JP3098134B2 - Method for manufacturing oxide crystal film - Google Patents
Method for manufacturing oxide crystal filmInfo
- Publication number
- JP3098134B2 JP3098134B2 JP8966793A JP8966793A JP3098134B2 JP 3098134 B2 JP3098134 B2 JP 3098134B2 JP 8966793 A JP8966793 A JP 8966793A JP 8966793 A JP8966793 A JP 8966793A JP 3098134 B2 JP3098134 B2 JP 3098134B2
- Authority
- JP
- Japan
- Prior art keywords
- film
- oxide
- heat treatment
- pzt
- oxide crystal
- 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 - Fee Related
Links
- 239000013078 crystal Substances 0.000 title claims description 36
- 238000000034 method Methods 0.000 title claims description 27
- 238000004519 manufacturing process Methods 0.000 title claims description 13
- 238000010438 heat treatment Methods 0.000 claims description 56
- 229910052799 carbon Inorganic materials 0.000 claims description 30
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 27
- 239000000758 substrate Substances 0.000 claims description 25
- 239000000470 constituent Substances 0.000 claims description 14
- 238000003980 solgel method Methods 0.000 claims description 12
- 239000012298 atmosphere Substances 0.000 claims description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 9
- 239000001301 oxygen Substances 0.000 claims description 9
- 229910052760 oxygen Inorganic materials 0.000 claims description 9
- 239000011247 coating layer Substances 0.000 claims description 7
- 239000010408 film Substances 0.000 description 177
- 239000000203 mixture Substances 0.000 description 32
- 150000002500 ions Chemical class 0.000 description 15
- 238000001704 evaporation Methods 0.000 description 13
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 10
- 230000008020 evaporation Effects 0.000 description 10
- 229910052710 silicon Inorganic materials 0.000 description 10
- 239000010703 silicon Substances 0.000 description 10
- 239000011248 coating agent Substances 0.000 description 9
- 238000000576 coating method Methods 0.000 description 9
- 239000007789 gas Substances 0.000 description 9
- 238000002425 crystallisation Methods 0.000 description 8
- 230000008025 crystallization Effects 0.000 description 8
- 238000004458 analytical method Methods 0.000 description 7
- 238000004544 sputter deposition Methods 0.000 description 7
- 230000015572 biosynthetic process Effects 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 230000003247 decreasing effect Effects 0.000 description 5
- 230000015654 memory Effects 0.000 description 5
- 238000000682 scanning probe acoustic microscopy Methods 0.000 description 5
- 239000004065 semiconductor Substances 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 4
- -1 carbon ions Chemical class 0.000 description 4
- 239000010410 layer Substances 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 238000000151 deposition Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000004453 electron probe microanalysis Methods 0.000 description 3
- 238000005268 plasma chemical vapour deposition Methods 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 2
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 2
- 239000005977 Ethylene Substances 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 2
- 150000004703 alkoxides Chemical class 0.000 description 2
- 239000012300 argon atmosphere Substances 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 229910001882 dioxygen Inorganic materials 0.000 description 2
- 230000005621 ferroelectricity Effects 0.000 description 2
- 230000001965 increasing effect Effects 0.000 description 2
- 229910052745 lead Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 238000001552 radio frequency sputter deposition Methods 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 230000003746 surface roughness Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- 229910013641 LiNbO 3 Inorganic materials 0.000 description 1
- 238000001069 Raman spectroscopy Methods 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 238000010884 ion-beam technique Methods 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 238000000608 laser ablation Methods 0.000 description 1
- 238000002488 metal-organic chemical vapour deposition Methods 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000004528 spin coating Methods 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000007738 vacuum evaporation Methods 0.000 description 1
Landscapes
- Crystals, And After-Treatments Of Crystals (AREA)
- Chemical Vapour Deposition (AREA)
- Recrystallisation Techniques (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、酸化物結晶膜の製造方
法に関し、ことに本発明は、ＰｂＴｉＯ3 やＰＺＴ(Pb
(Zr1-XTix)O3) をはじめとする鉛系強誘電性酸化物材料
を用いる酸化物結晶膜の製造に有用である。The present invention relates to relates to a process for the preparation of crystalline oxide film, particularly the present invention, PbTiO 3 and PZT (Pb
It is useful for producing an oxide crystal film using a lead-based ferroelectric oxide material such as (Zr 1-X Ti x ) O 3 ).
【０００２】[0002]
【従来の技術及び発明が解決しようとする課題】ＰＺ
Ｔ、ＰｂＴｉＯ3 をはじめとする酸化物強誘電体結晶
は、その強誘電特性や電気光学特性を利用して不揮発性
メモリ、光変調器等多くの機能デバイスの開発に不可欠
な材料である。特に最近では、ＤＲＡＭ等の半導体メモ
リと組み合わせることで高密度で、かつ高速で動作する
不揮発性強誘電体メモリの研究開発が活発に行われてい
る。2. Description of the Related Art PZ
Oxide ferroelectric crystals such as T and PbTiO 3 are indispensable materials for developing many functional devices such as nonvolatile memories and optical modulators by utilizing their ferroelectric and electro-optical properties. In particular, recently, research and development of a nonvolatile ferroelectric memory which operates at a high density and at a high speed by being combined with a semiconductor memory such as a DRAM has been actively conducted.
【０００３】このようなデバイス開発には、残留自発分
極（Ｐｒ）が大きく、かつ抗電場（Ｅｃ）の小さい強誘
電体材料が不可欠であるばかりでなく、半導体プロセス
との整合性があり、かつ低駆動電圧（〜３Ｖ）で動作す
ることが要求されている。このため、現在これらの要求
に適した材料としてＰＺＴ、ＰｂＴｉＯ3 等が用いら
れ、高品質の結晶膜の開発が行われている。For the development of such a device, not only a ferroelectric material having a large residual spontaneous polarization (Pr) and a small coercive electric field (Ec) is indispensable, but also has compatibility with a semiconductor process, and It is required to operate at a low driving voltage (up to 3 V). For this reason, PZT, PbTiO 3, and the like are currently used as materials suitable for these requirements, and high-quality crystal films are being developed.
