
- Japan
- Prior art keywords
- dielectric film
- film
- dielectric
- substrate
- forming
- 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.)
- Expired - Lifetime
Links
- 238000000034 method Methods 0.000 title claims description 20
- 239000001301 oxygen Substances 0.000 claims description 40
- 229910052760 oxygen Inorganic materials 0.000 claims description 40
- 239000000758 substrate Substances 0.000 claims description 27
- -1 oxygen ions Chemical class 0.000 claims description 23
- 238000000137 annealing Methods 0.000 claims description 20
- 229910002367 SrTiO Inorganic materials 0.000 claims description 16
- 238000004544 sputter deposition Methods 0.000 claims description 7
- 238000005229 chemical vapour deposition Methods 0.000 claims description 6
- 229910015802 BaSr Inorganic materials 0.000 claims description 4
- 229910013641 LiNbO 3 Inorganic materials 0.000 claims description 3
- 230000015572 biosynthetic process Effects 0.000 claims description 3
- 239000010408 film Substances 0.000 description 110
- 239000013078 crystal Substances 0.000 description 27
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 17
- 238000005468 ion implantation Methods 0.000 description 11
- 239000000463 material Substances 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 9
- 239000007789 gas Substances 0.000 description 9
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 238000001704 evaporation Methods 0.000 description 3
- VEALVRVVWBQVSL-UHFFFAOYSA-N strontium titanate Chemical compound [Sr+2].[O-][Ti]([O-])=O VEALVRVVWBQVSL-UHFFFAOYSA-N 0.000 description 3
- 239000010409 thin film Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 229910052454 barium strontium titanate Inorganic materials 0.000 description 2
- 238000002513 implantation Methods 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 229910052746 lanthanum Inorganic materials 0.000 description 2
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- WSMQKESQZFQMFW-UHFFFAOYSA-N 5-methyl-pyrazole-3-carboxylic acid Chemical compound CC1=CC(C(O)=O)=NN1 WSMQKESQZFQMFW-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 229910002113 barium titanate Inorganic materials 0.000 description 1
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004581 coalescence Methods 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- NKZSPGSOXYXWQA-UHFFFAOYSA-N dioxido(oxo)titanium;lead(2+) Chemical compound [Pb+2].[O-][Ti]([O-])=O NKZSPGSOXYXWQA-UHFFFAOYSA-N 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 1
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 1
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000003980 solgel method Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
- H01L21/02112—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer
- H01L21/02172—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing at least one metal element, e.g. metal oxides, metal nitrides, metal oxynitrides or metal carbides
