JP5656216B2 - Method for manufacturing silicon carbide semiconductor element and method for manufacturing electronic device - Google Patents

Method for manufacturing silicon carbide semiconductor element and method for manufacturing electronic device Download PDF

Info

Publication number
JP5656216B2
JP5656216B2 JP2010217756A JP2010217756A JP5656216B2 JP 5656216 B2 JP5656216 B2 JP 5656216B2 JP 2010217756 A JP2010217756 A JP 2010217756A JP 2010217756 A JP2010217756 A JP 2010217756A JP 5656216 B2 JP5656216 B2 JP 5656216B2
Authority
JP
Japan
Prior art keywords
silicon carbide
manufacturing
nitrogen
semiconductor element
carbide semiconductor
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.)
Active
Application number
JP2010217756A
Other languages
Japanese (ja)
Other versions
JP2012074513A (en
Inventor
長野　正裕
正裕 長野
ローゼン ジョン
ローゼン ジョン
秀一 土田
秀一 土田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Central Research Institute of Electric Power Industry
Original Assignee
Central Research Institute of Electric Power Industry
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Central Research Institute of Electric Power Industry filed Critical Central Research Institute of Electric Power Industry
Priority to JP2010217756A priority Critical patent/JP5656216B2/en
Publication of JP2012074513A publication Critical patent/JP2012074513A/en
Application granted granted Critical
Publication of JP5656216B2 publication Critical patent/JP5656216B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Formation Of Insulating Films (AREA)

Description

本発明は、炭化珪素と酸化膜との界面準位密度を低減することができる炭化珪素半導体素子の製造方法及び電子デバイスの製造方法に関する。 The present invention relates to a method for manufacturing a silicon carbide semiconductor element and a method for manufacturing an electronic device that can reduce the interface state density between silicon carbide and an oxide film.

炭化珪素（ＳｉＣ）は、シリコンと比べてバンドギャップが約３倍、飽和ドリフト速度が約２倍、絶縁破壊電界強度が約１０倍と優れた物性値を有し、大きな熱伝導率を有する半導体であることから、現在用いられているシリコン単結晶半導体の性能を大きく凌駕する次世代の高電圧・低損失半導体素子を実現する材料として期待されている。   Silicon carbide (SiC) is a semiconductor that has excellent physical properties such as a band gap of about 3 times, a saturation drift velocity of about 2 times, and a breakdown electric field strength of about 10 times that of silicon, and a large thermal conductivity. Therefore, it is expected as a material for realizing a next-generation high-voltage / low-loss semiconductor device that greatly surpasses the performance of currently used silicon single crystal semiconductors.

炭化珪素は、シリコンと同様の手法により絶縁膜を形成することが可能であるため、炭化珪素をベースに製造された電子デバイス、例えばＭＯＳＦＥＴの研究が盛んに行われている。しかし、炭化珪素ＭＯＳＦＥＴのオン抵抗は物性値から予測される性能には及ばない。この原因として、炭化珪素ＭＯＳＦＥＴのチャネル移動度がシリコンＭＯＳＦＥＴのチャネル移動度に比べて小さいことが挙げられている。これは、炭化珪素と絶縁膜の界面における界面準位密度が高いことが原因と考えられている。   Since silicon carbide can form an insulating film by a method similar to that of silicon, research on electronic devices manufactured based on silicon carbide, such as MOSFETs, has been actively conducted. However, the on-resistance of the silicon carbide MOSFET does not reach the performance predicted from the physical property values. This is because the channel mobility of the silicon carbide MOSFET is smaller than the channel mobility of the silicon MOSFET. This is considered to be caused by a high interface state density at the interface between silicon carbide and the insulating film.

界面準位密度を低減する方法としては、炭化珪素上に絶縁膜を形成し、加熱された窒素化合物雰囲気中に曝露することにより、絶縁膜の内部に窒素を拡散させる窒化処理が開示されている（例えば、特許文献１、非特許文献１〜４参照）。この窒化処理により界面準位密度がある程度低減される。   As a method for reducing the interface state density, a nitriding treatment is disclosed in which an insulating film is formed on silicon carbide and exposed to a heated nitrogen compound atmosphere to diffuse nitrogen into the insulating film. (For example, refer to Patent Document 1 and Non-Patent Documents 1 to 4). This nitriding treatment reduces the interface state density to some extent.

また、６Ｈ−ＳｉＣ（０００１）面を有する基板に対して、チャンバ内において水素でエッチングを行い、続けて窒素雰囲気の下でアニーリングを行い、その後、チャンバから出して大気中に放置し、自然酸化させる技術が開示されている（例えば、非特許文献５参照）。そのような工程を経た基板は、表面のダングリングボンドが窒素等で終端され、ＳｉＯＮ膜が形成される。   In addition, a substrate having a 6H—SiC (0001) surface is etched with hydrogen in the chamber, followed by annealing in a nitrogen atmosphere, and then removed from the chamber and left in the atmosphere to be naturally oxidized. The technique to make is disclosed (for example, refer nonpatent literature 5). In the substrate that has undergone such a process, dangling bonds on the surface are terminated with nitrogen or the like, and a SiON film is formed.