【０００４】ＰＺＴ(Pb(Zr1-XTix)O3) 等の強誘電性酸
化物の成膜方法として、真空蒸着法、スパッタ法、レー
ザアブレーション法、ＭＯＣＶＤ法、ゾル−ゲル法等各
種の方法が用いられている。そしてその結晶性を向上さ
せ、デバイスへの適用が可能な電気特性を得るため、通
常、酸素雰囲気中、６００℃以上の温度での熱処理が行
われている。As a method for forming a ferroelectric oxide such as PZT (Pb (Zr 1-X Ti x ) O 3 ), various methods such as vacuum evaporation, sputtering, laser ablation, MOCVD, and sol-gel methods are available. Is used. In order to improve the crystallinity and obtain electrical characteristics applicable to devices, heat treatment is usually performed in an oxygen atmosphere at a temperature of 600 ° C. or higher.
【０００５】一方、ＰＺＴ(Pb(Zr1-XTix)O3) の強誘電
特性は組成ｘに大きく依存する。このため、結晶膜の作
製においては、膜組成の制御が最も重要となる。しか
し、ＰＺＴの構成元素の中でＰｂは他の元素に比べて蒸
気圧が高いために、各種の成膜法において原料組成の調
整や各種製膜条件によって、膜組成は大きく左右され
る。例えば、結晶化させるための熱処理中にも膜中から
のＰｂの蒸発が起こるため、予め設定した組成からのず
れが生じてしまうことがある。また、Ｐｂが蒸発するこ
とによって膜表面の形状においても、激しい凹凸やピン
ホールが発生し、このような膜をメモリキャパシタとし
て用いる場合に、リーク電流の原因等のデバイス作製の
上で大きな問題となっている。このような問題は、膜厚
の薄膜化に伴い、その影響は増大することは明らかであ
ろう。On the other hand, the ferroelectric properties of PZT (Pb (Zr 1 -X Ti x ) O 3 ) greatly depend on the composition x. For this reason, control of the film composition is most important in producing a crystalline film. However, among the constituent elements of PZT, Pb has a higher vapor pressure than other elements, so that the film composition is greatly influenced by adjustment of the raw material composition and various film forming conditions in various film forming methods. For example, during the heat treatment for crystallization, Pb evaporates from the film, which may cause a deviation from a preset composition. Further, evaporation of Pb causes severe irregularities and pinholes in the shape of the film surface, and when such a film is used as a memory capacitor, there is a major problem in device fabrication such as a cause of a leak current. Has become. It is clear that such a problem has an increasing effect as the film thickness is reduced.
【０００６】そこで、熱処理時のＰｂの蒸発を抑え、膜
のストイキオメトリ組成を確保することを考慮した熱処
理方法として、ＲＴＡ（Rapid Thermal Anneal) 法が種
々検討されている。この方法は、熱処理温度までの昇温
および降温速度を速くし、かつ熱処理温度での保持時間
を短くすることで、できるだけ熱処理中のＰｂの蒸発量
を抑えようとするものである。しかし、現実にはこの方
法でもＰｂの蒸発を十分には抑制できず、膜中組成の変
化を生じさせてしまうという問題があった。[0006] Therefore, various RTA (Rapid Thermal Anneal) methods have been studied as heat treatment methods in consideration of suppressing the evaporation of Pb during heat treatment and ensuring the stoichiometric composition of the film. In this method, the rate of temperature rise and fall to the heat treatment temperature is increased, and the holding time at the heat treatment temperature is shortened, so that the amount of Pb evaporation during the heat treatment is suppressed as much as possible. However, in practice, there is a problem that even this method cannot sufficiently suppress the evaporation of Pb, causing a change in the composition in the film.
【０００７】実際、スパッタ法やゾル−ゲル法等により
作製したＰＺＴ膜の熱処理前後での膜組成をＸ線マイク
ロアナライザー（ＥＰＭＡ）とオージェ電子分光法（Ａ
ＥＳ）とにより分析すると、膜中のＺｒとＴｉとの含有
量には変化が認められないが、Ｐｂ量が大きく減少して
おり、特に膜表面に向かってのＰｂ組成の減少が顕著と
なっているという問題があった。[0007] Actually, the film composition of a PZT film produced by a sputtering method, a sol-gel method, etc. before and after a heat treatment is measured by an X-ray microanalyzer (EPMA) and an Auger electron spectroscopy (A).
ES), no change was found in the contents of Zr and Ti in the film, but the amount of Pb was greatly reduced, and the decrease of the Pb composition particularly toward the film surface became remarkable. There was a problem that.
【０００８】本発明は、上記課題を解決するためになさ
れたものであって、結晶化のための熱処理時の酸化物結
晶膜の構成元素の蒸発を抑制するか、あるいは該熱処理
により蒸発した酸化物結晶膜の構成元素を、熱処理した
後に補償することにより、酸化物結晶膜のストイキオメ
トリ組成を確保することができる酸化物結晶膜の製造方
法を提供しようとするものである。SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to suppress the evaporation of constituent elements of an oxide crystal film at the time of heat treatment for crystallization, or to reduce the oxidization caused by the heat treatment. It is an object of the present invention to provide a method for manufacturing an oxide crystal film that can secure the stoichiometric composition of the oxide crystal film by compensating for the constituent elements of the material crystal film after heat treatment.
【０００９】[0009]
【課題を解決するための手段】本発明によれば、基板上
に、酸化物膜を形成し、該酸化物膜の表面をダイヤモン
ド状炭素膜で被覆した後、熱処理する酸化物結晶膜の製
造方法が提供される。また、基板上に、酸化物膜を形成
し、熱処理により該酸化物膜を酸化物結晶膜にした後、
該酸化物結晶膜上に、該膜中の少なくとも１種の構成元
素を含有する被覆層をゾル−ゲル法により形成し、さら
に５００℃以下の温度で熱処理を行う酸化物結晶膜の製
造方法が提供される。According to the present invention, an oxide crystal film is formed on a substrate, and the surface of the oxide film is coated with a diamond-like carbon film and then heat-treated. A method is provided. An oxide film is formed over a substrate, and the oxide film is turned into an oxide crystal film by heat treatment.
A method for producing an oxide crystal film in which a coating layer containing at least one kind of constituent element in the film is formed on the oxide crystal film by a sol-gel method, and further subjected to a heat treatment at a temperature of 500 ° C. or less. Provided.
【００１０】本発明において使用される基板は、特に限
定されるものではなく、半導体基板、ガラス基板等を用
いることができるが、シリコン、ＧａＡｓ等の半導体基
板が好ましい。また、基板上に、例えば、絶縁膜や導電
材料等の所望の素子が形成されたものを用いることもで
きる。The substrate used in the present invention is not particularly limited, and a semiconductor substrate, a glass substrate and the like can be used, but a semiconductor substrate of silicon, GaAs or the like is preferable. Alternatively, a substrate on which a desired element such as an insulating film or a conductive material is formed can be used.
