JP2006237065A

JP2006237065A - Method of manufacturing semiconductor device

Info

Publication number: JP2006237065A
Application number: JP2005045468A
Authority: JP
Inventors: Hidenori Takahashi; 英紀高橋
Original assignee: Fuji Electric Device Technology Co Ltd
Current assignee: Fuji Electric Co Ltd
Priority date: 2005-02-22
Filing date: 2005-02-22
Publication date: 2006-09-07

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor device which can improve film quality, even if an oxide film is embedded into a thick film having a film thickness not less than a film thickness not influenced by a film quality improving effect by thermal treatment in an oxygen atmosphere after a TEOS (tetraethylorthosilicate) oxide film is formed or into a deep trench structure. <P>SOLUTION: The method of manufacturing a semiconductor device is provided with a film forming process of using a TEOS gas to deposit and form a TEOS oxide film on a semiconductor substrate by a chemical vapor deposition, and an oxygen-containing layer forming process of supplying an oxygen gas after discharging the TEOS gas to laminate and form an oxygen-containing layer on the TEOS oxide film. After the above processes, the method is provided with a process of repeating the TEOS oxide film forming process and the oxygen-containing layer forming process at a plurality of times until the oxide film has a required thickness, and a process of thermally diffusing an oxygen into the TEOS oxide film by heating. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、有機系ソースガスであるＴＥＯＳ（ＴｅｔｒａＥｔｈｙｌＯｒｔｈｏＳｉｌｉｃａｔｅ−テトラエトキシシラン：Ｓｉ（Ｃ２Ｈ５Ｏ）_４）を用いて、減圧ＣＶＤ法（ＣＶＤ＝ＣｈｅｍｉｃａｌＶａｐｏｒＤｅｐｏｓｉｔｉｏｎ、化学的気相成長）により形成するＴＥＯＳ酸化膜の成膜方法およびそのＴＥＯＳ酸化膜の膜質の改善方法にかかり、改善されたＴＥＯＳ酸化膜を用いた半導体装置の製造方法に関するものである。 The present invention uses TEOS (Tetra Ethyl Ortho Silicate-tetraethoxysilane: Si (C 2 H ₅ O) ₄ ), which is an organic source gas, to form TEOS formed by low pressure CVD (CVD = Chemical Vapor Deposition, chemical vapor deposition). The present invention relates to a method for forming an oxide film and a method for improving the film quality of the TEOS oxide film, and to a method for manufacturing a semiconductor device using the improved TEOS oxide film.

半導体装置の高集積化に伴い、シリコン半導体基板（シリコンウエハ）においては、隣接する素子間を絶縁分離するための素子分離領域のさらなる微細化、あるいは隣接する配線間または配線層間を絶縁分離するための絶縁分離領域等のさらなる微細化が望まれている。さらには、より微細で深い溝領域への絶縁層の埋め込み技術と、埋め込まれた絶縁層の膜質改善による絶縁性能の向上が求められている。
このような状況の下、酸化膜形成用の有機系ソースガスであるＴＥＯＳ（テトラエトキシシラン：Ｓｉ（Ｃ２Ｈ５Ｏ）_４）を用いた減圧ＣＶＤ法により形成したＴＥＯＳ酸化膜は、モノシラン系ガス（ＳｉＨ４を含むガス）を用いて形成された酸化膜であるＨＴＯ（ＨｉｇｈＴｅｍｐｅｒａｔｕｒｅＯｘｉｄｅ）酸化膜と比較すると、利点として、
（１）カバレッジ（被覆性）がより良好であること、
（２）成膜速度が大きく、生産効率が高いこと、
（３）ウエハ面内における膜質の良好な均一性が、膜形成用装置の構成の複雑化を伴うことなく、比較的容易に得られること、
（４）一般的な成膜温度が６００℃から７００℃の温度範囲であり、ＨＴＯ酸化膜に比してプロセス温度の低温化を図ることができること、
等を有している。 Along with higher integration of semiconductor devices, in a silicon semiconductor substrate (silicon wafer), in order to further miniaturize element isolation regions for insulating and isolating adjacent elements, or to insulate and isolate adjacent wirings or wiring layers. Further miniaturization of the insulating isolation region is desired. Furthermore, there is a need for a technique for embedding an insulating layer in a finer and deeper groove region and an improvement in insulation performance by improving the film quality of the buried insulating layer.
Under such circumstances, the TEOS oxide film formed by the low pressure CVD method using TEOS (tetraethoxysilane: Si (C 2 H ₅ O) ₄ ), which is an organic source gas for forming an oxide film, is formed of a monosilane-based gas (SiH 4 As compared with an HTO (High Temperature Oxide) oxide film that is an oxide film formed using a gas containing
(1) The coverage (coverability) is better.
(2) High deposition rate and high production efficiency.
(3) Good uniformity of film quality within the wafer surface can be obtained relatively easily without complicating the configuration of the film forming apparatus,
(4) The general film formation temperature is in the temperature range of 600 ° C. to 700 ° C., and the process temperature can be lowered as compared with the HTO oxide film.
Etc.

しかしながら、欠点として
（１）プロセス温度が低いために、膜が緻密でなく、エッチングレートが大きい。このため、加工における制御性が悪いこと、
（２）膜中のＳｉ原子とＯ原子間の結合が不完全であることに起因する構造欠陥が多数存在するため、酸化膜としての絶縁性が低いこと、
（３）有機系のソースガスを原料としているために、膜中にＣ原子、Ｈ原子、Ｏ原子を含む炭化水素系化合物などの高濃度の不純物が残存し、変動しやすい膜中電荷となり易い。この結果、ＴＥＯＳ酸化膜を、例えば、素子領域を被覆する層間絶縁膜として適用した場合、その下層に配置した素子特性に変動を引き起こすことがある。
素子特性の変動のような前記欠点を解消して素子特性の高精度化を図るためには、ＴＥＯＳ酸化膜を信頼性の高い膜質に改善することが求められている。 However, the disadvantages are (1) because the process temperature is low, the film is not dense and the etching rate is high. For this reason, controllability in processing is poor,
(2) Since there are many structural defects due to imperfect bonding between Si atoms and O atoms in the film, the insulating property as an oxide film is low,
(3) Since an organic source gas is used as a raw material, high-concentration impurities such as hydrocarbon compounds containing C atoms, H atoms, and O atoms remain in the film, and the film charges easily change. . As a result, when the TEOS oxide film is applied as, for example, an interlayer insulating film that covers the element region, the element characteristics arranged in the lower layer may be changed.
In order to eliminate the above-mentioned drawbacks such as variations in device characteristics and to improve the accuracy of device characteristics, it is required to improve the TEOS oxide film to a highly reliable film quality.