特開２００６−２１０８１８号公報JP 2006-210818 A

"Increase in oxide hole trap density associated with nitrogen incorporation at the SiO2/SiC interface", John Rozen, Sarit Dhar, S. K. Dixit, V. V. Afanas’ev, F. O. Roberts, H. L. Dang, Sanwu Wang, S. T. Pantelides, J. R. Williams, and L. C. Feldman, J. Appl. Phys. 104, 124513(2008)."Increase in oxide hole trap density associated with nitrogen incorporation at the SiO2 / SiC interface", John Rozen, Sarit Dhar, SK Dixit, VV Afanas'ev, FO Roberts, HL Dang, Sanwu Wang, ST Pantelides, JR Williams, and LC Feldman, J. Appl. Phys. 104, 124513 (2008). "Impact of Nitridation on Negative and Positive Charge Buildup in SiC Gate Oxides ", John Rozen, Sarit Dhar, Sanwu Wang, V. V. Afanas’ev, S. T. Pantelides, J. R. Williams, and L. C. Feldman, Materials Science Forum Vols. 600-603 (2009) pp 803-806."Impact of Nitridation on Negative and Positive Charge Buildup in SiC Gate Oxides", John Rozen, Sarit Dhar, Sanwu Wang, VV Afanas'ev, ST Pantelides, JR Williams, and LC Feldman, Materials Science Forum Vols. 600-603 (2009 ) pp 803-806. "Density of interface states, electron traps, and hole traps as a function of the nitrogen density in SiO2 on SiC ", John Rozen, Sarit Dhar, M. E. Zvanut, J. R. Williams, and L. C. Feldman, J. Appl. Phys. 105, 124506(2009)."Density of interface states, electron traps, and hole traps as a function of the nitrogen density in SiO2 on SiC", John Rozen, Sarit Dhar, ME Zvanut, JR Williams, and LC Feldman, J. Appl. Phys. 105, 124506 (2009). "Suppression of interface state generation upon electron injection in nitrided oxides grown on 4H-SiC ", John Rozen, Sarit Dhar, S. T. Pantelides, and L. C. Feldman, J. Appl. Phys. 91, 153503 (2007)."Suppression of interface state generation upon electron injection in nitrided oxides grown on 4H-SiC", John Rozen, Sarit Dhar, S. T. Pantelides, and L. C. Feldman, J. Appl. Phys. 91, 153503 (2007). "Epitaxial Silicon Oxynitride Layer on 6H-SiC(0001) Surface ", Tetsuroh Shirakawa, Kenjiro Hayashi, Seigi Mizuno, Satoru Tanaka, Kan Nakatsuji, Fumio Komori, and Hiroshi Tochihara, Phys. Rev. Lett. 98, 136105 (2007)."Epitaxial Silicon Oxynitride Layer on 6H-SiC (0001) Surface", Tetsuroh Shirakawa, Kenjiro Hayashi, Seigi Mizuno, Satoru Tanaka, Kan Nakatsuji, Fumio Komori, and Hiroshi Tochihara, Phys. Rev. Lett. 98, 136105 (2007).

しかしながら、上述の特許文献１や非特許文献１〜４に開示された技術では、炭化珪素と酸化膜との間に窒素が十分拡散せず、チャネル移動度などが向上した高性能な電子デバイスを得るためには、界面準位密度のさらなる低減が求められている。また、非特許文献５に開示された技術では、ＳｉＯＮの膜厚は、電子デバイスの酸化膜としては十分な厚さではない。 However, in the techniques disclosed in Patent Document 1 and Non-Patent Documents 1 to 4 described above, a high-performance electronic device in which nitrogen is not sufficiently diffused between silicon carbide and the oxide film and channel mobility is improved. In order to obtain this, further reduction of the interface state density is required. In the technique disclosed in Non-Patent Document 5, the film thickness of SiON is not sufficient as an oxide film of an electronic device.

本発明は、このような事情に鑑み、炭化珪素とその上に形成される酸化膜との界面の品質及び当該酸化膜の品質を改善して界面準位密度を低減することができる炭化珪素半導体素子の製造方法及び電子デバイスの製造方法を提供することを目的とする。 In view of such circumstances, the present invention improves the quality of the interface between silicon carbide and the oxide film formed thereon and the quality of the oxide film, and can reduce the interface state density. An object of the present invention is to provide an element manufacturing method and an electronic device manufacturing method.

上記課題を解決する本発明の第１の態様は、水素を含むクリーニングガスを励起させてプラズマを生成し、プラズマ中の水素により炭化珪素の主表面のダングリングボンドを終端させ、窒素含有ガスを励起させてプラズマを生成し、酸化膜を形成せずにプラズマ中の窒素により前記主表面のダングリングボンドを終端した水素を窒素で置換した後、前記主表面上に酸化膜を形成することを特徴とする炭化珪素半導体素子の製造方法にある。 A first aspect of the present invention that solves the above problems is to generate a plasma by exciting a cleaning gas containing hydrogen, terminate dangling bonds on the main surface of silicon carbide with hydrogen in the plasma, and generate a nitrogen-containing gas. thereby excited to produce plasma after the hydrogen terminating the dangling bonds of the main surface by the nitrogen in the plasma without forming an oxide film was replaced with nitrogen, to form an oxide film on said main surface A method of manufacturing a silicon carbide semiconductor device characterized by the above.