【００１１】本発明における酸化物膜とは、蒸気圧の高
い元素、例えばＰｂ、Ｌｉ等を含有する酸化物膜であ
り、具体的には、ＰＺＴ膜、ＰｂＴｉＯ3 、ＬｉＮｂＯ
3 、ＬｉＴａＯ3 、ＰＬＺＴ等の強誘電性や高誘電性を
示す酸化物膜を挙げることができる。この酸化物膜は公
知の方法で、基板上又は絶縁膜や導電層上に形成するこ
とができる。その方法としては、例えば、酸化物や各元
素単独のターゲットを用いたスパッタリング法、反応性
蒸着法、イオンスパッタリング等が挙げられる。酸化物
膜の膜厚は特に限定されるものではないが、１００〜３
００ｎｍ程度が好ましい。The oxide film according to the present invention is an oxide film containing an element having a high vapor pressure, for example, Pb, Li, etc. Specifically, a PZT film, PbTiO 3 , LiNbO
3 , oxide films having ferroelectricity or high dielectricity, such as LiTaO 3 and PLZT. This oxide film can be formed over a substrate or over an insulating film or a conductive layer by a known method. Examples of the method include a sputtering method using a target of an oxide or each element alone, a reactive evaporation method, and ion sputtering. Although the thickness of the oxide film is not particularly limited,
It is preferably about 00 nm.
【００１２】本発明の１つの好ましい形態においては、
酸化物膜を形成したのち、熱処理前に酸化物の表面をダ
イヤモンド状炭素膜で被覆する。ダイヤモンド状炭素膜
とは、非晶質の結晶構造を有しており、硬度、電気抵
抗、熱伝導度等が、結晶ダイヤモンドに近い特性を有す
る膜のことをいう。In one preferred form of the invention,
After forming the oxide film, the surface of the oxide is covered with a diamond-like carbon film before heat treatment. The diamond-like carbon film refers to a film having an amorphous crystal structure and having characteristics such as hardness, electric resistance, and thermal conductivity close to those of crystalline diamond.
【００１３】このようなダイヤモンド状炭素膜は、イオ
ン蒸着法やプラズマＣＶＤ法により形成することができ
る。イオン蒸着法は、イオン源を装備した真空槽内で酸
化物膜表面に炭素イオンを照射することで成膜する方法
であり、この際のイオン源としては特に限定されるもの
ではなく、カウマン型又はバケット型等のガスイオン源
を用いることができる。また、プラズマＣＶＤ法では、
例えば、メタンガス、エタンガス等の炭化水素ガスをプ
ラズマ解離させ、成膜する方法である。しかし、プラズ
マＣＶＤ法では、成膜中に酸化物膜表面が水素イオンに
さらされるために、還元作用により膜中の酸素が失われ
る恐れがあるので、イオン源で生成される炭素イオンを
照射するイオン蒸着法を用いることが好ましい。イオン
源によりダイヤモンド状炭素膜を形成する場合、例え
ば、原料ガスとしてメタン、エチレン等が好ましく、そ
の際の導入量は３〜９ＳＣＣＭ程度、装置内の圧力は３
×１０-5〜１×１０-4Ｔｏｒｒ程度、イオンの加速エネ
ルギーは１５０〜４００ｅＶ程度、イオン電流密度は１
〜１０μＡ／ｃｍ2 程度、基板の温度は３０〜８０℃程
度、イオンの照射時間は３０〜１２０分間程度が好まし
い。また、その際の膜厚は熱処理の条件等により適宜調
節することができるが、１０〜５０ｎｍ程度が好まし
い。Such a diamond-like carbon film can be formed by an ion deposition method or a plasma CVD method. The ion deposition method is a method in which a film is formed by irradiating the surface of an oxide film with carbon ions in a vacuum chamber equipped with an ion source, and the ion source at this time is not particularly limited, and may be a Cowman type. Alternatively, a gas ion source of a bucket type or the like can be used. In the plasma CVD method,
For example, there is a method in which a hydrocarbon gas such as a methane gas and an ethane gas is dissociated by plasma to form a film. However, in the plasma CVD method, since the oxide film surface is exposed to hydrogen ions during the film formation, oxygen in the film may be lost due to a reduction action. Therefore, carbon ions generated by an ion source are irradiated. It is preferable to use an ion deposition method. When a diamond-like carbon film is formed by an ion source, for example, methane, ethylene, or the like is preferable as a raw material gas.
× 10 -5 to 1 × 10 -4 Torr, ion acceleration energy is about 150 to 400 eV, and ion current density is 1
~10μA / cm 2 or so, about the temperature of the substrate is 30 to 80 ° C., the irradiation time of the ions is preferably about 30 to 120 minutes. Further, the film thickness at that time can be appropriately adjusted depending on the conditions of the heat treatment and the like, but is preferably about 10 to 50 nm.
【００１４】そして、酸化物膜上にダイヤモンド状炭素
膜を形成した後、熱処理を行う。熱処理は、酸素雰囲気
下、大気下、アルゴン雰囲気下等で、６００〜７００℃
程度の温度範囲で１〜１０分間、ＲＴＡ法により行うこ
とができる。酸素雰囲気下で熱処理した場合には、ダイ
ヤモンド状炭素膜が、酸素と反応して二酸化炭素となり
消失するので、後工程でダイヤモンド状炭素膜を除去す
ることが不要であるので、特に好ましい。また、その他
の条件等は特に限定されるものではないが、例えば、昇
温速度が１０〜５０℃／秒程度、降温速度が１０〜５０
℃／秒程度が好ましい。After forming a diamond-like carbon film on the oxide film, heat treatment is performed. The heat treatment is performed at 600 to 700 ° C. in an oxygen atmosphere, an air atmosphere, an argon atmosphere, or the like.
It can be performed by the RTA method in a temperature range of about 1 to 10 minutes. The heat treatment in an oxygen atmosphere is particularly preferable because the diamond-like carbon film reacts with oxygen and becomes carbon dioxide and disappears, so that it is not necessary to remove the diamond-like carbon film in a later step. Further, other conditions and the like are not particularly limited. For example, the heating rate is about 10 to 50 ° C./sec, and the cooling rate is about 10 to 50 ° C.
C./sec is preferred.