一般に、ＴＥＯＳ酸化膜を含むＣＶＤ酸化膜の膜質改善を図る方法としては、窒素等の不活性ガス雰囲気中で熱処理を行うことにより、膜の緻密化を図ることが通常行われている。この方法によれば、ＴＥＯＳ酸化膜のエッチングレートは低く抑えられ、加えて絶縁性としては、ＨＴＯ酸化膜と同程度の性能を有するまでに改善することが可能となる。
一方、前述したような窒素雰囲気による熱処理だけでは、素子の信頼性特性について、前述したＨＴＯ酸化膜と同程度にまで改善することはできず、必ずしも充分に満足できる解決策とは言えないことも明らかになってきた。その理由は素子特性の経時変動や長期信頼性等に影響を及ぼす膜中電荷について、前述の窒素雰囲気中での熱処理が充分有効とは言えないからである。
他方、酸素雰囲気中で熱処理を行うと、前述のＴＥＯＳ酸化膜のエッチングレートと絶縁性能の改善に加え、さらに膜中電荷についてもＨＴＯ酸化膜と同程度にまで低減できることは、既に公知の技術でもある（特許文献１−課題および解決手段、特許文献２−作用の項）。ＴＥＯＳ酸化膜中への酸素導入による膜質の改善効果について、以下、詳しく説明する。図５、図６は、それぞれ窒素雰囲気と酸素雰囲気で、膜厚０．１μｍを有するＴＥＯＳ酸化膜を同一温度、時間で熱処理したＴＥＯＳ酸化膜成膜基板の絶縁性能を評価するＩ−Ｖ特性図であり、図７、図８は、それぞれ窒素雰囲気と酸素雰囲気で、膜厚０．１μｍを有するＴＥＯＳ酸化膜を同一温度、時間で熱処理したＴＥＯＳ酸化膜成膜基板の膜中電荷を評価するＣ−Ｖ特性図である。 In general, as a method for improving the film quality of a CVD oxide film including a TEOS oxide film, a film is usually densified by performing a heat treatment in an inert gas atmosphere such as nitrogen. According to this method, the etching rate of the TEOS oxide film can be kept low, and in addition, the insulating property can be improved to the same level as the HTO oxide film.
On the other hand, only the heat treatment in the nitrogen atmosphere as described above cannot improve the reliability characteristics of the device to the same level as the HTO oxide film described above, and is not necessarily a satisfactory solution. It has become clear. The reason for this is that the heat treatment in the nitrogen atmosphere described above cannot be said to be sufficiently effective with respect to the charge in the film which affects the device characteristics over time and long-term reliability.
On the other hand, when heat treatment is performed in an oxygen atmosphere, in addition to the improvement of the etching rate and insulation performance of the TEOS oxide film, the charge in the film can be reduced to the same level as that of the HTO oxide film. Yes (Patent Document 1—Problems and Solution, Patent Document 2—Action Section). The effect of improving the film quality by introducing oxygen into the TEOS oxide film will be described in detail below. 5 and 6 are IV characteristic diagrams for evaluating the insulating performance of a TEOS oxide film-formed substrate obtained by heat-treating a TEOS oxide film having a thickness of 0.1 μm at the same temperature and time in a nitrogen atmosphere and an oxygen atmosphere, respectively. 7 and 8 evaluate the charge in the film of a TEOS oxide film-formed substrate obtained by heat-treating a TEOS oxide film having a thickness of 0.1 μm at the same temperature and time in a nitrogen atmosphere and an oxygen atmosphere, respectively. FIG.

図５、図６のＩ−Ｖ特性図から絶縁性能を比較すると、例えば、ＴＥＯＳ酸化膜厚０．１μｍに対し、電圧を徐々に印加し、リーク電流が１ｍＡを越える電圧を破壊電圧とした場合、両者とも８０Ｖ程度となる。この値は、１ｃｍの厚さに換算すると、１ｍＡ時の耐圧としては８ＭＶ／ｃｍ程度となり、共に絶縁性能としては良好であってＩ−Ｖ特性（波形）上にも大きな違いは見られない。この絶縁性能に関しては、図９に示すＨＴＯ酸化膜成膜基板のＩ−Ｖ特性と比較しても、酸素および窒素雰囲気中のいずれの場合も、ほとんど差がないことが分かる。
一方、図７、図８のＣ−Ｖ特性図から膜中電荷を比較すると、窒素雰囲気で熱処理を行った図７では、Ｃ−Ｖ曲線にヒステリシスが見られ、シフト量が大きいのに対し、酸素雰囲気で熱処理を行った図８では、ヒステリシス、Ｃ−Ｖシフトともに見られず、さらに図１０に示すＨＴＯ酸化膜の場合のＣ−Ｖ特性と比較しても、差がないことが分かる。 When comparing the insulation performance from the IV characteristic diagrams of FIGS. 5 and 6, for example, when a voltage is gradually applied to a TEOS oxide film thickness of 0.1 μm, and a voltage with a leakage current exceeding 1 mA is used as a breakdown voltage. Both are about 80V. When converted to a thickness of 1 cm, this value is about 8 MV / cm as the withstand voltage at 1 mA, and both have good insulation performance, and there is no significant difference in IV characteristics (waveform). With respect to this insulation performance, it can be seen that there is almost no difference between the IV characteristics of the HTO oxide film deposition substrate shown in FIG.
On the other hand, when the charge in the film is compared from the CV characteristic diagrams of FIGS. 7 and 8, in FIG. 7 where the heat treatment is performed in a nitrogen atmosphere, hysteresis is seen in the CV curve and the shift amount is large. In FIG. 8 in which heat treatment is performed in an oxygen atmosphere, neither hysteresis nor CV shift is observed, and it can be seen that there is no difference even when compared with the CV characteristics in the case of the HTO oxide film shown in FIG.