かかる第１の態様では、炭化珪素の主表面に存在していたダングリングボンドが窒素で終端され、炭化珪素の主表面と酸化膜との界面に窒素が存在する炭化珪素半導体素子が作製される。 In the first aspect, a dangling bond present on the main surface of silicon carbide is terminated with nitrogen, and a silicon carbide semiconductor element in which nitrogen is present at the interface between the main surface of silicon carbide and the oxide film is produced. .

このように作製された炭化珪素半導体素子は、ダングリングボンドが窒素で終端されたことにより、界面には欠陥が無く、リーク電流の発生を抑えることができる。また、界面に存在する窒素により界面準位密度が低減され、高品質な界面及び酸化膜が得られる。さらに、酸化膜はデバイスの作製に適した厚さの膜厚とすることができる。 In the silicon carbide semiconductor device manufactured in this manner, dangling bonds are terminated with nitrogen, so that there is no defect at the interface and generation of leakage current can be suppressed. In addition, the interface state density is reduced by nitrogen existing at the interface, and a high-quality interface and oxide film can be obtained. Further, the oxide film can have a thickness suitable for device fabrication.

本発明の第２の態様は、第１の態様に記載する炭化珪素半導体素子の製造方法において、クリーニングガスで表面処理し、窒素含有ガスで表面処理し、主表面上に酸化膜を形成する工程を、同一のチャンバ内で連続的に行うことを特徴とする炭化珪素半導体素子の製造方法にある。 According to a second aspect of the present invention, in the method for manufacturing a silicon carbide semiconductor element according to the first aspect, a surface treatment is performed with a cleaning gas, a surface treatment is performed with a nitrogen-containing gas, and an oxide film is formed on the main surface. In a method for manufacturing a silicon carbide semiconductor device, the method is performed continuously in the same chamber.

かかる第２の態様では、炭化珪素半導体素子を作製するまでの工程を合理的に行うことができる。   In the second aspect, the steps until the silicon carbide semiconductor element is manufactured can be rationally performed.

本発明の第３の態様は、第１の態様に記載する炭化珪素半導体素子の製造方法において、主表面上に酸化膜を形成する工程は、クリーニングガス及び窒素含有ガスの表面処理とは別のチャンバで行うことを特徴とする炭化珪素半導体素子の製造方法にある。 According to a third aspect of the present invention, in the method for manufacturing a silicon carbide semiconductor element according to the first aspect, the step of forming the oxide film on the main surface is different from the surface treatment of the cleaning gas and the nitrogen-containing gas. The present invention resides in a method for manufacturing a silicon carbide semiconductor device, which is performed in a chamber.

かかる第３の態様では、酸化膜を作製する工程において、その前の表面処理で用いたガスの影響を極力避けたい場合に有効である。 This third aspect is effective when it is desired to avoid the influence of the gas used in the previous surface treatment as much as possible in the step of forming the oxide film.

本発明の第４の態様は、第１〜第３の何れか一つの態様に記載する炭化珪素半導体素子の製造方法において、前記酸化膜の厚さを５ｎｍ以上とすることを特徴とする炭化珪素半導体素子の製造方法にある。 According to a fourth aspect of the present invention, in the method for manufacturing a silicon carbide semiconductor element according to any one of the first to third aspects, the thickness of the oxide film is 5 nm or more. It exists in the manufacturing method of a semiconductor element.

かかる第４の態様では、電子デバイスを形成するのに適した膜厚の酸化膜を作製することができる。 In the fourth aspect, an oxide film having a thickness suitable for forming an electronic device can be produced.

本発明の第５の態様は、炭化珪素上に形成された酸化膜を含む電子デバイスの製造方法であって、第１〜第４の何れか一つの態様に記載された製造方法によって前記酸化膜を形成することを特徴とする電子デバイスの製造方法にある。 A fifth aspect of the present invention is a method of manufacturing an electronic device including an oxide film formed on the silicon carbide, the oxide layer by the manufacturing method described in the first to fourth any one of embodiments The method of manufacturing an electronic device is characterized by comprising:

かかる第５の態様では、界面準位密度が低減した炭化珪素半導体素子から、炭化珪素の優れた物性を生かした電子デバイスを作製することができる。   In the fifth aspect, an electronic device utilizing the excellent physical properties of silicon carbide can be produced from a silicon carbide semiconductor element having a reduced interface state density.

本発明によれば、炭化珪素とその上に形成される絶縁膜との界面の品質及び当該絶縁膜の品質を改善して界面準位密度を低減することができる炭化珪素半導体素子の製造方法及び電子デバイスの製造方法が提供される。   According to the present invention, a method for manufacturing a silicon carbide semiconductor element capable of reducing the interface state density by improving the quality of an interface between silicon carbide and an insulating film formed thereon and the quality of the insulating film, and A method for manufacturing an electronic device is provided.