【００１５】また、本発明の第２の好ましい形態におい
ては、ゾル−ゲル法により被覆膜を形成する場合には、
まず、酸化物膜を上記と同様の方法、例えば、酸化物や
各元素単独のターゲットを用いたスパッタリング法、反
応性蒸着法、イオンスパッタリング等により形成する。
そして、その後、ゾル−ゲル法により被覆膜を形成する
前に、酸化物膜の結晶化等のための熱処理を行う。この
場合の熱処理は、酸素雰囲気下、大気下、アルゴン雰囲
気下等で、６００〜７００℃程度の温度範囲で１〜１０
分間、ＲＴＡ法により行うことができる。また、その他
の条件等は特に限定されるものではないが、例えば、昇
温速度が１０〜５０℃／分程度、降温速度が１０〜５０
℃／分程度が好ましい。このように熱処理することで、
酸化物膜が結晶化する。In a second preferred embodiment of the present invention, when the coating film is formed by a sol-gel method,
First, an oxide film is formed by a method similar to the above, for example, a sputtering method using a target of an oxide or each element alone, a reactive evaporation method, or ion sputtering.
Then, before forming a coating film by a sol-gel method, heat treatment for crystallization of the oxide film or the like is performed. In this case, the heat treatment is performed in an oxygen atmosphere, an air atmosphere, an argon atmosphere, or the like, in a temperature range of about 600 to 700 ° C. for 1 to 10 hours.
The RTA method can be performed for a minute. Further, other conditions and the like are not particularly limited. For example, the heating rate is about 10 to 50 ° C./min, and the cooling rate is 10 to 50 ° C.
C./minute is preferred. By performing such heat treatment,
The oxide film crystallizes.
【００１６】そして、熱処理された酸化物膜上にゾル−
ゲル法により被覆膜を形成する。このゾル−ゲル法に
は、上記で形成した酸化物膜を構成する元素と同一の構
成金属元素の塩又はアルコキシドを用いることが好まし
い。例えば、ＰＺＴ膜の場合には、Ｐｂ、Ｚｒ及びＴｉ
の金属塩又はアルコキシドを用いることができる。具体
的には、Zr（OC4 H 9 ) 4 、Ｔｉ( OC4 H 9 ) 4 、Ｐｂ
（OC2 H 5 ）2 を所望の割合で混合し、水を加えて加水
分解を行い、ゾルを得る。このゾルを、例えばスピンコ
ート法により、上記の酸化物膜上に塗布する。この際の
ゾルの粘度等は塗布に用いるスピナーの回転数等によっ
て適宜調製することができる。また、塗布するゾルの膜
厚は１０〜５０ｎｍ程度が好ましい。このようにして得
られた被覆膜の組成は、被覆膜を構成する元素の種類に
より、特に限定されるものではないが、酸化物の構成元
素のうち、蒸気圧の高い元素の含有量が、ストイキオメ
トリ組成より１０％以上多いことが好ましい。[0016] Then, a sol is formed on the heat-treated oxide film.
A coating film is formed by a gel method. In this sol-gel method, it is preferable to use a salt or alkoxide of the same constituent metal element as the element forming the oxide film formed above. For example, in the case of a PZT film, Pb, Zr and Ti
Can be used. Specifically, Zr (OC 4 H 9 ) 4 , Ti (OC 4 H 9 ) 4 , Pb
(OC 2 H 5 ) 2 is mixed in a desired ratio, and water is added to carry out hydrolysis to obtain a sol. This sol is applied on the oxide film by, for example, spin coating. At this time, the viscosity and the like of the sol can be appropriately adjusted depending on the number of revolutions of a spinner used for coating and the like. The thickness of the sol to be applied is preferably about 10 to 50 nm. The composition of the coating film obtained in this manner is not particularly limited by the type of elements constituting the coating film, but the content of the element having a high vapor pressure among the constituent elements of the oxide. Is preferably at least 10% higher than the stoichiometric composition.
【００１７】上記のようにゾルを塗布したのち、熱処理
を行う。この際の熱処理は酸素雰囲気、大気雰囲気等の
下、４００〜５００℃、好ましくは４３０〜４７０℃で
１０〜３０分間程度行うことが好ましい。上記のように
形成された酸化物結晶膜は種々の半導体装置、例えばＤ
ＲＡＭ、ＦＲＡＭ（強誘電体不揮発性メモリ）等、およ
びＤＲＡＭ、ＭＭＩＣ（Microwave Monolithic IC)等の
キャパシタ等に広く利用することができる。After applying the sol as described above, heat treatment is performed. The heat treatment at this time is preferably performed in an oxygen atmosphere, an air atmosphere, or the like at 400 to 500 ° C., preferably 430 to 470 ° C. for about 10 to 30 minutes. The oxide crystal film formed as described above can be used for various semiconductor devices such as D
It can be widely used for RAM, FRAM (ferroelectric nonvolatile memory), etc., and capacitors such as DRAM, MMIC (Microwave Monolithic IC).
【００１８】[0018]
【作用】本発明の酸化物結晶膜の製造方法によれば、基
板上に、酸化物膜を形成し、該酸化物膜の表面をダイヤ
モンド状炭素膜で被覆した後、熱処理するので、熱処理
の際の酸化物膜表面からの構成元素の蒸発を抑える。例
えば、酸化物膜中に蒸気圧の高い元素が存在している場
合でも、ダイヤモンド状炭素膜が、熱処理中の蒸気圧の
高い構成元素の蒸発を抑えるため、熱処理が終了して酸
化物膜が結晶化した後でも、成膜時のストイキオメトリ
組成が維持されることとなる。According to the method for producing an oxide crystal film of the present invention, an oxide film is formed on a substrate, and the surface of the oxide film is coated with a diamond-like carbon film and then heat-treated. Evaporation of constituent elements from the surface of the oxide film at the time is suppressed. For example, even when an element having a high vapor pressure is present in the oxide film, the diamond-like carbon film suppresses evaporation of the constituent elements having a high vapor pressure during the heat treatment. Even after crystallization, the stoichiometric composition at the time of film formation is maintained.