- H01L21/02197—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing at least one metal element, e.g. metal oxides, metal nitrides, metal oxynitrides or metal carbides the material having a perovskite structure, e.g. BaTiO3
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02225—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer
- H01L21/0226—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process
- H01L21/02263—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase
- H01L21/02266—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase deposition by physical ablation of a target, e.g. sputtering, reactive sputtering, physical vapour deposition or pulsed laser deposition
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02225—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer
- H01L21/0226—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process
- H01L21/02263—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase
- H01L21/02271—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02296—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer
- H01L21/02318—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer post-treatment
- H01L21/02337—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer post-treatment treatment by exposure to a gas or vapour
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02296—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer
- H01L21/02318—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer post-treatment
- H01L21/02345—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer post-treatment treatment by exposure to radiation, e.g. visible light
- H01L21/02351—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer post-treatment treatment by exposure to radiation, e.g. visible light treatment by exposure to corpuscular radiation, e.g. exposure to electrons, alpha-particles, protons or ions
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Internal Circuitry In Semiconductor Integrated Circuit Devices (AREA)
- Formation Of Insulating Films (AREA)
- Physical Vapour Deposition (AREA)
- Electrodes Of Semiconductors (AREA)
Description
【０００１】
【産業上の利用分野】
本発明は、誘電体膜の成膜方法に関し、更に詳しくは、高い比誘電率を得るための誘電体膜の成膜方法に関する。
【０００２】
【従来の技術】
従来、ＳｒＴｉＯ３（チタン酸ストロンチウム）、（ＢａＳｒ）ＴｉＯ３（チタン酸ストロンチウム バリウム）等の誘電体膜を基板上に成膜する際には、例えばＳｒＴｉＯ３の場合は４００℃以上、（ＢａＳｒ）ＴｉＯ３の場合は５００℃以上の基板温度で成膜する等、該誘電体膜の材料がペロブスカイト構造の結晶性を得る温度以上の基板温度で誘電体膜を成膜することが一般的に行われていた。
【０００３】
【発明が解決しようとする課題】
しかしながら、前記成膜方法の場合は、広く知られているように誘電体膜の膜厚がある程度十分に厚くしないと、大きな比誘電率が得られない。
【０００４】
これは基板上に形成された誘電体膜の初期層の結晶性が悪く、また結晶粒径が小さいためであると考えられている。
言い換えれば誘電体膜が基板界面から粒径が十分な大きさの結晶粒が得られれば比較的膜厚が薄くても高い比誘電率が得られることになる。
【０００５】
本発明は従来の誘電体膜の成膜方法における問題点を解消するもので、基板上に成膜される誘電体膜において、基板界面近傍から大きな結晶粒を形成し、従って、比較的薄い膜厚でも高い比誘電率が得られる誘電体膜の成膜方法を提供することを目的とする。
【０００６】
【課題を解決するための手段】