炭化珪素基板上に絶縁膜を作製し、その上に電子デバイスを形成する工程を示すフロー図である。It is a flowchart which shows the process of producing an insulating film on a silicon carbide substrate and forming an electronic device on it. 炭化珪素基板上に絶縁膜を作製し、その上に電子デバイスを形成する工程を示すフロー図である。It is a flowchart which shows the process of producing an insulating film on a silicon carbide substrate and forming an electronic device on it. 本実施形態に係る製造方法により得られた炭化珪素半導体素子と、炭化珪素基板上に、水素終端処理及び窒素終端処理を行わずに絶縁膜を作製することにより得られた炭化珪素半導体素子の界面欠陥密度を示すグラフである。An interface between a silicon carbide semiconductor element obtained by the manufacturing method according to the present embodiment and a silicon carbide semiconductor element obtained by producing an insulating film on a silicon carbide substrate without performing hydrogen termination treatment and nitrogen termination treatment. It is a graph which shows a defect density.

以下、本発明の実施形態に係る炭化珪素半導体素子の製造方法を図面に基づいて詳細に説明する。図１及び図２は、炭化珪素基板上に絶縁膜を作製し、その上に電子デバイスを形成する工程を示すフロー図である。   Hereinafter, a method for manufacturing a silicon carbide semiconductor device according to an embodiment of the present invention will be described in detail with reference to the drawings. 1 and 2 are flowcharts showing a process of forming an insulating film on a silicon carbide substrate and forming an electronic device thereon.

［炭化珪素基板］
図１（ａ）に示すように、チャンバ１０内に炭化珪素基板１を収納する。炭化珪素基板１は、炭化珪素を含む層を有する基板をいう。本実施形態では、主表面が（０００１）面に略平行である４Ｈ−ＳｉＣからなる半導体基板の一方面側に、炭化珪素をエピタキシャル成長させたものを炭化珪素基板１とした。なお、４Ｈ−ＳｉＣの主表面は、（１１−２０）面、（１−１００）面、（０３−３８）面に略平行な面であってもよい。また、炭化珪素基板１としては、他にも、炭化珪素のみからなる基板でもよいし、炭化珪素以外の基板上に炭化珪素をエピタキシャル成長させたものでもよい。なお、本実施形態では、板状の炭化珪素を炭化珪素基板１としたが、これに限らず、本発明は任意の形状の炭化珪素に適用することができる。 [Silicon carbide substrate]
As shown in FIG. 1A, silicon carbide substrate 1 is housed in chamber 10. Silicon carbide substrate 1 refers to a substrate having a layer containing silicon carbide. In the present embodiment, silicon carbide substrate 1 is obtained by epitaxially growing silicon carbide on one surface side of a semiconductor substrate made of 4H—SiC whose main surface is substantially parallel to the (0001) plane. The main surface of 4H—SiC may be a plane substantially parallel to the (11-20) plane, the (1-100) plane, and the (03-38) plane. In addition, silicon carbide substrate 1 may be a substrate made of only silicon carbide, or may be silicon carbide epitaxially grown on a substrate other than silicon carbide. In the present embodiment, the silicon carbide substrate 1 is a plate-like silicon carbide. However, the present invention is not limited to this, and the present invention can be applied to any shape of silicon carbide.

炭化珪素基板１の炭化珪素の結晶多形（ポリタイプ）は、任意の種類を用いることができる。ポリタイプが比較的安定であり、大面積の基板を作製可能であるという観点から、４Ｈ−ＳｉＣ、６Ｈ−ＳｉＣ、１５Ｒ−ＳｉＣ、３Ｃ−ＳｉＣの何れかを用いることが好ましい。   Arbitrary kinds can be used for the crystal polymorph (polytype) of silicon carbide of silicon carbide substrate 1. From the viewpoint that the polytype is relatively stable and a large-area substrate can be manufactured, it is preferable to use any of 4H—SiC, 6H—SiC, 15R—SiC, and 3C—SiC.

［水素終端処理］
次に、炭化珪素基板１をチャンバ内で水素を含むクリーニングガスで表面処理をする。具体的には、チャンバ内で、クリーニングガスを励起させてプラズマを生成し、プラズマ中の水素を炭化珪素基板１の主表面に作用させる。この表面処理により、炭化珪素基板１の主表面のダングリングボンドが水素で終端される。 [Hydrogen termination]
Next, the silicon carbide substrate 1 is surface-treated with a cleaning gas containing hydrogen in the chamber. Specifically, the cleaning gas is excited in the chamber to generate plasma, and hydrogen in the plasma is allowed to act on the main surface of silicon carbide substrate 1. By this surface treatment, dangling bonds on the main surface of silicon carbide substrate 1 are terminated with hydrogen.

なお、ここでいう水素を含むクリーニングガスとは、例えば、水素ガスや、ＨＣｌ、ＨＦなどのハロゲン化ガス、又はこれらの混合ガスをいう。また、他の表面処理としては、チャンバ内で炭化珪素基板１を高温のクリーニングガス下においてもよい。これによっても炭化珪素基板１の主表面のダングリングボンドが水素で終端される。   The cleaning gas containing hydrogen here refers to, for example, hydrogen gas, halogenated gas such as HCl and HF, or a mixed gas thereof. As another surface treatment, silicon carbide substrate 1 may be placed in a chamber under a high temperature cleaning gas. This also terminates dangling bonds on the main surface of silicon carbide substrate 1 with hydrogen.