【００１９】また、基板上に酸化物膜を形成し、熱処理
により該酸化物膜を酸化物結晶膜にした後、該酸化物結
晶膜上に、該膜中の少なくとも１種の構成元素を含有す
る被覆層をゾル−ゲル法により形成し、さらに５００℃
以下の温度で熱処理を行うので、酸化物結晶膜上の被覆
層から、酸化物膜表面から蒸発した構成元素が、酸化物
結晶膜に拡散する。これによって、酸化物結晶膜中の組
成が補償されることとなり、ストイキオメトリ組成が維
持されると同時に、平滑な膜表面が得られることとな
る。Further, an oxide film is formed on a substrate, the oxide film is turned into an oxide crystal film by heat treatment, and at least one of the constituent elements in the film is contained on the oxide crystal film. Coating layer formed by a sol-gel method,
Since heat treatment is performed at the following temperature, constituent elements evaporated from the surface of the oxide film diffuse from the coating layer on the oxide crystal film into the oxide crystal film. As a result, the composition in the oxide crystal film is compensated, and the stoichiometric composition is maintained, and at the same time, a smooth film surface is obtained.
【００２０】[0020]
【実施例】本発明の酸化物結晶膜の製造方法の一実施例
を、図１に基づいて説明する。 実施例１ 図１に示したように、まず、基板として、膜厚約２００
０Å程度の熱酸化膜２が形成されたシリコン基板１を用
いた。そのシリコン基板１上に、Ｐｂ(Zr 0.42Ti0.58)O
3 に１０モル％のＰｂＯを添加した焼結体ターゲットを
用いて、ＲＦスパッタ法により、膜厚約５０００ÅのＰ
ＺＴ膜３を形成した。成膜中、シリコン基板１の加熱は
行わなかったが、プラズマの影響により基板温度は約９
５℃であった。スパッタガスはＡｒ／Ｏ2＝３／１と
し、圧力は５×１０-2Torr、ＲＦパワーは５００Ｗであ
った。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the method for producing an oxide crystal film according to the present invention will be described with reference to FIG. Example 1 As shown in FIG.
A silicon substrate 1 on which a thermal oxide film 2 of about 0 ° was formed was used. On the silicon substrate 1, Pb (Zr 0.42 Ti 0.58 ) O
3 using a sintered target prepared by adding 10 mole% of PbO, by an RF sputtering method, a film thickness of about 5000 Å P
A ZT film 3 was formed. During the film formation, the silicon substrate 1 was not heated.
5 ° C. The sputtering gas was Ar / O 2 = 3/1, the pressure was 5 × 10 −2 Torr, and the RF power was 500 W.
【００２１】得られたＰＺＴ膜３の組成をＸ線マイクロ
アナライザー（ＥＰＭＡ）により分析したところ、Ｚｒ
／Ｔｉ＝0.75、Ｐｂ／(Zr+Ti)＝0.96であった。さら
に、ＰＺＴ膜３の結晶性をＸ線回折により調べたとこ
ろ、非晶質の膜であった。次いで、このＰＺＴ膜３の表
面を、ダイヤモンド状炭素膜４により被覆した。ダイヤ
モンド状炭素膜４の形成方法としては、イオンビーム蒸
着法を用い、以下のように行った。The composition of the obtained PZT film 3 was analyzed by an X-ray microanalyzer (EPMA).
/Ti=0.75 and Pb / (Zr + Ti) = 0.96. Further, when the crystallinity of the PZT film 3 was examined by X-ray diffraction, it was found to be an amorphous film. Next, the surface of the PZT film 3 was covered with a diamond-like carbon film 4. As a method for forming the diamond-like carbon film 4, an ion beam evaporation method was used as follows.
【００２２】真空槽内を１０-7Torr台まで真空排気し、
続いてカウフマン型ガスイオン源に約４sccmのエチレン
（Ｃ4Ｈ4）ガスを導入してイオン化した。その後、約１
０cm離れたＰＺＴ膜３表面に３００ｅＶの加速エネルギ
ーで炭素イオンを照射した。この時の真空槽内の真空度
は３×１０-5Torr、イオン電流は約１ｍＡ、ＰＺＴ膜３
が形成されたシリコン基板１の温度は約５０℃であっ
た。この際の炭素膜はアモルファス構造のダイヤモンド
状炭素膜であることをラマン散乱法により確認した。The inside of the vacuum chamber is evacuated to the order of 10 -7 Torr,
Subsequently, about 4 sccm of ethylene (C 4 H 4 ) gas was introduced into the Kaufman-type gas ion source to ionize. Then, about 1
The surface of the PZT film 3 separated by 0 cm was irradiated with carbon ions at an acceleration energy of 300 eV. At this time, the degree of vacuum in the vacuum chamber is 3 × 10 −5 Torr, the ion current is about 1 mA, and the PZT film 3
Was formed at a temperature of about 50 ° C. It was confirmed by Raman scattering that the carbon film at this time was a diamond-like carbon film having an amorphous structure.
【００２３】次いで、ダイヤモンド状炭素膜４コーティ
ングを施したＰＺＴ膜３を、ＲＴＡ法により酸素ガスフ
ロー中で熱処理を施した。ここで、熱処理温度は６５０
℃、保持時間は３分、昇温速度は２０℃／秒、降温速度
は１０℃／秒とした。また、比較例として、上記と同様
に、シリコン基板上に熱酸化膜及びＰＺＴ膜を順次形成
したシリコン基板に、上記と同様に熱処理を施した。Next, the PZT film 3 coated with the diamond-like carbon film 4 was heat-treated by an RTA method in an oxygen gas flow. Here, the heat treatment temperature is 650.
C., the holding time was 3 minutes, the temperature rising rate was 20 ° C./sec, and the temperature decreasing rate was 10 ° C./sec. Further, as a comparative example, a silicon substrate in which a thermal oxide film and a PZT film were sequentially formed on a silicon substrate was subjected to a heat treatment in the same manner as described above.
【００２４】そして、熱処理後の各ＰＺＴ膜について組
成分析を行った結果、ダイヤモンド状炭素膜４でコーテ
ィングを施したＰＺＴ膜３ではＰｂ／(Zr+Ti)＝0.94で
熱処理前の組成からの変化は殆ど認められなかった。一
方、コーティングなしのＰＺＴ膜ではＰｂ／(Zr+Ti)＝
0.83で明らかにＰｂ組成が減少した。A composition analysis was performed on each of the PZT films after the heat treatment. As a result, in the PZT film 3 coated with the diamond-like carbon film 4, Pb / (Zr + Ti) = 0.94 and the change from the composition before the heat treatment. Was hardly recognized. On the other hand, Pb / (Zr + Ti) =
At 0.83, the Pb composition clearly decreased.