本発明の誘電体膜の成膜方法は、基板上に酸化物系の誘電体膜を形成する成膜方法において、ペロブスカイト構造を有する誘電体膜をスパッタリング法またはＣＶＤ法にて成膜後、１×１０ 12 ａｔｏｍ／ｃｍ 2 から３×１０ 16 ａｔｏｍ／ｃｍ 2 の酸素イオンを誘電体膜に注入し、かつ該誘電体膜を温度２００℃以上でアニールすることを特徴とする。
【０００７】
また、前記誘電体膜は、ＳｒＴｉＯ3、ＢａＴｉＯ3、（ＢａＳｒ）ＴｉＯ3、ＬｉＮｂＯ3、ＬｉＴａＯ3、ＰｂＴｉＯ3、（ＰｂＬａ）ＴｉＯ3、Ｐｂ（ＺｒＴｉ）Ｏ3、（ＰｂＬａ）（ＺｒＴｉ）Ｏ3から成る誘電体膜であってもよい。
【０００８】
【作用】
本発明では、スパッタリング法またはＣＶＤ法にて基板上に誘電体膜を成膜した後、酸素イオンを誘電体膜に注入する。
【０００９】
基板上に成膜された誘電体膜に酸素イオンを注入することによって、結晶粒界がつぶされ、結晶粒と結晶粒の境界がなくなる。
【００１０】
その後、該誘電体膜を高温でアニールすると結晶粒と結晶粒の境界が不明瞭のために、隣接する結晶粒と結晶粒が吸収合体されやすく次第に大きくなり、その結果、基板界面近傍付近から比較的大きな結晶粒が得られるので、誘電体膜全体の比誘電率は従来の成膜方法で得られた誘電体膜に比べて高い値を示すようになる。
【００１１】
【実施例】
本発明の誘電体膜の成膜方法により成膜された誘電体膜が比較的薄い膜厚でも大きな比誘電率が得られるのは次の理由による。
【００１２】
即ち、基板上に薄膜を形成する際、従来から広く知られているように、その初期において核が形成され、成膜時間の経過と共に、次第にその核が成長し、島状構造となり、その後膜厚がおおよそ１０ｎｍ位でそれらの島状構造が互いに繋がり連続膜となる。
【００１３】
この時、夫々の島状構造の物は結晶成長方位が全く同じではないので、夫々が繋がった際、その境界は一般に結晶粒界となる。
この時の結晶粒の粒径は非常に小さく、一般に１０ｎｍ以下である。
【００１４】
その後、薄膜の成長が続けられると、これらの小さな結晶のうちいくつかが柱状に成長を続け、次第に大きな結晶となっていく。
【００１５】
ペロブスカイト構造を有する誘電体膜においては、その結晶粒が大きい程、高い比誘電率を示すことができるので、誘電体膜の膜厚の増大と共に結晶粒径が大きくなり、従って比誘電率も大きくなっていく。
【００１６】
このことから誘電体膜の膜厚が成膜初期からおおよそ１０ｎｍ位の範囲においても結晶粒径を大きくすることが出来れば、全体として高い比誘電率を示すようになる。
【００１７】
本発明において、誘電体膜にアニールを行う際の温度を２００℃以上としたのは、それ以下の温度では粒の吸収合体が進行せず、粒成長が起こらないからである。
【００１８】
また、誘電体膜中に注入する酸素イオン量を１×１０１２ａｔｏｍ／ｃｍ２から３×１０１６ａｔｏｍ／ｃｍ２としたのは、酸素イオン量が１×１０１２ａｔｏｍ／ｃｍ２に満たない場合は、結晶粒界をつぶす効果が弱いからであり、また、酸素イオン量が３×１０１６ａｔｏｍ／ｃｍ２を超えた場合は、膜中に酸素イオンが多数残留し、アニールの際に酸素ガスとして膜中から抜け出し、膜が欠陥だらけとなるからである。
【００１９】
以下に本発明の具体的実施例を比較例と共に説明する。
【００２０】
実施例１
５インチ径のＳｉ（ケイ素）ウェハー上に下部電極としてＰｔ（白金）電極を形成したものを基板として用いた。
【００２１】
この基板をＳｒＴｉＯ３（チタン酸ストロンチウム）ターゲットを備えたスパッタリング装置内に設置し、高周波出力５００ＷのＲＦパワーを印加して、下部電極上に膜厚６０ｎｍのＳｒＴｉＯ３誘電体膜を成膜した。
【００２２】
尚、スパッタ時の基板温度は３５０℃とし、スパッタ雰囲気ガスの圧力はＡｒ（アルゴン）ガス０．５Ｐａ、Ｏ２（酸素）ガス０．１Ｐａとした。
【００２３】
この基板をイオン注入装置内に移送し、加熱することなく、誘電体膜中にＯ２（酸素）イオンを２０ｋｅＶの加速エネルギーで５×１０１４ａｔｏｍ／ｃｍ２注入した。
【００２４】
続いて、この基板をアニール装置内に移送し、Ｏ２（酸素）ガス雰囲気中で、４５０℃で、１時間アニール処理を行った後、基板をアニール装置内より取り出した。
【００２５】
次に、この誘電体膜上に上部電極としてＰｔ（白金）電極を蒸着法により形成した。
【００２６】
尚、下部電極並びに上部電極の厚さは夫々１００ｎｍとした。
【００２７】
そして、下部電極と上部電極間のＳｒＴｉＯ３誘電体膜の比誘電率をインピーダンス測定器（ヒューレッドパッカー社製、ＨＰ４２８４Ａ）（ＬＣＲメータ）を用いて、測定周波数１ｋＨｚで測定したところ２５０であった。
【００２８】
比較例１
前記実施例１と同様の方法で基板の下部電極上にに膜厚６０ｎｍのＳｒＴｉＯ３誘電体膜を成膜した後、該誘電体膜への酸素イオン注入は行わなかった。
【００２９】
次に、前記実施例１と同様の方法でＯ２（酸素）ガス雰囲気中で、４５０℃で、１時間アニール処理を行った後、誘電体膜上に上部電極を蒸着法により形成した。そして、前記実施例１と同様の方法で下部電極と上部電極間のＳｒＴｉＯ３誘電体膜の比誘電率を測定したところ、９０であった。
【００３０】
比較例２
前記実施例１と同様の方法で誘電体膜を成膜した後、該誘電体膜に酸素イオンを注入（注入量５×１０１４ａｔｏｍ／ｃｍ２）した。
【００３１】
次に、前記実施例１と同様の方法でＯ２（酸素）ガス雰囲気中で、１５０℃で、５時間アニール処理を行った後、誘電体膜上に上部電極を蒸着法により形成した。そして、前記実施例１と同様の方法で下部電極と上部電極間のＳｒＴｉＯ３誘電体膜の比誘電率を測定したところ、１００であった。
【００３２】
実施例２
前記実施例１と同様の方法で誘電体膜を成膜した後、誘電体膜に注入する酸素イオン量を１×１０１０ａｔｏｍ／ｃｍ２から１×１０１８ａｔｏｍ／ｃｍ２まで種々変化させて、酸素イオン注入量の異なる誘電体膜を得た。
【００３３】
次に、酸素イオン注入量が種々異なる誘電体膜に前記実施例１と同様の方法でアニール処理を行った後、誘電体膜上に上部電極を形成した。
【００３４】
そして、前記実施例１と同様の方法で下部電極と上部電極間の酸素イオン注入量の異なる各ＳｒＴｉＯ３誘電体膜の比誘電率を夫々測定し、酸素イオン注入量と得られた比誘電率との関係を図１に示す。
【００３５】
図１から明らかなように、酸素イオン注入量が１×１０１１ａｔｏｍ／ｃｍ２以下では比誘電率は１００程度と低い値であったが、酸素イオン注入量が１×１０１２ａｔｏｍ／ｃｍ２以上、３×１０１６ａｔｏｍ／ｃｍ２以下の範囲では比誘電率は１７０〜２６０の値が得られた。また、イオン注入量が１×１０１７ａｔｏｍ／ｃｍ２以上で酸素イオンを注入した場合、上下電極の間に電界を印加した際、誘電体膜に電流が流れてしまい誘電率を測定することが出来なかった。