［窒素終端処理］
次に、図１（ｂ）に示すように、炭化珪素基板１を窒素含有ガスで表面処理をする。この表面処理は、水素終端処理を行った後、同一チャンバ１０で連続的に行う。具体的には、窒素含有ガスを励起させてプラズマを生成し、プラズマ中の窒素を炭化珪素基板１の主表面に作用させる。この結果、炭化珪素基板１の主表面のダングリングボンドを終端した水素が、窒素で置換される。すなわち、炭化珪素基板１の主表面のダングリングボンドは、窒素で終端されたことになる。 [Nitrogen termination]
Next, as shown in FIG. 1B, the silicon carbide substrate 1 is surface-treated with a nitrogen-containing gas. This surface treatment is continuously performed in the same chamber 10 after the hydrogen termination treatment. Specifically, a nitrogen-containing gas is excited to generate plasma, and nitrogen in the plasma is allowed to act on the main surface of silicon carbide substrate 1. As a result, hydrogen that terminates dangling bonds on the main surface of silicon carbide substrate 1 is replaced with nitrogen. That is, dangling bonds on the main surface of silicon carbide substrate 1 are terminated with nitrogen.

なお、ここでいう窒素含有ガスは、例えば、窒素ガス、アンモニアガス（ＮＨ３）、一酸化窒素ガス（ＮＯ）、亜酸化窒素（Ｎ２Ｏ）、又はこれらの混合ガスをいう。また、他の表面処理としては、チャンバ内で炭化珪素基板１を高温の窒素含有ガス下においてもよい。これによっても炭化珪素基板１の主表面のダングリングボンドを終端した水素が窒素に置換される。 The nitrogen-containing gas here refers to, for example, nitrogen gas, ammonia gas (NH 3 ), nitrogen monoxide gas (NO), nitrous oxide (N 2 O), or a mixed gas thereof. As another surface treatment, silicon carbide substrate 1 may be placed in a chamber under a high-temperature nitrogen-containing gas. This also replaces hydrogen that terminates dangling bonds on the main surface of silicon carbide substrate 1 with nitrogen.

［絶縁膜作製処理］
次に、図２（ａ）に示すように、炭化珪素基板１の主表面上に絶縁膜２を作製する。絶縁膜２の作製に際しては、炭化珪素基板１を大気に露出させずに行う。すなわち、窒素終端処理をした炭化珪素基板１が自然酸化することを避けて絶縁膜２を作製する。具体的には、チャンバ１０で水素終端処理及び窒素終端処理を行った後、炭化珪素基板１をチャンバ１０の外に出さずに絶縁膜作製処理を行う。また、チャンバ１０で水素終端処理及び窒素終端処理を行った後、大気に触れないようにして絶縁膜２を作製するための別のチャンバに移送してもよい。 [Insulating film fabrication process]
Next, as shown in FIG. 2A, an insulating film 2 is formed on the main surface of silicon carbide substrate 1. The insulating film 2 is produced without exposing the silicon carbide substrate 1 to the atmosphere. That is, the insulating film 2 is produced while avoiding natural oxidation of the silicon carbide substrate 1 subjected to nitrogen termination. Specifically, after the hydrogen termination process and the nitrogen termination process are performed in the chamber 10, the insulating film manufacturing process is performed without taking the silicon carbide substrate 1 out of the chamber 10. Alternatively, after the hydrogen termination treatment and the nitrogen termination treatment are performed in the chamber 10, the chamber 10 may be transferred to another chamber for manufacturing the insulating film 2 without being exposed to the atmosphere.

絶縁膜２としては特に限定されないが、（１）ＳｉＯ２、（２）ＳｉＮとＳｉＯ２とが混合した膜、（３）Ａｌ２Ｏ３、（４）ＳｉＯ２とＡｌ２Ｏ３とが混合した酸化膜などが挙げられる。 No particular limitation is imposed on the insulating film 2, (1) SiO 2, (2) SiN and SiO 2 are mixed and membrane, and the (3) Al 2 O 3, (4) SiO 2 and Al 2 O 3 mixed Oxide film and the like.

（１）ＳｉＯ２については、熱酸化やＣＶＤ法により作製することができる。また、（２）〜（４）の各絶縁膜２については、ＣＶＤ法により作製することができる。なお、絶縁膜２を作製した後に、急速アニール処理（ＲＴＡ）を行ってもよい。すなわち、チャンバ内をアルゴン雰囲気又は窒素雰囲気にした上で急速加熱してもよい。 (1) For SiO 2 can be prepared by thermal oxidation or CVD. In addition, each of the insulating films 2 of (2) to (4) can be produced by a CVD method. Note that rapid annealing (RTA) may be performed after the insulating film 2 is formed. That is, rapid heating may be performed after setting the inside of the chamber to an argon atmosphere or a nitrogen atmosphere.

また、絶縁膜２としては、５ｎｍ以上であることが好ましい。これにより、電子デバイスの作製に適した厚さの絶縁膜２とすることができる。ちなみに、炭化珪素基板１上に自然酸化によりＳｉＯＮなどの酸化膜が出来たとしてもその厚みは５ｎｍ未満と薄く、電子デバイスの作製に適さない。   The insulating film 2 is preferably 5 nm or more. Thereby, it can be set as the insulating film 2 of the thickness suitable for manufacture of an electronic device. Incidentally, even if an oxide film such as SiON is formed on the silicon carbide substrate 1 by natural oxidation, the thickness is as thin as less than 5 nm, which is not suitable for manufacturing an electronic device.