【００２５】このことから、ダイヤモンド状炭素膜４コ
ーティングが熱処理中におけるＰＺＴ膜３からのＰｂの
蒸発を抑制するのに効果のあることが分かった。また、
熱処理後のダイヤモンド状炭素膜４についてオージェ電
子分光法（ＡＥＳ）により分析したところ、ＰＺＴ膜３
表面の炭素層の厚さは熱処理に比べて減少していること
が分かった。これは、酸素雰囲気中での熱処理によりダ
イヤモンド状炭素膜が二酸化炭素となって消失したため
と思われる。From this, it was found that the coating of the diamond-like carbon film 4 was effective in suppressing the evaporation of Pb from the PZT film 3 during the heat treatment. Also,
The diamond-like carbon film 4 after the heat treatment was analyzed by Auger electron spectroscopy (AES).
It was found that the thickness of the surface carbon layer was reduced as compared with the heat treatment. This is probably because the diamond-like carbon film was converted to carbon dioxide and disappeared by the heat treatment in the oxygen atmosphere.
【００２６】従って、ダイヤモンド状炭素膜４のコーテ
ィング膜厚を適当な厚さに選択することによって、熱処
理中のＰｂの蒸発を抑制すると同時に、ダイヤモンド状
炭素膜４の除去が同時に実現できるものである。なお、
熱処理後のＰＺＴ膜３のＸ線回折パターンは、ペロブス
カイト構造の単一相を示していた。Therefore, by selecting an appropriate coating thickness of the diamond-like carbon film 4, the evaporation of Pb during the heat treatment can be suppressed, and the removal of the diamond-like carbon film 4 can be realized at the same time. . In addition,
The X-ray diffraction pattern of the PZT film 3 after the heat treatment showed a single phase having a perovskite structure.
【００２７】実施例２ まず、基板として、膜厚約２０００Å程度の熱酸化膜２
が形成されたシリコン基板を用いた。そのシリコン基板
上に、Ｐｂ(Zr 0.42Ti0.58)O3 に１０モル％のＰｂＯを
添加した焼結体ターゲットを用いて、ＲＦスパッタ法に
より、膜厚約２００ｎｍのＰＺＴ膜を形成した。成膜
中、シリコン基板の加熱は行わなかったが、プラズマの
影響により基板温度は約９５℃であった。スパッタガス
はＡｒ／Ｏ 2＝３／１とし、圧力は５×１０-2Torr、Ｒ
Ｆパワーは５００Ｗであった。Example 2 First, a thermal oxide film 2 having a thickness of about 2000
Was used. The silicon substrate
Above, Pb (Zr0.42Ti0.58) OThreeWith 10 mol% PbO
Using the added sintered body target, RF sputtering
Thus, a PZT film having a thickness of about 200 nm was formed. Film formation
During the heating, the silicon substrate was not heated,
Due to the influence, the substrate temperature was about 95 ° C. Sputter gas
Is Ar / O Two= 3/1 and the pressure is 5 × 10-2Torr, R
The F power was 500W.
【００２８】得られたＰＺＴ膜の組成をＥＰＭＡとＡＥ
Ｓとにより分析したところ、Ｚｒ／Ｔｉ＝0.75、Ｐｂ／
(Zr+Ti)＝1.06であり、膜厚方向に均一な組成であるこ
とが確認された。さらに、ＰＺＴ膜の結晶性をＸ線回折
により調べたところ、非晶質の膜であった。次いで、こ
のＰＺＴ膜を結晶化するため、ＲＴＡ法により酸素ガス
フロー中で熱処理を施した。ここで、熱処理温度は６５
０℃、保持時間は１５秒間、昇温速度は２０℃／秒、降
温速度は１０℃／秒とした。The composition of the obtained PZT film was determined by EPMA and AE.
Analysis by S and Zr / Ti = 0.75, Pb /
(Zr + Ti) = 1.06, and it was confirmed that the composition was uniform in the film thickness direction. Further, when the crystallinity of the PZT film was examined by X-ray diffraction, it was found to be an amorphous film. Next, in order to crystallize the PZT film, a heat treatment was performed in an oxygen gas flow by an RTA method. Here, the heat treatment temperature is 65
At 0 ° C., the holding time was 15 seconds, the temperature rising rate was 20 ° C./second, and the temperature decreasing rate was 10 ° C./second.
【００２９】熱処理後のＰＺＴ膜についてＸ線回折パタ
ーンを測定した結果、ペロブスカイト構造の無配向膜で
あることが確認された。また、組成分析を行った結果、
Ｐｂ／(Zr+Ti)＝0.83であり、明らかにＰｂ組成の減少
が確認された。さらに、ＡＥＳ分析からは、Zr/Ti 比は
熱処理前と変わらず膜厚方向で一定であったが、Ｐｂ量
は膜表面に向かって徐々に減少していた。また、膜表面
の形状を走査型電子顕微鏡（ＳＥＭ）と原子間力顕微鏡
（ＡＦＭ）とにより観察したところ、直径１００ｎｍ程
度の粒子により覆われており、その平均表面粗さはＲａ
＝１０．６ｎｍであった。As a result of measuring the X-ray diffraction pattern of the heat-treated PZT film, it was confirmed that the PZT film was a non-oriented film having a perovskite structure. Also, as a result of composition analysis,
Pb / (Zr + Ti) = 0.83, and a clear decrease in the Pb composition was confirmed. Further, according to the AES analysis, the Zr / Ti ratio was constant in the film thickness direction as before, but the Pb amount gradually decreased toward the film surface. When the shape of the film surface was observed with a scanning electron microscope (SEM) and an atomic force microscope (AFM), the film was covered with particles having a diameter of about 100 nm, and the average surface roughness was Ra.
= 10.6 nm.