【００３６】
実施例１では誘電体膜中に酸素イオンが注入されているので、そのため下部電極上に成膜された誘電体膜の初期層付近に生じている小さな誘電体膜の結晶粒の粒界を不明瞭な形に潰してしまう。その後アニール処理を行うことにより結晶粒と結晶粒とが吸収合体しやすくなっているため結晶粒が大きく成長し、高い比誘電率が得られる。
【００３７】
比較例１では誘電体膜中に酸素イオンが注入されていないので、下部電極近傍の誘電体膜の小さな結晶粒は、その後アニール処理を行っても結晶粒はほとんど大きくならず、比誘電率は低いままである。
【００３８】
比較例２では誘電体膜中に酸素イオンが注入されているので、下部電極上に成膜された誘電体膜の初期層付近には小さな誘電体膜の結晶粒の粒界は不明瞭な形に潰れているが、その後のアニール処理温度が低いため、結晶粒と結晶粒の合体成長が進行せず、比誘電率は低いままである。
【００３９】
実施例２では誘電体膜中に注入する酸素イオン量が１×１０１１ａｔｏｍ／ｃｍ２以下の場合は注入量が少ないため、結晶粒の粒界を潰す効果が不十分で、その後アニール処理を行っても粒界が残っているため結晶が大きく成長していかない。また、注入する酸素イオン量が１×１０１７ａｔｏｍ／ｃｍ２以上の場合は誘電体膜中に過剰の酸素が多量に入っているため、アニール処理を行った際、誘電体膜中から酸素がガス状になって抜けてしまうので、誘電体膜が疎で粗い膜質になって、本来の絶縁性が失われてしまい、上下電極が短絡してしまう。
【００４０】
従って、実施例１並びに実施例２から明らかなように、成膜された誘電体膜に酸素イオンをイオン量１×１０１２ａｔｏｍ／ｃｍ２から３×１０１６ａｔｏｍ／ｃｍ２の範囲で注入した後、温度４５０℃（温度２００℃以上）でアニール処理を施すことにより高い比誘電率が得られることが確認された。これに対し、酸素イオン注入を行わなかった比較例１、並びに酸素イオン注入は行ったがアニール処理時の温度が１５０℃と低かった比較例２では比誘電率は１００以下と低かった。
【００４１】
実施例３〜１０
誘電体膜材料としてＢａＴｉＯ３（チタン酸バリウム）、（Ｂａ０．５Ｓｒ０．５）ＴｉＯ３（チタン酸ストロンチウムバリウム）、ＬｉＮｂＯ３（ニオブ酸リチウム）、ＬｉＴａＯ３（タンタル酸リチウム）、ＰｂＴｉＯ３（チタン酸鉛）、（Ｐｂ０．８Ｌａ０．２）ＴｉＯ３（チタン酸鉛ランタン）、Ｐｂ（Ｚｒ０．５Ｔｉ０．５）Ｏ３（ジルコン酸チタン酸鉛）、（Ｐｂ０．８Ｌａ０．２）（Ｚｒ０．５Ｔｉ０．５）Ｏ３（ジルコン酸チタン酸鉛ランタン）を用い、また、基板上への誘電体膜の成膜時の温度、注入酸素イオン量、アニール処理時の温度を表１に示す条件とした以外は前記実施例１と同様の方法で膜材料の異なる誘電体膜を得た。
【００４２】
そして、前記実施例１と同様の方法で下部電極と上部電極間の膜材料の異なる誘電体膜の比誘電率を夫々測定し、その結果を表１に示す。
【００４３】
【表１】
比較例３〜１０
前記実施例３〜１０と同様の方法で基板上に膜厚６０ｎｍの膜材料の異なる誘電体膜を成膜した後、各誘電体膜への酸素イオン注入は行わなかった。
【００４５】
次に、前記実施例３〜１０と同様の方法で膜材料の異なる誘電体膜にＯ２（酸素）ガス雰囲気中で、夫々アニール処理を行った後、各誘電体膜上に上部電極を蒸着法により形成した。
【００４６】
そして、前記実施例１と同様の方法で下部電極と上部電極間の膜材料の異なる誘電体膜の比誘電率を夫々測定し、その結果を表２に示す。
【００４７】
【表２】
表１並びに表２より明らかなように、実施例３〜１０の比誘電率は誘電体膜が同一材料の場合の比較例３〜１０の比誘電率に比して夫々大きくなっていることが確認された。
【００４９】
実施例１１
誘電体膜へのアニール処理時の温度を２００℃、３００℃、３５０℃、４００℃、５００℃、５５０℃、６００℃とした以外は前記実施例と同様の方法で基板上に膜厚６０ｎｍのＳｒＴｉＯ３誘電体膜を成膜した。
【００５０】
そして、前記実施例１と同様の方法で下部電極と上部電極間のＳｒＴｉＯ３誘電体膜の比誘電率を測定したところ、アニール処理時の温度２００℃の場合の比誘電率は１８０であり、温度３００℃の場合の比誘電率は２１０であり、温度３５０℃の場合の比誘電率は２４０であり、温度４００℃の場合の比誘電率は２５０であり、温度５００℃の場合の比誘電率は２５０であり、温度５５０℃の場合の比誘電率は２７０であり、温度６００℃の場合の比誘電率は２６０であった。
【００５１】
実施例１１から明らかなように酸素イオン注入した後、アニール処理を行う際の温度を２００℃以上とすることにより大きな比誘電率が得られることが確認された。
【００５２】
実施例１２
本実施例では誘電体膜を成膜する方法としてＣＶＤ（Ｃｈｅｍｉｃａｌ Ｖａｐｏｒ Ｄｅｐｏｓｉｔｉｏｎ）法を用いて成膜するものである。
【００５３】
ＳｒＴｉＯ３（チタン酸ストロンチウム）誘電体膜の成膜をＳｒ（ＤＰＭ）２とＴｉ（Ｏ−ｉ−Ｃ３Ｈ７）４を原料として基板温度４００℃、反応圧力２００Ｐａで行い、基板の下部電極上に膜厚６０ｎｍのＳｒＴｉＯ３誘電体膜を成膜した。
【００５４】
そして前記実施例１と同様の方法でイオン注入、アニール処理を行った後、下部電極と上部電極間のＳｒＴｉＯ３誘電体膜の比誘電率を測定したところ、２８０であった。
【００５５】
前記実施例では誘電体膜を成膜する方法としてスパッタリング法或いはＣＶＤ法を用いたが、同一材料の誘電体膜を形成する方法として膜材料をゾル−ゲル法等の塗布法を用いて成膜するようにしてもよい。
【００５６】
【発明の効果】
本発明によるときは、基板上に誘電体膜を成膜した後、膜中に酸素イオンを注入するようにしたので、基板上に成膜された誘電体膜の初期層に成長した小さな結晶粒の粒界が潰され、その後、誘電体膜に温度２００℃以上のアニール処理を施すようにしたので、もとの結晶粒が吸収合体しながら成長するため、誘電体膜の初期層から大きな結晶粒が得られるので、高い比誘電率の誘電体膜を成膜することが出来る等の効果がある。
【図面の簡単な説明】
【図１】本発明の１実施例の誘電体膜に注入する酸素イオン注入量と成膜された誘電体膜の比誘電率との関係を表す特性線図。[0001]
[Industrial applications]
The present invention relates to a method for forming a dielectric film, and more particularly, to a method for forming a dielectric film for obtaining a high relative dielectric constant.