以上の図１〜図２（ａ）に示した工程によれば、炭化珪素基板１上に絶縁膜２が作製された炭化珪素半導体素子が製造される。   According to the steps shown in FIGS. 1 to 2A, a silicon carbide semiconductor element in which insulating film 2 is formed on silicon carbide substrate 1 is manufactured.

［電子デバイス作製処理］
このようにして得られた炭化珪素半導体素子をベースに電子デバイスを作製する。すなわち、図２（ｂ）に示すように、炭化珪素基板１上に作製された絶縁膜２に、パターニング等の各種プロセスを実施して、電子デバイス３を作製する。 [Electronic device fabrication process]
An electronic device is produced based on the silicon carbide semiconductor element thus obtained. That is, as shown in FIG. 2B, the electronic device 3 is manufactured by performing various processes such as patterning on the insulating film 2 formed on the silicon carbide substrate 1.

［本発明の効果］
本実施形態に係る製造方法により得られた炭化珪素半導体素子（実施例）と、炭化珪素基板上に、水素終端処理及び窒素終端処理を行わずに絶縁膜を作製することにより得られた炭化珪素半導体素子（比較例）について、界面欠陥密度の比較を行った。図３にエネルギー準位（Ｅｃ−Ｅ（ｅＶ））と界面欠陥密度との関係を示す。横軸はエネルギー準位であり、縦軸は界面欠陥密度を示す。また、図中の○は比較例であり、△は実施例を示す。 [Effect of the present invention]
Silicon carbide semiconductor element (Example) obtained by the manufacturing method according to the present embodiment, and silicon carbide obtained by producing an insulating film on a silicon carbide substrate without performing hydrogen termination treatment and nitrogen termination treatment The interface defect density was compared for the semiconductor element (comparative example). FIG. 3 shows the relationship between the energy level (Ec-E (eV)) and the interface defect density. The horizontal axis represents the energy level, and the vertical axis represents the interface defect density. Moreover, (circle) in a figure is a comparative example and (triangle | delta) shows an Example.

同図に示すように、どのエネルギー準位においても、実施例は、比較例よりも界面欠陥密度が低下している。すなわち、本実施形態に係る製造方法により、炭化珪素基板１の表面と絶縁膜２との界面に窒素が導入され、高品質な界面と絶縁膜が得られることが分かる。   As shown in the figure, the interface defect density in the example is lower than that in the comparative example at any energy level. That is, it can be seen that the manufacturing method according to the present embodiment introduces nitrogen into the interface between the surface of the silicon carbide substrate 1 and the insulating film 2 to obtain a high-quality interface and insulating film.

以上に説明した炭化珪素半導体素子の製造方法によれば、炭化珪素基板１の主表面に存在していたダングリングボンドが窒素で終端され、炭化珪素基板１の主表面と絶縁膜２との界面に窒素が存在する炭化珪素半導体素子が作製される。   According to the method for manufacturing a silicon carbide semiconductor element described above, dangling bonds existing on the main surface of silicon carbide substrate 1 are terminated with nitrogen, and the interface between main surface of silicon carbide substrate 1 and insulating film 2 A silicon carbide semiconductor element in which nitrogen is present is produced.

このように作製された炭化珪素半導体素子は、ダングリングボンドが窒素で終端されたことにより、界面には欠陥が無く、リーク電流の発生を抑えることができる。また、界面に存在する窒素により界面準位密度が低減され、高品質な界面及び絶縁膜２が得られる。このような界面準位密度が低減した炭化珪素半導体素子からは、例えば、チャネル移動度が向上し、炭化珪素の優れた物性を生かした炭化珪素ＭＯＳＦＥＴなどの電子デバイスを作製することができる。また、絶縁膜２は、電子デバイスを作製するのに適した膜厚とすることができる。   In the silicon carbide semiconductor device manufactured in this manner, dangling bonds are terminated with nitrogen, so that there is no defect at the interface and generation of leakage current can be suppressed. Further, the interface state density is reduced by nitrogen existing at the interface, and a high-quality interface and the insulating film 2 are obtained. From such a silicon carbide semiconductor element having a reduced interface state density, for example, an electronic device such as a silicon carbide MOSFET that improves channel mobility and makes use of the excellent physical properties of silicon carbide can be produced. Moreover, the insulating film 2 can be made into a film thickness suitable for manufacturing an electronic device.

［その他のバリエーション］
上述した実施形態においては、一連の処理を同一のチャンバ内で炭化珪素基板を取り出すことなく、連続的に行った。これにより、電子デバイス３を作製するまでの工程を合理的に行うことができる。 [Other variations]
In the embodiment described above, a series of processes were continuously performed without taking out the silicon carbide substrate in the same chamber. Thereby, the process until the electronic device 3 is manufactured can be rationally performed.