また、素子分離用のＳＴＩ（ＳｈａｌｌｏｗＴｒｅｎｃｈＩｓｏｌａｔｉｏｎ）に埋め込まれるＴＥＯＳ酸化膜の場合の膜質改善について、ＴＥＯＳ酸化膜を水蒸気雰囲気中で加熱処理すると、厚さ１μｍ程度まで、膜質改善効果が及ぶことが記載された文献が知られている（特許文献３、段落０００８〜段落００１０）。
特開平３−２０１４３５号公報特開平７−２４５２６７号公報特開２００１−７７１０５号公報 In addition, regarding the film quality improvement in the case of a TEOS oxide film embedded in an STI (Shallow Trench Isolation) for element isolation, if the TEOS oxide film is heat-treated in a water vapor atmosphere, the film quality improvement effect may reach a thickness of about 1 μm. The document described is known (patent document 3, paragraphs 0008 to 0010).
Japanese Patent Laid-Open No. 3-201435 JP-A-7-245267 JP 2001-77105 A

しかしながら、前述の酸素雰囲気での加熱による膜質改善方法では、例えば、膜厚が０．２μｍ未満程度のように比較的薄い場合には、酸素がＴＥＯＳ酸化膜中を均等に十分拡散し、膜質の改善が確実に行われ、良好な効果をもたらすが、膜厚が０．５μｍ以上と厚い場合には、酸素がＴＥＯＳ酸化膜中の表面近傍付近のみの拡散にとどまることにより、深さ方向に対する膜質の改善が確実に行われ難いという問題がある。また前記特許文献３に記載の水蒸気雰囲気の加熱処理によれば、厚さ１μｍまで膜質が改善されるが、それ以上の厚さの場合について、調べたところ、従来と同様な問題のあることが分かった。特に、図１１に示すように、深さ１．０μｍを超える深さのトレンチ溝１３内にＴＥＯＳ酸化膜１８を埋め込む工程を行う場合、その膜質改善を酸素雰囲気での加熱処理により充分に行うことは、トレンチ１３内に埋め込まれた酸化膜の有効な深さ方向の厚さも、前述のように１．０μｍ以上のように著しく厚くなってしまうので、熱処理により酸素１９が拡散し得るＴＥＯＳ酸化膜１７の厚さはトレンチ溝１３の底にまで届かず、全ＴＥＯＳ酸化膜の確実な膜質改善を行うことはとうてい不可能と言わざるを得なかった。 However, in the film quality improvement method by heating in the above-described oxygen atmosphere, for example, when the film thickness is relatively thin, such as less than about 0.2 μm, oxygen diffuses uniformly and sufficiently in the TEOS oxide film, and the film quality is improved. Improvement is ensured and brings about a good effect, but when the film thickness is as thick as 0.5 μm or more, the oxygen remains only in the vicinity of the surface in the TEOS oxide film, so that the film quality in the depth direction There is a problem that it is difficult to improve. Further, according to the heat treatment in the water vapor atmosphere described in Patent Document 3, the film quality is improved to a thickness of 1 μm, but when the thickness is more than that, there is a problem similar to the conventional one. I understood. In particular, as shown in FIG. 11, when the step of embedding the TEOS oxide film 18 in the trench groove 13 having a depth exceeding 1.0 μm is performed, the film quality should be sufficiently improved by heat treatment in an oxygen atmosphere. Since the effective depth direction thickness of the oxide film buried in the trench 13 is remarkably increased to 1.0 μm or more as described above, the TEOS oxide film in which oxygen 19 can diffuse by heat treatment. The thickness of 17 did not reach the bottom of the trench groove 13, and it was impossible to reliably improve the film quality of all the TEOS oxide films.

本発明は、以上述べた点に鑑みてなされたものであり、ＣＶＤ法により形成されるＴＥＯＳ酸化膜形成後における酸素雰囲気での熱処理による膜質改善効果の及ばない膜厚以上に厚膜化を図る場合や、前記膜質改善効果の及ばない膜厚より深いトレンチ構造に酸化膜を埋め込む場合であっても、埋め込み酸化膜の膜質を改善し、素子特性を改善できる半導体装置の製造方法を提供することを目的とする。 The present invention has been made in view of the above points, and is intended to increase the film thickness beyond the film quality improvement effect by heat treatment in an oxygen atmosphere after the formation of the TEOS oxide film formed by the CVD method. To provide a method for manufacturing a semiconductor device capable of improving the film quality of a buried oxide film and improving element characteristics even when the oxide film is buried in a trench structure deeper than the film thickness that does not reach the film quality improvement effect. With the goal.

特許請求の範囲の請求項１記載の本発明によれば、ＴＥＯＳ（ＴｅｔｒａＥｔｈｙｌＯｒｔｈｏＳｉｌｉｃａｔｅ）ガスを用いて化学的気相成長法（ＣＶＤ法）によりＴＥＯＳ酸化膜を堆積形成する成膜工程と、前記ＴＥＯＳガスの排気後、酸素ガスを供給して前記ＴＥＯＳ酸化膜上部に前記ＴＥＯＳ酸化膜の酸素濃度を高濃度にさせた酸素含有層形成工程とを複数回繰り返した後、加熱により前記ＴＥＯＳ酸化膜中に酸素を熱拡散させる酸素拡散用熱処理工程を備える半導体装置の製造方法とすることにより、前記本発明の目的は達成される。
特許請求の範囲の請求項２記載の本発明によれば、前記成膜工程における一回の膜厚は、５０から２００ｎｍである特許請求の範囲の請求項１記載の半導体装置の製造方法とすることが好ましい。 According to the first aspect of the present invention, a film forming step of depositing and forming a TEOS oxide film by a chemical vapor deposition method (CVD method) using TEOS (Tetra Ethyl Ortho Silicate) gas; After exhausting the TEOS gas, an oxygen-containing layer forming step in which oxygen gas is supplied to increase the oxygen concentration of the TEOS oxide film on the TEOS oxide film is repeated a plurality of times, and then the TEOS oxide film is heated. The object of the present invention is achieved by providing a semiconductor device manufacturing method including an oxygen diffusion heat treatment step in which oxygen is thermally diffused.
According to the present invention as set forth in claim 2, the semiconductor device manufacturing method according to claim 1, wherein the film thickness at one time in the film forming step is 50 to 200 nm. It is preferable.

特許請求の範囲の請求項３記載の本発明によれば、前記成膜工程と酸素含有層形成工程とは、同一真空処理装置内で連続して行われる特許請求の範囲の請求項１または２記載の半導体装置の製造方法とすることがより好ましい。
特許請求の範囲の請求項４記載の本発明によれば、前記成膜工程と、酸素含有層形成工程と、前記両工程後に行われる酸素拡散用熱処理工程とは、前記同一真空処理装置内で連続して行われる特許請求の範囲の請求項１乃至３のいずれか一項に記載の半導体装置の製造方法。
特許請求の範囲の請求項５記載の本発明によれば、前記成膜工程の成膜温度範囲は、６００℃乃至７５０℃である特許請求の範囲の請求項１乃至４のいずれか一項に記載の半導体装置の製造方法とすることがいっそう好ましい。 According to the third aspect of the present invention, the film forming step and the oxygen-containing layer forming step are performed continuously in the same vacuum processing apparatus. More preferably, the manufacturing method of the semiconductor device described is used.
According to the present invention of claim 4, the film forming step, the oxygen-containing layer forming step, and the oxygen diffusion heat treatment step performed after both steps are performed in the same vacuum processing apparatus. 4. The method of manufacturing a semiconductor device according to claim 1, wherein the method is performed continuously.
According to the present invention as set forth in claim 5, the film forming temperature range of the film forming step is 600 ° C. to 750 ° C. According to any one of claims 1 to 4. More preferably, the method of manufacturing a semiconductor device described above is used.

特許請求の範囲の請求項６記載の本発明によれば、前記成膜工程の圧力範囲は、０．１Ｔｏｒｒ（１Ｔｏｒｒ＝１３３．３Ｐａ）乃至３Ｔｏｒｒの圧力範囲である特許請求の範囲の請求項１乃至５のいずれか一項に記載の半導体装置の製造方法とすることが望ましい。
特許請求の範囲の請求項７記載の本発明によれば、前記酸素含有層形成工程は、酸素ガスを０．１ｓｌｍ乃至４０ｓｌｍの流量範囲で供給する特許請求の範囲の請求項１乃至６のいずれか一項に記載の半導体装置の製造方法とすることがより望ましい。
特許請求の範囲の請求項８記載の本発明によれば、前記酸素拡散用熱処理工程の温度範囲は、８００℃乃至１０００℃である特許請求の範囲の請求項１乃至７のいずれか一項に記載の半導体装置の製造方法ことがいっそう望ましい。 According to the present invention of claim 6, the pressure range of the film forming step is a pressure range of 0.1 Torr (1 Torr = 133.3 Pa) to 3 Torr. It is desirable to use the method for manufacturing a semiconductor device according to any one of items 1 to 5.
According to the present invention as set forth in claim 7, the oxygen-containing layer forming step supplies oxygen gas in a flow rate range of 0.1 slm to 40 slm. It is more desirable to use the method for manufacturing a semiconductor device according to any one of the above.
According to the present invention as set forth in claim 8, the temperature range of the heat treatment step for oxygen diffusion is from 800 ° C. to 1000 ° C. The method of manufacturing a semiconductor device described is more desirable.

特許請求の範囲の請求項９記載の本発明によれば、前記酸素拡散用熱処理工程は、不活性ガス含有雰囲気中で行われる特許請求の範囲の請求項１乃至８のいずれか一項に記載の半導体装置の製造方法とすることが好適である。
特許請求の範囲の請求項１０記載の本発明によれば、前記酸素拡散用熱処理工程は、酸素雰囲気中で行われる特許請求の範囲の請求項１乃至８のいずれか一項に記載の半導体装置の製造方法とすることが好適である。
特許請求の範囲の請求項１１記載の本発明によれば、前記酸素拡散用熱処理工程は、不活性ガスと酸素の混合雰囲気中で行われる特許請求の範囲の請求項１乃至８のいずれか一項に記載の半導体装置の製造方法が好ましい。 According to the present invention as set forth in claim 9, the oxygen diffusion heat treatment step is performed in an inert gas-containing atmosphere, according to any one of claims 1 to 8. It is preferable to use the manufacturing method of the semiconductor device.
According to a tenth aspect of the present invention, in the semiconductor device according to any one of the first to eighth aspects, the oxygen diffusion heat treatment step is performed in an oxygen atmosphere. It is preferable to use this manufacturing method.
According to the present invention as set forth in claim 11, the oxygen diffusion heat treatment step is performed in a mixed atmosphere of an inert gas and oxygen. The method for manufacturing a semiconductor device described in the item is preferable.

本発明によればＣＶＤ法により形成するＴＥＯＳ酸化膜形成後における酸素雰囲気での熱処理による膜質改善効果の及ばない膜厚以上に厚膜化を図る場合や、前記膜質改善効果の及ばない膜厚より深いトレンチ構造に酸化膜を埋め込む場合であっても、埋め込み酸化膜の膜質を改善し、素子特性を改善する半導体装置の製造方法を提供できる。
以上のように、本発明にかかるＴＥＯＳ酸化膜の成膜方法およびその酸化膜の膜質改善方法によれば、初期的な酸化膜の絶縁性能が高いだけでなく、素子特性の経時変動（信頼性悪化）要因となって問題とされる酸化膜の膜中電荷量についても、極めて低い程度にまで低減され、ＨＴＯ酸化膜と同等の性能を有するまでに改善される。
また、ＴＥＯＳ酸化膜の厚膜化を図る場合や、深いトレンチ構造にＴＥＯＳ酸化膜を埋め込む場合においても、酸化膜の膜質改善に有効な酸素がＴＥＯＳ酸化膜中へ均一に確実に熱拡散することが容易になるため、素子特性に悪影響を及ぼす可能性のある過度の高温または過剰な長時間の熱処理を行うことなく、安定なＴＥＯＳ酸化膜質へと改善することが可能となる。この結果、このように安定化された膜質を有するＴＥＯＳ酸化膜を半導体素子へ適用することにより、素子の高精度化を図ることが可能となり、信頼性の高い半導体装置を提供することが可能となる。 According to the present invention, after forming the TEOS oxide film formed by the CVD method, when the film thickness is increased beyond the film quality improvement effect by the heat treatment in the oxygen atmosphere, or from the film thickness that does not reach the film quality improvement effect. Even when an oxide film is buried in a deep trench structure, it is possible to provide a method for manufacturing a semiconductor device that improves the quality of the buried oxide film and improves element characteristics.
As described above, according to the TEOS oxide film forming method and the oxide film quality improving method according to the present invention, not only the initial insulation performance of the oxide film is high, but also the device characteristics change over time (reliability). Deterioration) The amount of charge in the oxide film, which is a problem, is also reduced to an extremely low level and improved to have the same performance as the HTO oxide film.
In addition, even when the thickness of the TEOS oxide film is increased or when the TEOS oxide film is embedded in a deep trench structure, oxygen effective for improving the quality of the oxide film can be uniformly and thermally diffused into the TEOS oxide film. Therefore, it becomes possible to improve the quality of the TEOS oxide film without performing an excessively high temperature or an excessively long heat treatment that may adversely affect device characteristics. As a result, by applying a TEOS oxide film having such a stabilized film quality to a semiconductor element, it is possible to increase the accuracy of the element and to provide a highly reliable semiconductor device. Become.

本発明の効果をさらに具体的に説明すると、第一に、減圧ＣＶＤ法により成膜されるＴＥＯＳ酸化膜は、比較的成膜温度が低いため、熱酸化膜やＨＴＯ酸化膜と比較して、膜中には多量の構造欠陥が含まれている。これらの構造欠陥は、主にＴＥＯＳ膜中に存在するシリコン原子の一部が酸素原子と化学量論的に結合せず、未結合手のまま存在していることに起因している。また、厚膜酸化膜中への酸素の拡散に対しては、比較的低温、短時間でも充分に均一熱拡散できる程度の厚さのＴＥＯＳ酸化膜に酸素を高濃度に含有する酸素含有層を隣接して積層させるようにしたので、ＴＥＯＳ酸化膜中の大部分のシリコン原子の未結合手が解消される結果、前記構造欠陥の修復が効果的に行われるのである。
本発明では、原料ガスとして、有機系のＴＥＯＳからなるソースガスを使用しているため、膜中には、炭化水素等の不純物や、ＯＨ基からなる構造水が含まれる。これらの不純物は容易に熱脱離するため、不活性雰囲気中で熱処理を行うことが熱処理の過程で膜中から排出させることとなり好ましい場合がある。 The effect of the present invention will be described more specifically. First, since the TEOS oxide film formed by the low pressure CVD method has a relatively low film formation temperature, compared with the thermal oxide film and the HTO oxide film, The film contains a large amount of structural defects. These structural defects are mainly attributed to the fact that some of the silicon atoms present in the TEOS film do not bond stoichiometrically with oxygen atoms and remain as dangling bonds. In addition, with respect to the diffusion of oxygen into the thick oxide film, an oxygen-containing layer containing a high concentration of oxygen is added to the TEOS oxide film having a thickness sufficient to allow uniform thermal diffusion at a relatively low temperature for a short time. Since the adjacent layers are laminated, the dangling bonds of most silicon atoms in the TEOS oxide film are eliminated, so that the structural defects are effectively repaired.
In the present invention, since a source gas made of organic TEOS is used as a source gas, the film contains impurities such as hydrocarbons and structural water made of OH groups. Since these impurities are easily thermally desorbed, it may be preferable to perform the heat treatment in an inert atmosphere because it is discharged from the film during the heat treatment.

以上述べた作用により、本発明によれば、酸化膜としての絶縁性能やエッチングレート等の基本特性の改善に加えて、素子特性の経時変動要因となりうる膜中電荷量についても、極めて低いレベルにまで低減することが可能であり、従来のＨＴＯ酸化膜の膜質と同等の安定化した酸化膜へ改善することが可能となるのである。
さらに、ＴＥＯＳ酸化膜の成膜工程と、酸素ガスにより、ＴＥＯＳ酸化膜の表面近傍に酸素を高濃度に含有する酸素含有層とを積層形成する工程を、所望の膜厚に達するまで複数回行い、その後、形成された積層膜に対し、所定の酸素拡散用熱処理を行うので、一回の成膜処理によるＴＥＯＳ酸化膜の膜厚を、酸素が均一に熱拡散させることが可能な程度に充分薄く設定しておけば、これら工程を複数回、所望の膜厚に達するまで繰り返し行うことにより、ＴＥＯＳ膜の厚膜化を図る場合においても、安定した膜質改善を図ることが可能となるのである。これに対し、従来のように一回の成膜工程でＴＥＯＳ酸化膜の厚膜化を図る場合でも高温で長時間の熱処理をすれば、ＴＥＯＳ酸化膜の膜質改善を図ることが可能ではあるが、微細化、高機能化された回路素子などへ悪影響を及ぼし、特性劣化や信頼性劣化を起こしやすくなる。 As described above, according to the present invention, in addition to the improvement of the basic characteristics such as the insulating performance and the etching rate as the oxide film, the amount of charge in the film that can be a factor of temporal variation of the element characteristics is also at a very low level. Thus, it is possible to improve the oxide film to a stabilized oxide film equivalent to the film quality of the conventional HTO oxide film.
Furthermore, the TEOS oxide film forming step and the step of forming an oxygen-containing layer containing oxygen in a high concentration near the surface of the TEOS oxide film by oxygen gas are performed a plurality of times until a desired film thickness is reached. Then, since the predetermined heat treatment for oxygen diffusion is performed on the formed laminated film, the film thickness of the TEOS oxide film by one film forming process is sufficiently high to allow oxygen to be thermally diffused uniformly. If the thickness is set thin, it is possible to improve the film quality stably even when increasing the thickness of the TEOS film by repeating these steps a plurality of times until reaching the desired film thickness. . On the other hand, even when the thickness of the TEOS oxide film is increased by a single film formation process as in the prior art, if the heat treatment is performed at a high temperature for a long time, the film quality of the TEOS oxide film can be improved. In other words, it adversely affects miniaturized and highly functional circuit elements and tends to cause deterioration of characteristics and reliability.

一方、例えば、０．５〜１．０μｍ以上の深さのトレンチ構造を有する溝内にＴＥＯＳ酸化膜を埋め込む工程を行う場合などのように、従来方法ではトレンチ深さ方向に対する深さ分だけ酸素を拡散させるに必要な過度な高温、過剰の長時間の熱処理が避けられないが、本発明によれば、トレンチ構造においても、安定した膜質改善を図ることが容易に可能となるのである。 On the other hand, in the conventional method, for example, when a TEOS oxide film is embedded in a groove having a trench structure having a depth of 0.5 to 1.0 μm or more, oxygen is increased by a depth corresponding to the trench depth direction. Although an excessively high temperature and an excessively long heat treatment necessary for diffusing the film are inevitable, according to the present invention, it is possible to easily improve the film quality stably even in the trench structure.

［実施例１］
以下、本発明の半導体装置に製造方法にかかる一実施例について、図面を用いて詳細に説明する。図１は本発明の半導体装置の製造方法にかかる実施例を示すプロセスシーケンス図を示す。図２は本発明にかかるＴＥＯＳ酸化膜成膜基板３の断面構造を示す。図３は本発明にかかる熱処理済ＴＥＯＳ酸化膜成膜基板４を示す断面図である。図４は本発明にかかるＴＥＯＳ酸化膜で埋設されたトレンチを有するＴＥＯＳ酸化膜成膜基板のトレンチ部分の断面図である。図１２は本発明にかかるＴＥＯＳ酸化膜形成に使用される真空処理装置を含む減圧ＣＶＤ装置の断面図である。
先ず、図１２に示す外部ヒーター機構５によって加熱された真空処理装置（ＣＶＤ装置）１内へボートにシリコン半導体基板１２を載置して導入し、真空処理装置１に接続された真空ポンプ６を使用して、真空処理装置１内を充分に真空排気する。この場合、外部ヒーター機構５による加熱温度は、ＴＥＯＳソースガスの分解、成膜に必要な温度であり、好ましくは、６００〜７５０℃の温度範囲が用いられる。ここでは説明の便宜上、真空処理装置部分をＣＶＤ装置と記したが、一般的にはこの真空処理装置に排気ポンプ、その他周辺部品一式を含めた全体を減圧ＣＶＤ装置と称する。 [Example 1]
Hereinafter, an embodiment according to a manufacturing method of a semiconductor device of the present invention will be described in detail with reference to the drawings. FIG. 1 is a process sequence diagram showing an embodiment according to a method of manufacturing a semiconductor device of the present invention. FIG. 2 shows a cross-sectional structure of a TEOS oxide film deposition substrate 3 according to the present invention. FIG. 3 is a sectional view showing the heat-treated TEOS oxide film formation substrate 4 according to the present invention. FIG. 4 is a cross-sectional view of a trench portion of a TEOS oxide film-formed substrate having a trench embedded with a TEOS oxide film according to the present invention. FIG. 12 is a sectional view of a low pressure CVD apparatus including a vacuum processing apparatus used for forming a TEOS oxide film according to the present invention.
First, a silicon semiconductor substrate 12 is placed on a boat and introduced into a vacuum processing apparatus (CVD apparatus) 1 heated by an external heater mechanism 5 shown in FIG. 12, and a vacuum pump 6 connected to the vacuum processing apparatus 1 is installed. In use, the inside of the vacuum processing apparatus 1 is sufficiently evacuated. In this case, the heating temperature by the external heater mechanism 5 is a temperature required for decomposition and film formation of the TEOS source gas, and a temperature range of 600 to 750 ° C. is preferably used. Here, for convenience of explanation, the vacuum processing apparatus portion is described as a CVD apparatus, but generally, the entire vacuum processing apparatus including an exhaust pump and a set of other peripheral components is referred to as a low pressure CVD apparatus.

この状態で、図１に示すプロセスシーケンスのａステップに従って、ＴＥＯＳガスを図１２に示す第一のガス導入管７から、例えば、２０ｓｃｃｍから５００ｓｃｃｍの範囲から適宜選択される流量で、所定の時間だけ真空処理装置１内に導入し、シリコン半導体基板２上に所定の膜厚だけＴＥＯＳ酸化膜８（図２）を成長させる。この時、後工程で形成されるＴＥＯＳ酸化膜に比べ高濃度の酸素を含有する酸素含有層１０（図２）から酸素が、やはり後工程の熱処理によって前記ＴＥＯＳ酸化膜８中へ均一に充分に熱拡散するためには、ＴＥＯＳ酸化膜８の成長をある膜厚以下にとどめる必要がある。例えば、熱処理温度８００〜１０００℃といった熱処理条件で、ＴＥＯＳ酸化膜８中へ充分酸素を熱拡散することが可能なＴＥＯＳ酸化膜８厚は２００ｎｍ以下であるが、１回で成長させるＴＥＯＳ酸化膜厚を極端に薄くしすぎるとと、所望の膜厚を成長させるための成膜回数が増加し、スループットの低下をまねくことから、１回で成長させる膜厚としては、５０〜２００ｎｍの範囲で、なるべく厚い方が好ましい。 In this state, according to step a of the process sequence shown in FIG. 1, the TEOS gas is supplied from the first gas introduction pipe 7 shown in FIG. 12 at a flow rate appropriately selected from the range of, for example, 20 sccm to 500 sccm, for a predetermined time. The TEOS oxide film 8 (FIG. 2) is grown on the silicon semiconductor substrate 2 by a predetermined thickness after being introduced into the vacuum processing apparatus 1. At this time, oxygen from the oxygen-containing layer 10 (FIG. 2) containing a higher concentration of oxygen than the TEOS oxide film formed in the subsequent process is sufficiently and uniformly introduced into the TEOS oxide film 8 by the heat treatment in the subsequent process. In order to perform thermal diffusion, it is necessary to keep the growth of the TEOS oxide film 8 below a certain film thickness. For example, the thickness of the TEOS oxide film 8 capable of sufficiently thermally diffusing oxygen into the TEOS oxide film 8 under a heat treatment condition of a heat treatment temperature of 800 to 1000 ° C. is 200 nm or less, but the TEOS oxide film thickness grown at one time. If the film thickness is excessively reduced, the number of film formations for growing a desired film thickness increases, leading to a decrease in throughput. Therefore, the film thickness grown at one time is in the range of 50 to 200 nm. The thicker one is preferable.

続いて、図１２の真空処理装置１に接続された真空ポンプ６を使用して、前述と同様な手段により、真空処理装置１内の残留ＴＥＯＳガスを十分に真空排気する。あるいは、残留するＴＥＯＳガスを真空排気した後、窒素等の不活性ガスを真空処理装置内に導入し、再度、真空排気することによって、ＴＥＯＳ残留ガスの低減効果をより高めるようにしてもよい。
次に、酸素ガスを図１２に示す第二のガス導入管９から、図１に示すシーケンスのｂステップに従って、例えば、０．１ｓｌｍから４０ｓｌｍの適宜選択される流量で、所定の時間だけ真空処理装置１内に導入し、高濃度の酸素を含有する酸素含有層１０（図２）を形成する。
続いて、ＴＥＯＳ酸化膜成膜工程と、酸素含有層の形成工程を、所望の酸化膜厚さが得られるまで複数回（図１のａ、ｂ、ｃ、ｄ、ｅ・・・・ステップ）適宜繰り返し行うことにより、図２に示すＴＥＯＳ酸化膜と酸素含有層との両層が交互に積層されたＴＥＯＳ酸化膜成膜基板３を形成する。 Subsequently, by using the vacuum pump 6 connected to the vacuum processing apparatus 1 of FIG. 12, the residual TEOS gas in the vacuum processing apparatus 1 is sufficiently evacuated by the same means as described above. Alternatively, after the residual TEOS gas is evacuated, an inert gas such as nitrogen is introduced into the vacuum processing apparatus, and the evacuation is performed again, thereby further enhancing the TEOS residual gas reduction effect.
Next, the oxygen gas is vacuum-treated for a predetermined time from the second gas introduction pipe 9 shown in FIG. 12 at a flow rate appropriately selected from 0.1 slm to 40 slm, for example, according to step b of the sequence shown in FIG. The oxygen-containing layer 10 (FIG. 2) containing high concentration of oxygen is introduced into the apparatus 1.
Subsequently, the TEOS oxide film forming step and the oxygen-containing layer forming step are performed a plurality of times until a desired oxide film thickness is obtained (steps a, b, c, d, e... In FIG. 1). By repeating appropriately, the TEOS oxide film forming substrate 3 in which both the TEOS oxide film and the oxygen-containing layer shown in FIG. 2 are alternately stacked is formed.

次に、例えば、同一真空処理装置１内にＴＥＯＳ酸化膜成膜基板３を留めたまま、図１のシーケンスのｆステップのように、ＴＥＯＳガスの排気後、所定の温度まで昇温し、所定の時間だけ加熱することで、酸素含有層１０から高濃度の酸素をＴＥＯＳ酸化膜層８へ拡散させ、図３に示す熱処理済ＴＥＯＳ酸化膜成膜基板４を形成する。図３では、符号１７は高濃度の酸素が拡散されて膜質が改善されたＴＥＯＳ膜を示し、符号１８は酸素が拡散されず、膜質が改善されていない残りのＴＥＯＳ膜部分を示す（符号１８の層厚は薄くてもよい）。符号１９は酸素が拡散される方向を示す。この時、熱処理雰囲気として、窒素、アルゴン、ヘリウム等の不活性ガスを用いるか、酸素ガス、もしくは不活性ガスと酸素の混合ガスを用いてもよく、熱処理温度としては、典型的には、８００℃から１０００℃の温度範囲が好ましい。 Next, for example, while the TEOS oxide film formation substrate 3 is kept in the same vacuum processing apparatus 1, the temperature is raised to a predetermined temperature after exhausting the TEOS gas as shown in step f of the sequence of FIG. 3 is diffused into the TEOS oxide film layer 8 to form the heat-treated TEOS oxide film-formed substrate 4 shown in FIG. In FIG. 3, reference numeral 17 denotes a TEOS film in which high-concentration oxygen is diffused to improve the film quality, and reference numeral 18 denotes a remaining TEOS film portion in which oxygen is not diffused and the film quality is not improved (reference numeral 18). May be thin). Reference numeral 19 indicates the direction in which oxygen is diffused. At this time, an inert gas such as nitrogen, argon or helium may be used as the heat treatment atmosphere, or oxygen gas or a mixed gas of inert gas and oxygen may be used. The heat treatment temperature is typically 800. A temperature range of from 1000C to 1000C is preferred.

最後に、真空処理装置１内を、真空ポンプ６を使用して真空排気し、真空処理装置１と真空ポンプ６の配管に介在する遮断バルブ１１により真空処理装置１と真空ポンプ６を遮断した状態で、真空処理装置１内に窒素等の不活性ガスを徐々に導入し、大気圧まで復帰させ、熱処理済半導体基板４を取り出す。
あるいは、前述したように、ＴＥＯＳ酸化膜成膜基板３を真空処理装置１から取り出し、その後、図示しない別の熱処理装置によって、所定の条件で酸素拡散のための熱処理を別途行ってもよい。
これらの結果、シリコン半導体基板２の上に、高濃度の酸素を含む酸素含有層１０が厚いＴＥＯＳ酸化膜８の間に複数層介在した積層状態で形成されたＴＥＯＳ酸化膜成膜基板３において、前記高濃度の酸素を含む酸素含有層１０から熱拡散により酸素がＴＥＯＳ酸化膜８中に供給されるため、ＴＥＯＳ酸化膜を厚膜化する必要がある場合においても、本発明にかかるようにＴＥＯＳ酸化膜の形成を所要の回数繰り返して積層にすれば、厚膜のＴＥＯＳ酸化膜でも確実に膜質改善を図ることができる。また、本発明によれば、例えば、膜厚の異なる厚いＴＥＯＳ膜を形成する場合であっても、１回当たり成膜するＴＥＯＳ酸化膜厚を固定しておくことが、酸素が熱拡散すべき膜厚は一定であるため、同一の熱処理条件で十分な膜質改善を図る上で、好ましい。 Finally, the inside of the vacuum processing apparatus 1 is evacuated using the vacuum pump 6, and the vacuum processing apparatus 1 and the vacuum pump 6 are shut off by the shutoff valve 11 interposed in the piping of the vacuum processing apparatus 1 and the vacuum pump 6. Then, an inert gas such as nitrogen is gradually introduced into the vacuum processing apparatus 1 to return to the atmospheric pressure, and the heat-treated semiconductor substrate 4 is taken out.
Alternatively, as described above, the TEOS oxide film formation substrate 3 may be taken out from the vacuum processing apparatus 1 and then separately subjected to heat treatment for oxygen diffusion under predetermined conditions by another heat treatment apparatus (not shown).
As a result, in the TEOS oxide film formation substrate 3 formed on the silicon semiconductor substrate 2 in a stacked state in which a plurality of oxygen-containing layers 10 containing high-concentration oxygen are interposed between the thick TEOS oxide films 8, Since oxygen is supplied into the TEOS oxide film 8 from the oxygen-containing layer 10 containing high-concentration oxygen by thermal diffusion, the TEOS oxide film can be formed even when it is necessary to increase the thickness of the TEOS oxide film. If the oxide film is repeatedly formed a required number of times to form a stacked layer, it is possible to reliably improve the film quality even with a thick TEOS oxide film. Further, according to the present invention, for example, even when a thick TEOS film having a different film thickness is formed, it is necessary to thermally diffuse oxygen by fixing the TEOS oxide film thickness to be formed once. Since the film thickness is constant, it is preferable for sufficiently improving the film quality under the same heat treatment conditions.

一方、深いトレンチ１３構造についても、図４に示すように、高濃度の酸素を含む酸化膜層１５が、溝内に成長させたＴＥＯＳ酸化膜層１６に沿って、深いトレンチ底部に至るまで複数層均一に積層形成すれば、所定の熱処理を行うことにより、酸素はＴＥＯＳ酸化膜１６中へ均一に熱拡散し、トレンチ構造１３内に埋め込んだＴＥＯＳ酸化膜であっても、確実に膜質改善を図ることができる。従って、本発明によれば、トレンチ溝１３が非常に深い場合でも、前述した同一の熱処理条件を使用することで、同様の改善効果を得ることができ、過度の熱処理を行うことによる素子特性への悪影響を最小限にとどめることが可能となる。また、このように安定化された膜質を有するＴＥＯＳ酸化膜を半導体素子へ適用することにより、素子の高精度化、高微細化を図ることが可能となり、かつ信頼性の高い半導体装置を提供することが可能となる。 On the other hand, also in the deep trench 13 structure, as shown in FIG. 4, a plurality of oxide film layers 15 containing high-concentration oxygen extend to the deep trench bottom along the TEOS oxide film layer 16 grown in the trench. If the layers are formed uniformly, oxygen is uniformly diffused into the TEOS oxide film 16 by performing a predetermined heat treatment, and even if the TEOS oxide film is buried in the trench structure 13, the film quality is surely improved. Can be planned. Therefore, according to the present invention, even when the trench groove 13 is very deep, the same improvement effect can be obtained by using the same heat treatment conditions described above, and the device characteristics can be obtained by performing excessive heat treatment. It is possible to minimize the adverse effects of In addition, by applying a TEOS oxide film having such a stabilized film quality to a semiconductor element, it is possible to increase the accuracy and miniaturization of the element and provide a highly reliable semiconductor device. It becomes possible.

本発明の半導体装置の製造方法にかかる一実施例のプロセスシーケンス図である。It is a process sequence diagram of one Example concerning the manufacturing method of the semiconductor device of this invention. 本発明の半導体装置の製造方法にかかる一実施例におけるＴＥＯＳ酸化膜成膜基板の要部断面図である。It is principal part sectional drawing of the TEOS oxide film film-forming substrate in one Example concerning the manufacturing method of the semiconductor device of this invention. 本発明の半導体装置の製造方法にかかる一実施例における熱処理済ＴＥＯＳ酸化膜成膜基板の要部断面図である。It is principal part sectional drawing of the heat-treated TEOS oxide film film-forming substrate in one Example concerning the manufacturing method of the semiconductor device of this invention. 本発明の半導体装置の製造方法にかかるＴＥＯＳ酸化膜で埋設されたトレンチ部分の断面図である。It is sectional drawing of the trench part embed | buried with the TEOS oxide film concerning the manufacturing method of the semiconductor device of this invention. 窒素雰囲気で熱処理を行ったＴＥＯＳ酸化膜成膜基板のＩ−Ｖ特性図である。It is an IV characteristic view of the TEOS oxide film formation substrate which heat-processed in nitrogen atmosphere. 酸素雰囲気で熱処理を行ったＴＥＯＳ酸化膜成膜基板のＩ−Ｖ特性図である。It is an IV characteristic view of the TEOS oxide film formation substrate which heat-processed in oxygen atmosphere. 窒素雰囲気で熱処理を行ったＴＥＯＳ酸化膜成膜基板のＣ−Ｖ特性図である。It is a CV characteristic figure of the TEOS oxide film film-forming substrate which heat-processed in nitrogen atmosphere. 酸素雰囲気で熱処理を行ったＴＥＯＳ酸化膜成膜基板のＣ−Ｖ特性図である。It is a CV characteristic figure of the TEOS oxide film film-forming substrate which heat-processed in oxygen atmosphere. 従来のＨＴＯ酸化膜成膜基板のＩ−Ｖ特性図である。It is an IV characteristic view of a conventional HTO oxide film deposition substrate. 従来のＨＴＯ酸化膜成膜基板のＣ−Ｖ特性図である。It is a CV characteristic view of a conventional HTO oxide film deposition substrate. 従来の半導体装置の製造方法にかかるＴＥＯＳ酸化膜を埋設したトレンチ構造における酸素の熱拡散を示すトレンチ部分断面図である。It is a trench partial sectional view showing thermal diffusion of oxygen in a trench structure in which a TEOS oxide film according to a conventional method for manufacturing a semiconductor device is embedded. 本発明の半導体装置の製造方法にかかる真空処理装置（ＣＶＤ装置）の断面図である。It is sectional drawing of the vacuum processing apparatus (CVD apparatus) concerning the manufacturing method of the semiconductor device of this invention.

Explanation of symbols

１真空処理装置（減圧ＣＶＤ装置）、
２シリコン半導体基板、
３ＴＥＯＳ酸化膜成膜基板、
４熱処理済ＴＥＯＳ酸化膜成膜基板、
５外部ヒーター機構、
６真空ポンプ、
７第一のガス導入管、
８、１６ＴＥＯＳ酸化膜、
９第二のガス導入管、
１０、１５酸素含有層、
１１遮断バルブ、
１３トレンチ、
１７酸素熱拡散済ＴＥＯＳ膜領域、
１８酸素未熱拡散ＴＥＯＳ膜領域、
１９熱拡散による酸素の動き。 1 vacuum processing equipment (low pressure CVD equipment),
2 silicon semiconductor substrate,
3 TEOS oxide film deposition substrate,
4 Heat-treated TEOS oxide film deposition substrate,
5 External heater mechanism,
6 Vacuum pump,
7 First gas introduction pipe,
8, 16 TEOS oxide film,
9 Second gas introduction pipe,
10, 15 oxygen-containing layer,
11 Shut-off valve,
13 trench,
17 oxygen thermal diffused TEOS film region,
18 Oxygen unheated diffusion TEOS film region,
19 Movement of oxygen by thermal diffusion.

Claims

A film forming step of depositing and forming a TEOS oxide film by a chemical vapor deposition method (CVD method) using TEOS (Tetra Ethyl Ortho Silicate) gas, and after exhausting the TEOS gas, supplying an oxygen gas and supplying the TEOS oxide film An oxygen diffusion heat treatment step for thermally diffusing oxygen in the TEOS oxide film by heating after repeating an oxygen-containing layer forming step in which the oxygen concentration of the TEOS oxide film is increased a plurality of times on the upper portion; A method of manufacturing a semiconductor device.

The method of manufacturing a semiconductor device according to claim 1, wherein the film thickness at one time in the film forming step is 50 to 200 nm.

3. The method of manufacturing a semiconductor device according to claim 1, wherein the film forming step and the oxygen-containing layer forming step are performed continuously in the same vacuum processing apparatus.

4. The method of manufacturing a semiconductor device according to claim 3, wherein the film forming step, the oxygen-containing layer forming step, and the oxygen diffusion heat treatment step are continuously performed in the same vacuum processing apparatus. .

5. The method of manufacturing a semiconductor device according to claim 1, wherein a film forming temperature range of the film forming step is 600 ° C. to 750 ° C. 6.

6. The method of manufacturing a semiconductor device according to claim 1, wherein a pressure range of the film forming process is 0.1 Torr (1 Torr = 133.3 Pa) to 3 Torr.

The method for manufacturing a semiconductor device according to claim 1, wherein the oxygen-containing layer forming step supplies oxygen gas in a flow rate range of 0.1 slm to 40 slm.

The method for manufacturing a semiconductor device according to claim 1, wherein a temperature range of the heat treatment step for oxygen diffusion is 800 ° C. to 1000 ° C. 8.

The method for manufacturing a semiconductor device according to claim 1, wherein the oxygen diffusion heat treatment step is performed in an inert gas-containing atmosphere.

9. The method of manufacturing a semiconductor device according to claim 1, wherein the heat treatment step for oxygen diffusion is performed in an oxygen atmosphere.

9. The method of manufacturing a semiconductor device according to claim 1, wherein the oxygen diffusion heat treatment step is performed in a mixed atmosphere of an inert gas and oxygen.