[0002]
[Prior art]
Conventionally, when a dielectric film such as SrTiO 3 (strontium titanate) or (BaSr) TiO 3 (barium strontium titanate) is formed on a substrate, for example, in the case of SrTiO 3 , 400 ° C. or more, (BaSr) In the case of TiO 3 , it is common practice to form a dielectric film at a substrate temperature higher than the temperature at which the material of the dielectric film obtains the crystallinity of the perovskite structure, such as forming the film at a substrate temperature of 500 ° C. or more. Had been
[0003]
[Problems to be solved by the invention]
However, in the case of the film forming method, as is widely known, a large relative dielectric constant cannot be obtained unless the thickness of the dielectric film is sufficiently large to some extent.
[0004]
It is considered that this is because the crystallinity of the initial layer of the dielectric film formed on the substrate is poor and the crystal grain size is small.
In other words, if crystal grains having a sufficiently large particle size are obtained from the interface between the dielectric film and the substrate, a high relative dielectric constant can be obtained even if the film thickness is relatively small.
[0005]
The present invention solves the problems in the conventional method of forming a dielectric film. In a dielectric film formed on a substrate, large crystal grains are formed from near a substrate interface, and thus a relatively thin film is formed. It is an object of the present invention to provide a method for forming a dielectric film capable of obtaining a high relative dielectric constant even with a thickness.
[0006]
[Means for Solving the Problems]
Method of forming a dielectric film of the present invention is a film forming method of forming a dielectric film of oxide on the substrate, after forming a dielectric film having a perovskite structure by a sputtering method or a CVD method, 1 × injected from 10 12 atom / cm 2 to 3 × the 10 16 atom / cm 2 oxygen ions to the dielectric film, and wherein the annealing the dielectric film at a
[0007]
The dielectric film is made of SrTiO 3 , BaTiO 3 , (BaSr) TiO 3 , LiNbO 3 , LiTaO 3 , PbTiO 3 , (PbLa) TiO 3 , Pb (ZrTi) O 3 , (PbLa) (ZrTi) O 3 May be used.
[000 8 ]
[Action]
In the present invention, after a dielectric film is formed on a substrate by a sputtering method or a CVD method, oxygen ions are implanted into the dielectric film.
[0009]
By implanting oxygen ions into the dielectric film formed on the substrate, crystal grain boundaries are crushed, and boundaries between crystal grains are eliminated.
[0010]
Thereafter, when the dielectric film is annealed at a high temperature, the boundaries between the crystal grains are not clear, and the adjacent crystal grains are likely to be absorbed and coalesced, and gradually become larger. Since relatively large crystal grains are obtained, the relative dielectric constant of the entire dielectric film shows a higher value than that of a dielectric film obtained by a conventional film forming method.
[0011]
【Example】
The reason why a large relative dielectric constant can be obtained even when the dielectric film formed by the method of forming a dielectric film according to the present invention has a relatively small thickness is as follows.
[0012]
That is, when a thin film is formed on a substrate, a nucleus is formed in the initial stage, and the nucleus gradually grows with the elapse of the film formation time to form an island-like structure, and then the film is formed. When the thickness is about 10 nm, those island-like structures are connected to each other to form a continuous film.
[0013]
At this time, since the crystal growth directions of the respective island-shaped structures are not exactly the same, when they are connected, the boundary generally becomes a crystal grain boundary.
At this time, the grain size of the crystal grains is very small, generally 10 nm or less.
[0014]
Thereafter, as the growth of the thin film is continued, some of these small crystals continue to grow in a columnar shape, and gradually become larger crystals.
[0015]
In a dielectric film having a perovskite structure, the larger the crystal grain, the higher the relative dielectric constant can be shown. Therefore, as the thickness of the dielectric film increases, the crystal grain size increases, and therefore the relative dielectric constant also increases. It is becoming.
[0016]
Thus, if the crystal grain size can be increased even when the thickness of the dielectric film is in the range of about 10 nm from the initial stage of the film formation, a high relative dielectric constant will be exhibited as a whole.
[0017]
In the present invention, the temperature at which the dielectric film is annealed is set to 200 ° C. or higher because at a temperature lower than that, the absorption and coalescence of the grains does not proceed and the grain growth does not occur.