また、同一チャンバ内で連続的に処理する場合に限らず、例えば、クリーニングガス及び窒素含有ガスでの表面処理と、絶縁膜２を作製する工程とを別のチャンバで行ってもよい。この製法は、絶縁膜２を作製する工程において、その前の表面処理で用いたガスの影響を極力避けたい場合に有効である。また、水素終端処理、窒素終端処理、絶縁膜作製処理は全て異なるチャンバで行ってもよい。いずれにせよ、窒素終端処理のあと、炭化珪素基板１が自然酸化しないようにして、絶縁膜作製処理を行う。   In addition, the processing is not limited to the case where the processing is continuously performed in the same chamber, and for example, the surface treatment with the cleaning gas and the nitrogen-containing gas and the step of manufacturing the insulating film 2 may be performed in different chambers. This manufacturing method is effective when it is desired to avoid the influence of the gas used in the previous surface treatment as much as possible in the process of manufacturing the insulating film 2. In addition, the hydrogen termination process, the nitrogen termination process, and the insulating film manufacturing process may all be performed in different chambers. In any case, after the nitrogen termination process, the insulating film forming process is performed so that the silicon carbide substrate 1 is not naturally oxidized.

さらに、窒素含有ガスによる表面処理を一つの工程として実施したがこれに限らない。例えば、絶縁膜２としてＣＶＤ法でＳｉＮを作製する場合、ＳｉＮの堆積と共に炭化珪素基板の主表面のダングリングボンドが窒素で終端されることが期待できる。このように、窒素含有ガスによる表面処理は、絶縁膜２の作製と同時的に行ってもよい。   Furthermore, although the surface treatment by nitrogen-containing gas was implemented as one process, it is not restricted to this. For example, when SiN is produced as the insulating film 2 by the CVD method, it can be expected that dangling bonds on the main surface of the silicon carbide substrate are terminated with nitrogen as SiN is deposited. As described above, the surface treatment with the nitrogen-containing gas may be performed simultaneously with the production of the insulating film 2.

本発明は、炭化珪素半導体素子を利用する産業分野で利用することができる。   The present invention can be used in an industrial field using a silicon carbide semiconductor element.

１ 炭化珪素基板
２ 絶縁膜
３ 電子デバイス
１０ チャンバ DESCRIPTION OF SYMBOLS 1 Silicon carbide substrate 2 Insulating film 3 Electronic device 10 Chamber

Claims (5)

水素を含むクリーニングガスを励起させてプラズマを生成し、プラズマ中の水素により炭化珪素の主表面のダングリングボンドを終端させ、
窒素含有ガスを励起させてプラズマを生成し、酸化膜を形成せずにプラズマ中の窒素により前記主表面のダングリングボンドを終端した水素を窒素で置換した後、
前記主表面上に酸化膜を形成する
ことを特徴とする炭化珪素半導体素子の製造方法。 A cleaning gas containing hydrogen is excited to generate plasma, and dangling bonds on the main surface of silicon carbide are terminated by hydrogen in the plasma,
A plasma is generated by exciting a nitrogen-containing gas, and after replacing dangling bonds on the main surface with nitrogen by nitrogen in the plasma without forming an oxide film ,
An oxide film is formed on the main surface. A method for manufacturing a silicon carbide semiconductor element. 請求項１に記載する炭化珪素半導体素子の製造方法において、
クリーニングガスで表面処理し、窒素含有ガスで表面処理し、主表面上に酸化膜を形成する工程を、同一のチャンバ内で連続的に行う
ことを特徴とする炭化珪素半導体素子の製造方法。 In the manufacturing method of the silicon carbide semiconductor element of Claim 1,
A method for manufacturing a silicon carbide semiconductor device, wherein the steps of surface treatment with a cleaning gas, surface treatment with a nitrogen-containing gas, and formation of an oxide film on a main surface are continuously performed in the same chamber. 請求項１に記載する炭化珪素半導体素子の製造方法において、
主表面上に酸化膜を形成する工程は、クリーニングガス及び窒素含有ガスの表面処理とは別のチャンバで行う
ことを特徴とする炭化珪素半導体素子の製造方法。 In the manufacturing method of the silicon carbide semiconductor element of Claim 1,
The method of manufacturing a silicon carbide semiconductor device, wherein the step of forming the oxide film on the main surface is performed in a chamber different from the surface treatment of the cleaning gas and the nitrogen-containing gas. 請求項１〜請求項３の何れか一項に記載する炭化珪素半導体素子の製造方法において、
前記酸化膜の厚さを５ｎｍ以上とする
ことを特徴とする炭化珪素半導体素子の製造方法。 In the manufacturing method of the silicon carbide semiconductor element as described in any one of Claims 1-3,
The method for manufacturing a silicon carbide semiconductor element, wherein the thickness of the oxide film is 5 nm or more. 炭化珪素上に形成された酸化膜を含む電子デバイスの製造方法であって、
請求項１〜請求項４の何れか一項に記載された製造方法によって前記酸化膜を形成することを特徴とする電子デバイスの製造方法。 A method of manufacturing an electronic device including an oxide film formed on silicon carbide,
5. A method of manufacturing an electronic device, wherein the oxide film is formed by the manufacturing method according to claim 1.
JP2010217756A 2010-09-28 2010-09-28 Method for manufacturing silicon carbide semiconductor element and method for manufacturing electronic device Active JP5656216B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2010217756A JP5656216B2 (en) 2010-09-28 2010-09-28 Method for manufacturing silicon carbide semiconductor element and method for manufacturing electronic device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2010217756A JP5656216B2 (en) 2010-09-28 2010-09-28 Method for manufacturing silicon carbide semiconductor element and method for manufacturing electronic device

Publications (2)

Publication Number Publication Date
JP2012074513A JP2012074513A (en) 2012-04-12
JP5656216B2 true JP5656216B2 (en) 2015-01-21

Family

ID=46170390

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2010217756A Active JP5656216B2 (en) 2010-09-28 2010-09-28 Method for manufacturing silicon carbide semiconductor element and method for manufacturing electronic device

Country Status (1)

Country Link
JP (1) JP5656216B2 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5524103B2 (en) 2011-02-07 2014-06-18 株式会社東芝 Semiconductor device
JP2013008894A (en) * 2011-06-27 2013-01-10 Saitama Univ Mos structure using silicon carbide semiconductor and oxide film forming method for the same
JP6162388B2 (en) * 2012-11-14 2017-07-12 新日本無線株式会社 Method for manufacturing silicon carbide semiconductor device
DE102013112785B3 (en) 2013-11-19 2015-02-26 Aixatech Gmbh Method for producing a composite body with at least one functional layer or for further production of electronic or opto-electronic components
JP5763154B2 (en) * 2013-11-20 2015-08-12 株式会社東芝 Semiconductor device and manufacturing method thereof
CN112522781B (en) * 2021-02-18 2021-04-23 中芯集成电路制造(绍兴)有限公司 Buffer layer on silicon carbide substrate and method of forming the same

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11168097A (en) * 1997-12-04 1999-06-22 Hitachi Ltd Manufacture of semiconductor device
JPH11297712A (en) * 1998-04-10 1999-10-29 Sanyo Electric Co Ltd Formation method for compound film and manufacture of semiconductor element
JP2001077112A (en) * 1999-07-07 2001-03-23 Matsushita Electric Ind Co Ltd Laminate, manufacture of thereof, and semiconductor element
JP4273142B2 (en) * 2005-08-12 2009-06-03 キヤノン株式会社 Surface treatment method, semiconductor device manufacturing method, and capacitive element manufacturing method
JP2008117878A (en) * 2006-11-02 2008-05-22 Mitsubishi Electric Corp Manufacturing method for semiconductor device
JP2008182070A (en) * 2007-01-25 2008-08-07 Toyota Motor Corp Method for forming silicon oxide layer
JP4765125B2 (en) * 2008-01-30 2011-09-07 Ｔａｎａｋａホールディングス株式会社 Multilayer substrate for forming multilayer printed wiring board and multilayer printed wiring board

Also Published As

Publication number Publication date
JP2012074513A (en) 2012-04-12

Similar Documents

Publication Publication Date Title
JP5656216B2 (en) Method for manufacturing silicon carbide semiconductor element and method for manufacturing electronic device
KR101245899B1 (en) Method of manufacturing silicon carbide semiconductor device
JP4526484B2 (en) Field effect transistor and manufacturing method thereof
JP5584823B2 (en) Silicon carbide semiconductor device
JP5344873B2 (en) Method for manufacturing silicon carbide semiconductor device
JP5733623B2 (en) Manufacturing method of semiconductor device
CN102804349A (en) Silicon carbide semiconductor device, and process for production thereof
TW200926303A (en) Semiconductor device manufacturing method and semiconductor device
CN1606140A (en) Silicon carbide-oxide layered structure, production method thereof, and semiconductor device
JP2005166930A (en) Sic-misfet and its manufacturing method
JP2010502031A (en) Method for improving inversion layer mobility in silicon carbide MOSFETs
JP2011091186A (en) Method of fabricating silicon carbide semiconductor device
JP4549167B2 (en) Method for manufacturing silicon carbide semiconductor device
KR20040014978A (en) Method for improving inversion layer mobility in a silicon carbide metal-oxide semiconductor field-effect transistor
JP2018035051A (en) SiC STRUCTURE AND PRODUCTION METHOD OF THE SAME, AND SEMICONDUCTOR DEVICE
JP2003243653A (en) Method for manufacturing silicon carbide semiconductor device
JP5997258B2 (en) Stacked substrate of silicon single crystal and group III nitride single crystal having off-angle, and method for manufacturing the same
CN108257858A (en) A kind of preparation method of high-k gate dielectric layer and silicon carbide mos power device
JP2009212366A (en) Method of manufacturing semiconductor device
JP5728153B2 (en) Manufacturing method of semiconductor device
JP5266996B2 (en) Semiconductor device manufacturing method and semiconductor device
JP2008182070A (en) Method for forming silicon oxide layer
WO2016204112A1 (en) Silicon carbide semiconductor device and production method for same
TWI719085B (en) Methods and solutions for cleaning ingaas (or iii-v) substrates
JP6162388B2 (en) Method for manufacturing silicon carbide semiconductor device

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20130805

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20140220

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20140305

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20140502

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20140709

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20141008

A911 Transfer to examiner for re-examination before appeal (zenchi)

Free format text: JAPANESE INTERMEDIATE CODE: A911

Effective date: 20141024

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: 20141119

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20141119

R150 Certificate of patent or registration of utility model

Ref document number: 5656216

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250