【００３０】次に、上記の熱処理後のＰＺＴ膜上に、ゾ
ル−ゲル法によるＰＺＴ膜の形成を行った。原料ゾルの
合成には金属アルコキシドを用いた。ゾルの合成方法は
Zr(OC4 H 9 ) 4 及びＴｉ( OC4 H 9 ) 4 のエタノール
（Ｃ2 Ｈ5 ＯＨ）溶液のそれぞれに、等モルのCH3 COCH
2 COCH3 を加えて室温で攪拌反応させたのち、これらの
混合溶液にＰｂ（ＯＣ2 Ｈ5 ）2 のエタノール溶液を添
加した。このとき、組成比がＰｂ：Ｚｒ：Ｔｉ＝１．
３：０．５：０．５となるように各成分溶液の割合を調
製した。こうして得られた溶液に水を加えて加水分解
し、上記熱処理後のＰＺＴ膜上にスピンコートし、乾燥
した。ここで、１回のコーティングによる膜厚は約２０
ｎｍであった。また、基板ＰＺＴ表面の凹凸を平滑に覆
うことができるように、ゾルの粘度及びスピーナの回転
速度を調整した。次にＰＺＴ膜中の有機物成分を分解、
燃焼させるために、４００℃で１時間の仮焼成を行っ
た。この温度ではＰＺＴの結晶化は起こらないため、上
部ゾル−ゲル法ＰＺＴ膜は表面平滑な非晶質である。Ａ
ＥＳ分析の結果、上部ゾル−ゲル法ＰＺＴ膜と下部スパ
ッタ膜の境界でＰｂ濃度に段差のあることが確認でき
た。これはゾル組成と下部ＰＺＴ膜のＰｂ量の違いに対
応するものである。Next, a PZT film was formed on the heat-treated PZT film by the sol-gel method. A metal alkoxide was used for the synthesis of the raw material sol. How to synthesize sol
An equimolar amount of CH 3 COCH was added to each of an ethanol (C 2 H 5 OH) solution of Zr (OC 4 H 9 ) 4 and Ti (OC 4 H 9 ) 4.
After adding 2 COCH 3 and reacting with stirring at room temperature, an ethanol solution of Pb (OC 2 H 5 ) 2 was added to these mixed solutions. At this time, when the composition ratio is Pb: Zr: Ti = 1.
The ratio of each component solution was adjusted so as to be 3: 0.5: 0.5. The solution thus obtained was hydrolyzed by adding water, spin-coated on the heat-treated PZT film, and dried. Here, the film thickness by one coating is about 20.
nm. Further, the viscosity of the sol and the rotation speed of the spinner were adjusted so that the unevenness on the surface of the substrate PZT could be covered smoothly. Next, the organic components in the PZT film are decomposed,
In order to burn, calcination was performed at 400 ° C. for 1 hour. Since PZT does not crystallize at this temperature, the upper sol-gel method PZT film is amorphous with a smooth surface. A
As a result of ES analysis, it was confirmed that there was a step in the Pb concentration at the boundary between the upper sol-gel method PZT film and the lower sputtered film. This corresponds to the difference between the sol composition and the amount of Pb in the lower PZT film.
【００３１】そして、この試料を４３０℃、４５０℃及
び４７０℃の３種類の温度でそれぞれ３０分間の熱処理
を行い、ＡＥＳによる組成分析とＡＦＭによる表面形状
観察とを行った。膜厚方向の組成分析では、熱処理温度
が高くなるにつれて、上部ゾル−ゲル法ＰＺＴ膜中のＰ
ｂが表面領域で蒸発、減少するのと同時に、下部スパッ
タＰＺＴ膜側への拡散が認められた。すなわち、上部ゾ
ル−ゲル法ＰＺＴ膜は下部スパッタ膜へのＰｂ供給源と
なることがわかった。このことは、結晶化熱処理時に失
われた下部スパッタＰＺＴ膜のＰｂ量を補償して、スト
イキオメトリ組成に近づける効果を持つ。The sample was heat-treated at 430 ° C., 450 ° C. and 470 ° C. for 30 minutes each, and the composition analysis by AES and the surface shape observation by AFM were performed. In the composition analysis in the film thickness direction, as the heat treatment temperature increases, the P in the upper sol-gel PZT film becomes higher.
At the same time as b evaporated and decreased in the surface region, diffusion to the lower sputtered PZT film side was observed. That is, it was found that the upper sol-gel PZT film became a Pb supply source for the lower sputtered film. This has the effect of compensating for the amount of Pb in the lower sputtered PZT film lost during the crystallization heat treatment and approaching the stoichiometric composition.
【００３２】表面形状については、熱処理温度によらず
表面粗さには変化はなくＲａ＝２．３ｎｍであった。こ
の結果は、これらの熱処理温度がＰＺＴの結晶化には十
分でないためと推測される。以上の結果から、上部ゾル
−ゲルＰＺＴ膜は下部スパッタＰＺＴ膜と共に、次の３
つの効果があることが結論される。 １．結晶化熱処理後のＰＺＴ表面凹凸を被覆し、表面平
滑化を実現する。 ２．結晶化熱処理時に膜中から失われたＰｂ成分を供
給、補償する。 ３．上部ゾル−ゲル法ＰＺＴ膜自体は非晶質であり、Ｐ
ＺＴ膜全体のリーク電流を抑制する。Regarding the surface shape, there was no change in the surface roughness regardless of the heat treatment temperature, and Ra was 2.3 nm. This result is presumed to be because these heat treatment temperatures are not sufficient for crystallization of PZT. From the above results, the upper sol-gel PZT film was formed together with the lower sputtered PZT film in the following 3
It is concluded that there are two effects. 1. Covers the PZT surface irregularities after the crystallization heat treatment, and realizes surface smoothing. 2. The Pb component lost from the film during the crystallization heat treatment is supplied and compensated. 3. The upper sol-gel PZT film itself is amorphous,
Suppresses leakage current in the entire ZT film.
【００３３】これらの効果を利用することで、膜厚の低
減に伴うリーク電流の増加の原因となる表面凹凸、ピン
ホールの発生を抑制でき、かつ上部非晶質層が下部結晶
層に比べて十分に薄いために強誘電特性をも損なわない
高品質ＰＺＴ薄膜を得ることが可能となる。By utilizing these effects, it is possible to suppress the occurrence of surface irregularities and pinholes which cause an increase in leakage current due to a decrease in film thickness, and that the upper amorphous layer is smaller than the lower crystalline layer. Since it is sufficiently thin, it is possible to obtain a high quality PZT thin film that does not impair ferroelectric properties.
【００３４】[0034]
【発明の効果】本発明の酸化物結晶膜の製造方法によれ
ば、基板上に、酸化物膜を形成し、該酸化物膜の表面を
ダイヤモンド状炭素膜で被覆した後、熱処理するので、
酸化物膜中に蒸気圧の高い元素が存在している場合で
も、ダイヤモンド状炭素膜が、熱処理中の蒸気圧の高い
構成元素の蒸発を抑えることとなる。つまり、蒸気圧の
大きく異なる成分からなる酸化物膜において、熱処理が
終了して酸化物膜が結晶化した後でも、その酸化物膜の
成膜時の組成変化の発生を防止し、ストイキオメトリ組
成を維持することができ、高品質な酸化物結晶膜を再現
性良く得ることができる。According to the method for producing an oxide crystal film of the present invention, an oxide film is formed on a substrate, and the surface of the oxide film is coated with a diamond-like carbon film and then heat-treated.
Even when an element having a high vapor pressure is present in the oxide film, the diamond-like carbon film suppresses evaporation of constituent elements having a high vapor pressure during the heat treatment. In other words, in an oxide film composed of components having greatly different vapor pressures, even after the heat treatment is completed and the oxide film is crystallized, it is possible to prevent a change in composition during the formation of the oxide film, and to achieve stoichiometry. The composition can be maintained, and a high-quality oxide crystal film can be obtained with good reproducibility.
【００３５】また、基板上に酸化物膜を形成し、熱処理
により該酸化物膜を酸化物結晶膜にした後、該酸化物結
晶膜上に、該膜中の少なくとも１種の構成元素を含有す
る被覆層をゾル−ゲル法により形成し、さらに５００℃
以下の温度で熱処理を行うので、酸化物結晶膜上の被覆
層から、酸化物膜表面から蒸発した構成元素を、酸化物
結晶膜に拡散することができる。これによって、酸化物
結晶膜中の組成が補償されることとなり、ストイキオメ
トリ組成を維持することができると同時に、平滑な膜表
面を得ることができる。An oxide film is formed on a substrate, the oxide film is turned into an oxide crystal film by heat treatment, and at least one of the constituent elements in the film is contained on the oxide crystal film. Coating layer formed by a sol-gel method,
Since heat treatment is performed at the following temperature, constituent elements evaporated from the surface of the oxide film can be diffused from the coating layer on the oxide crystal film to the oxide crystal film. As a result, the composition in the oxide crystal film is compensated, so that the stoichiometric composition can be maintained and a smooth film surface can be obtained.
【００３６】従って、上記酸化物膜のような強誘電性及
び高誘電性を示す材料を用いた不揮発性メモリ等の各種
デバイスへの応用が可能となる。Therefore, the present invention can be applied to various devices such as a nonvolatile memory using a material having ferroelectricity and high dielectric property such as the above oxide film.
【図１】本発明に係る膜構造を示す概略断面図である。FIG. 1 is a schematic sectional view showing a film structure according to the present invention.
１ シリコン基板 ２ シリコン熱酸化膜 ３ ＰＺＴ膜 ４ ダイヤモンド状炭素膜 Reference Signs List 1 silicon substrate 2 silicon thermal oxide film 3 PZT film 4 diamond-like carbon film
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) C30B 1/00 - 35/00 C23C 16/56 H01L 21/20 H01L 41/22 ──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. 7 , DB name) C30B 1/00-35/00 C23C 16/56 H01L 21/20 H01L 41/22
Claims (7)
膜の表面をダイヤモンド状炭素膜で被覆した後、熱処理
することを特徴とする酸化物結晶膜の製造方法。1. A method for manufacturing an oxide crystal film, comprising: forming an oxide film on a substrate, covering the surface of the oxide film with a diamond-like carbon film, and performing a heat treatment.
る請求項１記載の酸化物結晶膜の製造方法。2. The method according to claim 1, wherein the oxide film is a ferroelectric lead-containing oxide film.
ダイヤモンド状炭素膜が１０〜５０ｎｍの膜厚で形成す
る請求項１記載の酸化物結晶膜の製造方法。3. An oxide film having a thickness of 100 to 300 nm,
The method for producing an oxide crystal film according to claim 1, wherein the diamond-like carbon film is formed with a thickness of 10 to 50 nm.
１〜１０分間行う請求項１記載の酸化物結晶膜の製造方
法。4. The method for producing an oxide crystal film according to claim 1, wherein the heat treatment is performed in a temperature range of 600 to 700 ° C. for 1 to 10 minutes.
℃の温度範囲で１〜１０分間行う請求項１記載の酸化物
結晶膜の製造方法。5. The heat treatment is performed in an oxygen atmosphere at 600 to 700.
The method for producing an oxide crystal film according to claim 1, wherein the method is performed at a temperature of 1 ° C. for 1 to 10 minutes.
より該酸化物膜を酸化物結晶膜にした後、該酸化物結晶
膜上に、該膜中の少なくとも１種の構成元素を含有する
被覆層をゾル−ゲル法により形成し、さらに５００℃以
下の温度で熱処理を行うことを特徴とする酸化物結晶膜
の製造方法。6. An oxide film is formed on a substrate, and the oxide film is turned into an oxide crystal film by heat treatment. Then, at least one kind of constituent element in the film is formed on the oxide crystal film. A method for producing an oxide crystal film, comprising forming a coating layer to be contained by a sol-gel method, and further performing a heat treatment at a temperature of 500 ° C. or less.
り、かつ被覆層に含有される元素が鉛である請求項６記
載の酸化物結晶膜の製造方法。7. The method for producing an oxide crystal film according to claim 6, wherein the oxide film is a ferroelectric lead-containing oxide film, and the element contained in the coating layer is lead.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8966793A JP3098134B2 (en) | 1993-04-16 | 1993-04-16 | Method for manufacturing oxide crystal film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8966793A JP3098134B2 (en) | 1993-04-16 | 1993-04-16 | Method for manufacturing oxide crystal film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06305897A JPH06305897A (en) | 1994-11-01 |
| JP3098134B2 true JP3098134B2 (en) | 2000-10-16 |
Family
ID=13977104
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|---|---|---|---|
| JP8966793A Expired - Fee Related JP3098134B2 (en) | 1993-04-16 | 1993-04-16 | Method for manufacturing oxide crystal film |
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| Country | Link |
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| JP3113141B2 (en) * | 1993-12-28 | 2000-11-27 | シャープ株式会社 | Ferroelectric crystal thin film coated substrate, method of manufacturing the same, and ferroelectric thin film device using ferroelectric crystal thin film coated substrate |
| JP5314963B2 (en) * | 2008-08-12 | 2013-10-16 | 富士フイルム株式会社 | LAMINATE, PIEZOELECTRIC ELEMENT, AND LIQUID DISCHARGE DEVICE |
| JP5371329B2 (en) * | 2008-08-29 | 2013-12-18 | 富士フイルム株式会社 | Piezoelectric element and liquid ejection device |
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1993
- 1993-04-16 JP JP8966793A patent/JP3098134B2/en not_active Expired - Fee Related
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|---|---|
| JPH06305897A (en) | 1994-11-01 |
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