[0018]
Also, the reason why the amount of oxygen ions implanted into the dielectric film is set to 1 × 10 12 atoms / cm 2 to 3 × 10 16 atoms / cm 2 is that the amount of oxygen ions is less than 1 × 10 12 atoms / cm 2 . In this case, the effect of crushing the crystal grain boundaries is weak, and when the amount of oxygen ions exceeds 3 × 10 16 atoms / cm 2 , many oxygen ions remain in the film, and oxygen ions are generated during annealing. This is because the gas escapes from the film as a gas and the film is full of defects.
[0019]
Hereinafter, specific examples of the present invention will be described together with comparative examples.
[0020]
Example 1
A substrate formed by forming a Pt (platinum) electrode as a lower electrode on a 5-inch diameter Si (silicon) wafer was used as a substrate.
[0021]
This substrate was placed in a sputtering apparatus equipped with an SrTiO 3 (strontium titanate) target, and RF power with a high frequency output of 500 W was applied to form a 60 nm thick SrTiO 3 dielectric film on the lower electrode.
[0022]
The substrate temperature during sputtering was 350 ° C., and the pressure of the sputtering atmosphere gas was 0.5 Pa for Ar (argon) gas and 0.1 Pa for O 2 (oxygen) gas.
[0023]
The substrate was transferred into an ion implanter, and without heating, 5 × 10 14 atoms / cm 2 of O 2 (oxygen) ions were implanted into the dielectric film at an acceleration energy of 20 keV.
[0024]
Subsequently, the substrate was transferred into an annealing apparatus, annealed at 450 ° C. for 1 hour in an O 2 (oxygen) gas atmosphere, and then the substrate was taken out from the annealing apparatus.
[0025]
Next, a Pt (platinum) electrode was formed as an upper electrode on the dielectric film by an evaporation method.
[0026]
Note that the thickness of each of the lower electrode and the upper electrode was 100 nm.
[0027]
Then, the relative dielectric constant of the SrTiO 3 dielectric film between the lower electrode and the upper electrode was measured at a measurement frequency of 1 kHz using an impedance measuring instrument (HP4284A, manufactured by Hewlett-Packer Co., Ltd.) (LCR meter) and found to be 250. .
[0028]
Comparative Example 1
After a 60 nm thick SrTiO 3 dielectric film was formed on the lower electrode of the substrate in the same manner as in Example 1, oxygen ions were not implanted into the dielectric film.
[0029]
Next, an annealing process was performed at 450 ° C. for 1 hour in an O 2 (oxygen) gas atmosphere in the same manner as in Example 1, and then an upper electrode was formed on the dielectric film by an evaporation method. Then, the relative dielectric constant of the SrTiO 3 dielectric film between the lower electrode and the upper electrode was measured in the same manner as in Example 1 to be 90.
[0030]
Comparative Example 2
After a dielectric film was formed in the same manner as in Example 1, oxygen ions were implanted into the dielectric film (implantation amount: 5 × 10 14 atoms / cm 2 ).
[0031]
Next, in the same manner as in Example 1, annealing was performed at 150 ° C. for 5 hours in an O 2 (oxygen) gas atmosphere, and then an upper electrode was formed on the dielectric film by an evaporation method. Then, the relative dielectric constant of the SrTiO 3 dielectric film between the lower electrode and the upper electrode was measured in the same manner as in Example 1 to be 100.
[0032]
Example 2
After forming the dielectric film in the same manner as in Example 1, while varying the amount of oxygen ions to be implanted into the dielectric film from 1 × 10 10 atom / cm 2 to 1 × 10 18 atom / cm 2 Then, dielectric films having different oxygen ion implantation amounts were obtained.
[0033]
Next, an annealing process was performed on the dielectric films having various oxygen ion implantation amounts in the same manner as in the first embodiment, and then an upper electrode was formed on the dielectric films.
[0034]
Then, the relative permittivity of each SrTiO 3 dielectric film having a different oxygen ion implantation amount between the lower electrode and the upper electrode was measured in the same manner as in Example 1, and the oxygen ion implantation amount and the obtained relative permittivity were measured. 1 is shown in FIG.
[0035]
As apparent from FIG. 1, the relative dielectric constant was as low as about 100 when the oxygen ion implantation amount was 1 × 10 11 atom / cm 2 or less, but the oxygen ion implantation amount was 1 × 10 12 atom / cm 2. As described above, in the range of 3 × 10 16 atoms / cm 2 or less, a relative dielectric constant of 170 to 260 was obtained. Further, when oxygen ions are implanted at an ion implantation amount of 1 × 10 17 atoms / cm 2 or more, when an electric field is applied between the upper and lower electrodes, a current flows through the dielectric film and the dielectric constant may be measured. I could not do it.
[0036]
In Example 1, since oxygen ions were implanted into the dielectric film, the grain boundaries of crystal grains of the small dielectric film formed near the initial layer of the dielectric film formed on the lower electrode were not affected. Crush it into a clear shape. Thereafter, by performing an annealing treatment, the crystal grains are easily absorbed and united, so that the crystal grains grow large and a high relative dielectric constant is obtained.
[0037]
In Comparative Example 1, since oxygen ions were not implanted into the dielectric film, the small crystal grains of the dielectric film near the lower electrode hardly became large even after the subsequent annealing treatment, and the relative dielectric constant was low. Stays low.
[0038]
In Comparative Example 2, since oxygen ions were implanted into the dielectric film, the grain boundaries of small dielectric film crystal grains near the initial layer of the dielectric film formed on the lower electrode were indistinct. However, since the subsequent annealing temperature is low, the combined growth of crystal grains does not proceed, and the relative dielectric constant remains low.
[0039]
In Example 2, when the amount of oxygen ions implanted into the dielectric film is 1 × 10 11 atoms / cm 2 or less, the implantation amount is small, and the effect of crushing the grain boundaries of the crystal grains is insufficient. The crystal does not grow greatly because the grain boundaries remain even if the process is performed. When the amount of oxygen ions to be implanted is 1 × 10 17 atoms / cm 2 or more, a large amount of excess oxygen is contained in the dielectric film. Therefore, when the annealing treatment is performed, oxygen is removed from the dielectric film. Since the dielectric film becomes gaseous and escapes, the dielectric film becomes sparse and coarse, loses its original insulation properties, and short-circuits the upper and lower electrodes.
[0040]
Therefore, as is clear from Examples 1 and 2, oxygen ions were implanted into the formed dielectric film in an amount of 1 × 10 12 atoms / cm 2 to 3 × 10 16 atoms / cm 2 . Thereafter, it was confirmed that a high relative dielectric constant can be obtained by performing annealing at a temperature of 450 ° C. (200 ° C. or higher). In contrast, in Comparative Example 1 in which oxygen ion implantation was not performed, and in Comparative Example 2 in which oxygen ion implantation was performed but the temperature during annealing was as low as 150 ° C., the relative dielectric constant was as low as 100 or less.
[0041]
Examples 3 to 10
BaTiO 3 as a dielectric film material (barium titanate), (Ba 0. 5 Sr 0. 5) TiO 3 ( barium strontium titanate), LiNbO 3 (lithium niobate), LiTaO 3 (lithium tantalate), PbTiO 3 (lead titanate), (Pb 0. 8 La 0. 2) TiO 3 ( lead lanthanum titanate), Pb (Zr 0. 5 Ti 0. 5) O 3 ( lead zirconate titanate), (Pb 0. 8 La 0. 2) (Zr 0. 5 Ti 0. 5) O 3 ( with lead lanthanum zirconate titanate), the temperature during the deposition of the dielectric film on the substrate, implanting oxygen ion amount, A dielectric film having a different film material was obtained in the same manner as in Example 1 except that the temperature during the annealing treatment was set to the conditions shown in Table 1.
[0042]
Then, the relative dielectric constants of dielectric films having different film materials between the lower electrode and the upper electrode were measured in the same manner as in Example 1, and the results are shown in Table 1.
[0043]
[Table 1]
Comparative Examples 3 to 10
After a dielectric film of a different film material with a thickness of 60 nm was formed on the substrate in the same manner as in Examples 3 to 10, oxygen ions were not implanted into each dielectric film.
[0045]
Next, in the same manner as in Examples 3 to 10, the dielectric films having different film materials were respectively annealed in an O 2 (oxygen) gas atmosphere, and then an upper electrode was deposited on each of the dielectric films. It was formed by a method.
[0046]
Then, the relative dielectric constants of dielectric films having different film materials between the lower electrode and the upper electrode were measured in the same manner as in Example 1, and the results are shown in Table 2.
[0047]
[Table 2]
As is clear from Tables 1 and 2, the relative dielectric constants of Examples 3 to 10 are larger than those of Comparative Examples 3 to 10 when the dielectric films are made of the same material. confirmed.
[0049]
Example 11
A 60 nm-thickness film was formed on a substrate in the same manner as in the above embodiment except that the temperature at the time of annealing the dielectric film was set at 200 ° C., 300 ° C., 350 ° C., 400 ° C., 500 ° C., 550 ° C., and 600 ° C. An SrTiO 3 dielectric film was formed.
[0050]
When the relative dielectric constant of the SrTiO 3 dielectric film between the lower electrode and the upper electrode was measured in the same manner as in Example 1, the relative dielectric constant at the time of annealing at a temperature of 200 ° C. was 180, The relative permittivity at a temperature of 300 ° C. is 210, the relative permittivity at a temperature of 350 ° C. is 240, the relative permittivity at a temperature of 400 ° C. is 250, and the relative permittivity at a temperature of 500 ° C. The dielectric constant was 250, the relative dielectric constant at a temperature of 550 ° C. was 270, and the relative dielectric constant at a temperature of 600 ° C. was 260.
[0051]
As is apparent from Example 11, it was confirmed that a large relative dielectric constant can be obtained by setting the temperature at which the annealing treatment is performed to 200 ° C. or higher after oxygen ion implantation.
[0052]
Example 12
In this embodiment, as a method for forming a dielectric film, a film is formed by using a CVD (Chemical Vapor Deposition) method.
[0053]
The SrTiO 3 (strontium titanate) dielectric film is formed at a substrate temperature of 400 ° C. and a reaction pressure of 200 Pa using Sr (DPM) 2 and Ti (OiC 3 H 7 ) 4 as raw materials, and a lower electrode of the substrate is formed. An SrTiO 3 dielectric film having a thickness of 60 nm was formed thereon.
[0054]
After ion implantation and annealing were performed in the same manner as in Example 1, the relative dielectric constant of the SrTiO 3 dielectric film between the lower electrode and the upper electrode was measured to be 280.
[0055]
In the above embodiment, a sputtering method or a CVD method is used as a method for forming a dielectric film. However, as a method for forming a dielectric film of the same material, a film material is formed using a coating method such as a sol-gel method. You may make it.
[0056]
【The invention's effect】
According to the present invention, after a dielectric film is formed on a substrate, oxygen ions are implanted into the film, so that small crystal grains grown in an initial layer of the dielectric film formed on the substrate are formed. The grain boundaries of the dielectric film are crushed, and then the dielectric film is subjected to an annealing treatment at a temperature of 200 ° C. or higher. Therefore, the original crystal grains grow while absorbing and coalescing. Since grains are obtained, there is an effect that a dielectric film having a high relative dielectric constant can be formed.
[Brief description of the drawings]
FIG. 1 is a characteristic diagram showing the relationship between the amount of oxygen ions implanted into a dielectric film according to one embodiment of the present invention and the relative dielectric constant of a formed dielectric film.
Claims (2)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15230694A JP3597217B2 (en) | 1994-07-04 | 1994-07-04 | Method of forming dielectric film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15230694A JP3597217B2 (en) | 1994-07-04 | 1994-07-04 | Method of forming dielectric film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0817764A JPH0817764A (en) | 1996-01-19 |
| JP3597217B2 true JP3597217B2 (en) | 2004-12-02 |
Family
ID=15537650
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15230694A Expired - Lifetime JP3597217B2 (en) | 1994-07-04 | 1994-07-04 | Method of forming dielectric film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3597217B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6258655B1 (en) * | 1999-03-01 | 2001-07-10 | Micron Technology, Inc. | Method for improving the resistance degradation of thin film capacitors |
| DE112010005548B4 (en) | 2010-05-11 | 2016-08-18 | Toyota Jidosha Kabushiki Kaisha | METHOD FOR DETERMINING THE AGR RATE OF A COMBUSTION ENGINE AND CONTROL DEVICE FOR A COMBUSTION ENGINE |
-
1994
- 1994-07-04 JP JP15230694A patent/JP3597217B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0817764A (en) | 1996-01-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE69805865T2 (en) | Manufacturing process of platinum layers with controlled preferred orientation using nitrogen | |
| US5397446A (en) | Method of forming a ferroelectric film | |
| JPH06502967A (en) | Voltage variable capacitor with amorphous dielectric film | |
| Mascot et al. | Very high tunability of BaSnxTi1-xO3 ferroelectric thin films deposited by sol-gel | |
| JP3597217B2 (en) | Method of forming dielectric film | |
| JPH07263570A (en) | Manufacture of dielectric device | |
| JPH08213560A (en) | Ferroelectric capacitor and its manufacture | |
| Kim et al. | Structural and electrical properties of excess PbO doped Pb (Zr0. 52Ti0. 48) O3 thin films using rf magnetron sputtering method | |
| JPH1093050A (en) | Thin-film capacitor and manufacture thereof | |
| Al-Shareef et al. | Electrical properties of Pb (Zr0. 53Ti0. 47) O3 thin film capacitors with modified RuO2 bottom electrodes | |
| Adikary et al. | Dielectric dispersion and tunability of sol-gel derived Ba x Sr 1− x TiO 3 thin films | |
| Lee et al. | Low-frequency dielectric responses of barium strontium titanate thin films with conducting perovskite LaNiO3 electrode | |
| JPH0380562A (en) | Manufacture of thin film capacitor | |
| JP2001189422A (en) | Method of manufacturing thin-film capacitor | |
| JP3267278B2 (en) | Method for manufacturing semiconductor device | |
| JPH0610926B2 (en) | Dielectric film manufacturing method | |
| JPH09153598A (en) | Dielectric thin film element and fabrication thereof | |
| US7157144B1 (en) | Giant remnant polarization in laser ablated SrBi2Nb2O9 thin films on Pt/TiO2/SiO2/Si substrates | |
| JPH0265111A (en) | Thin-film capacitor and manufacture thereof | |
| JPH0741944A (en) | Production of ferroelectric thin film and production of dielectric thin film | |
| JPH08330179A (en) | Ceramic capacitor | |
| Zhang et al. | Textured BST Thin Film on Silicon Substrate: Preparation and Its Applications for High Frequency Tunable Devices | |
| Ibrahim et al. | Characterization of niobium-doped lead titanate thin films | |
| JP3286218B2 (en) | Thin film dielectric element | |
| Ea-Kim et al. | Growth and characterization of radio-frequency magnetron sputtered lead zirconate titanate thin films deposited on< 111> Pt electrodes |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20040518 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20040712 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20040810 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20040908 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20070917 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100917 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130917 Year of fee payment: 9 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |