JPS58210843A - Vapor deposition device - Google Patents

Abstract

PURPOSE:To prevent the entry of impurities in a vapor deposition layer and the generation of crystal defects in the stage of forming the vapor deposition layer on a substrate moving in a reaction vessel, by holding a heating base and a conveyance base for the substrate without contacting with the inside wall of the vessel. CONSTITUTION:An Si wafer 2 is set on a heating base 3 and is introduced together with a conveyance base 4 through an inlet 12 into a reaction vessel 1. The wafer 2 is first heated gradually in a preheating chamber 7 and when the prescribed temp. is attained, the wafer is fed into a reaction chamber 8 where gaseous H2 and SiCl4 are supplied and an epitaxially gown layer of an Si single crystal is formed on the surface of the wafer 2. The substrate 2, the heating base 3 and the base 4 in the chamber 8 are moved by a driving device 5 provided on the outside without contacting with the inside wall of the vessel 1. If the table 4 is made of non-metals, the generation of crystal defects by the impurities intruded from the outside and the contamination of the reaction atmosphere that may result from the corrosion of the base 4 by working gases are obviated.

Description

【発明の詳細な説明】 本発明は気相成長装置に係シ、更に詳しくは基体を反応
容器内に収納し、高温に加熱しつつ原料ガスを供給し、
該基体上に気相成長層を形成し取シ出す一連の操作を連
続的に行なわしめる装置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vapor phase growth apparatus, and more specifically, a substrate is housed in a reaction vessel, and a source gas is supplied while heating it to a high temperature.
The present invention relates to an apparatus that continuously performs a series of operations for forming and removing a vapor-phase growth layer on the substrate.

反応容器内に基体を収納し、高温に加熱しなから原料ガ
スを導入することによって基体上に気相成長層を形成す
る気相成長方法は、特にＬＳＩ製造プロセス等半導体工
業の分野において広く通用されている。、気相成長方法
で形成される成長層としては例えば、シリコン酸化膜（
ｓｉｏｘ）、窒化シリコン膜（ＳｉＮ４）、多結晶シリ
コン膜（８ｉ）、リンガラス（ＰＥＧ）、酸素ドープ多
結晶シリコン膜、単結晶シリコン（Ｓｌ）などがある。The vapor phase growth method, in which a vapor phase growth layer is formed on the substrate by storing the substrate in a reaction vessel and heating it to a high temperature before introducing raw material gas, is widely used in the field of semiconductor industry, especially in LSI manufacturing processes. has been done. For example, a silicon oxide film (
siox), silicon nitride film (SiN4), polycrystalline silicon film (8i), phosphorous glass (PEG), oxygen-doped polycrystalline silicon film, single crystal silicon (Sl), etc.

このような気相成長層は一般に、可燃性、腐蝕性及び毒
性ガスを原料とすること、４００Ｃ〜１２００Ｃの高温
度に加熱する会費があること、形成する薄膜に均一性が
要求されることなどの理由から通常、基体を一定数反応
容器内に収納し処理するパッチ方式によって形成されて
いる。しかしながら、バッチ方式には４バツチの処理能
力に限度があシ、またスループットにも難点があること
からコスト低減の防げとなっている。この様な問題を解
消する方策の一つとして、基体を減圧状態に保つ仁とに
よって均一性を向上し、且つ処理数を増やす減圧気相成
長方法などの新たなバッチ方式が考案され、８１０．、
多結晶シリコン、単結晶７リコンの形成に利用されつつ
ある。しかしながら、近年、ＬＳＩ生産の増大し、更に
、コスト低減と歩留シ向上を目的とする基体直径の大口
径化（φ１２５〜１５０ｍ）の傾向にあるが、前述の減
圧方式の気相成長によっても均一性向上の点で対応が困
難となυつつある。Such a vapor-phase growth layer generally uses flammable, corrosive, and toxic gases as raw materials, requires a fee for heating to a high temperature of 400C to 1200C, and requires uniformity in the thin film formed. For these reasons, it is usually formed by a patch method in which a fixed number of substrates are housed in a reaction vessel and processed. However, the batch method has a limited processing capacity for four batches, and also has difficulties in throughput, which prevents cost reduction. As one of the measures to solve these problems, new batch methods have been devised, such as a reduced pressure vapor phase growth method, which improves uniformity by keeping the substrate under reduced pressure and increases the number of treatments. ,
It is being used to form polycrystalline silicon and single crystal 7 silicon. However, in recent years, with the increase in LSI production, there is a trend toward larger substrate diameters (φ125 to 150 m) for the purpose of reducing costs and improving yields. It is becoming difficult to deal with this problem in terms of improving uniformity.

以上説明したバッチシステスの欠点を解消する方法とし
て第１図に示すような、加熱台３に載置した基体２を一
方から連続的に反応容′＃１内に供給しつつ気相成長を
行なわしめ、他方から連続的に取シ出す、いわゆる連続
搬送方式がある。この方法は生産が連続的に行なわれる
点から生産性に看れ、また、基体を一枚ずつ処理するこ
とから基体全面の均一性を保つことはバッチ方式に比べ
て容易である。しかしながら、一般に気相成長層には■
不純物の混入、■結晶欠陥、■異物やフレークなどによ
る異常成長等が存在すると製品歩Ｗりを悪くするなどの
理由から、連続方式において最も重要な基体の搬送手段
の適切な方法が開発されていない。即ち、搬送台に金属
材料を用いることは、反応が高温で且つ比較的腐蝕性ガ
スを原料とするため不純物の混入や結晶欠陥発生の要因
となる。また、第１図に示すような車輪等を用い反応容
器内に接触しながら搬送する方法は、反応析出物は容器
内壁へも付着することからダストを舞い上らせ結晶欠陥
の発生や突起等の異常成長の原因となる。以上のよう彦
点から、連続搬送方式の気相成長装置の実用化は遅れて
いる。As a method for solving the above-described drawbacks of the batch system, as shown in FIG. There is a so-called continuous conveyance system in which one is taken out continuously from the other. This method has high productivity because production is carried out continuously, and since the substrates are processed one by one, it is easier to maintain uniformity over the entire surface of the substrate than in the batch method. However, in general, the vapor phase growth layer has ■
For reasons such as contamination of impurities, ■crystal defects, and ■abnormal growth due to foreign matter or flakes, etc., which impair product yield, an appropriate method for conveying the substrate, which is the most important method in continuous systems, has not been developed. do not have. That is, when a metal material is used for the conveyance table, the reaction takes place at a high temperature and relatively corrosive gas is used as a raw material, which causes the contamination of impurities and the generation of crystal defects. In addition, the method of conveying while contacting the inside of the reaction vessel using wheels, etc. as shown in Figure 1, causes the reaction precipitates to adhere to the inner wall of the vessel, causing dust to be thrown up, causing crystal defects and protrusions. It causes abnormal growth of. As described above, the practical application of continuous conveyance type vapor phase growth equipment has been delayed since the Hiko point.

特に、反応温度が１０００ｔ：’以上、原料ガスとして
腐蝕性ガスを使用し、高純度で且つ結晶欠陥のない気相
成長層の形成が要求されるシリコンのエピタキシャル成
長への連続搬送方式の採用は非常に困難となっている。In particular, it is extremely difficult to adopt a continuous transport method for epitaxial growth of silicon, where the reaction temperature is 1000 t:' or higher, a corrosive gas is used as the raw material gas, and the formation of a vapor-phase growth layer with high purity and no crystal defects is required. It has become difficult.

本発明の目的は従来の連続搬送方式気相成長装置の欠点
を解消し、成長ノー中にの不純物の混入、結晶欠陥の導
入を無くシ、且ら異常成長等の発生も生じない連続搬送
方式の気相成長装置を提供するにある。The purpose of the present invention is to eliminate the drawbacks of conventional continuous conveyance type vapor phase growth equipment, to eliminate the introduction of impurities into the growth layer and crystal defects, and to provide a continuous conveyance type that does not cause abnormal growth. The company provides vapor phase growth equipment.

本発明の特徴とするところは気相成長の反応容器内にお
いて、基体及び基体搬送台と容器内壁を非接触状態に保
ち気相成長するにある。更に他の特徴とする所は搬送台
材質に非金属材料を用い実質的に不純物汚染の無い状況
下において気相成長するにある。更にまた、他の特徴と
するところは反応領域の圧力を基体搬送台駆動機構を含
む領域に比べ高くすることを特徴とするにある。The feature of the present invention is that in a reaction vessel for vapor phase growth, the substrate and the substrate carrier are kept in a non-contact state with the inner wall of the vessel during vapor phase growth. Another feature is that a non-metallic material is used as the carrier material and vapor phase growth is performed under conditions substantially free from impurity contamination. Furthermore, another feature is that the pressure in the reaction region is higher than that in the region including the substrate transport platform drive mechanism.

以下本発明を第２図に従って説明する。第２図はシリコ
ンのエピタキシャル成長に本発明を適用する場合の断面
説明図である。１は石英ガラス製の反応容器、２は基体
のシリコンウェハ、３はカン 一ン丘ｓｔｃをコーティングした基体加熱台、４は例え
ば材質として石英板等の非金属材を用いた基体搬送台、
５は基体搬送台４の駆動装置である。The present invention will be explained below with reference to FIG. FIG. 2 is an explanatory cross-sectional view when the present invention is applied to epitaxial growth of silicon. 1 is a reaction vessel made of quartz glass, 2 is a silicon wafer as a substrate, 3 is a substrate heating table coated with a cantilever STC, 4 is a substrate transfer table made of a non-metallic material such as a quartz plate,
Reference numeral 5 denotes a drive device for the substrate transport platform 4.

また、反応容器内は、Ｎ１のエアカーテンで外気の混入
を防ぐためのアイソレータ６、Ｎ、置換しつつ予熱する
予熱室７、キャリヤガスのＨ！とＳｉ原料ガス（例えば
５ＩＨ４，５ＩＣ１等）を導入し１１００〜１２５０Ｇ
の高温度でＳｔ単結晶層を形成する反応室８、Ｎ、置換
しながら基体を冷却する降温室９、史に反応室へのＮ、
ガスの混入を防ぐアイソレータ１０に分割されている。Inside the reaction vessel, there is an isolator 6 for preventing outside air from entering with an N1 air curtain, a preheating chamber 7 for preheating while replacing N air, and a carrier gas H! and Si raw material gas (e.g. 5IH4, 5IC1, etc.) is introduced to 1100~1250G
A reaction chamber 8 in which a St single crystal layer is formed at a high temperature of
It is divided into isolators 10 that prevent gas from entering.

１１は加熱装置である。シリコンクエバ２を加熱台３０
所定位置にセットする。加熱台３は搬送台４が駆゛動装
置５によって図中矢印方向に移動しているため、ウェハ
２は入口１２よ＃）Ｎ、エアーカーテンをくぐジノ１１
次反応容器１内に送ル込まれる。ウェハ２は予熱室７で
徐々に昇温され、所定温度（約１１５０ｔ：’）に達し
た時反応室８に送られる。区応菟８にはＨ，ガスと共に
例えばｆ３ｉＣ１４ガスが供給されているため次式 ％式％： により基体２のクリコンウェハ２上に単結晶３ｔのエピ
タキシャル成颯層が形成される。この場合、析出シリコ
ンの一部は反応容器ｌ内壁、加熱台３、搬送台４にも付
着する。反応室８において基体２及び加熱台３、搬送台
４は第２図（ａ）及び（ｂ）に示すように反応容器１の
内壁と接することなくこと必ら、本発明の装置によれば
基体表面外に析、フｆｉ、４ 出したＳｉの飛散による成長層の汚染は起シ得な′い。11 is a heating device. Silicon Cueva 2 on heating stand 30
Set it in place. Since the heating table 3 is moved in the direction of the arrow in the figure by the driving device 5, the wafer 2 is transferred to the inlet 11 through the air curtain.
Next, it is sent into the reaction vessel 1. The wafer 2 is gradually heated in the preheating chamber 7, and when it reaches a predetermined temperature (approximately 1150 t:'), it is sent to the reaction chamber 8. Since, for example, f3iC14 gas is supplied to the gas supply 8 along with H and gas, an epitaxial layer of single crystal 3t is formed on the crystalline wafer 2 of the base body 2 according to the following formula. In this case, a portion of the deposited silicon also adheres to the inner wall of the reaction vessel 1, the heating table 3, and the transport table 4. In the reaction chamber 8, the substrate 2, the heating table 3, and the transfer table 4 are not in contact with the inner wall of the reaction vessel 1, as shown in FIGS. 2(a) and 2(b). There is no possibility of contamination of the grown layer due to scattering of Si precipitated outside the surface.

また、搬送台４には石英を用いていることから、高温、
腐蝕性の反応室内においても不純物発生の原因となるこ
とはない。気相成長を終えた基体２は降温室９を通加中
にＮ、ｌｔ換を受けながら徐々に冷却され、反応容器１
の出口１３側エアカーテンをくぐって容器外に搬出され
る。In addition, since the transport table 4 is made of quartz, high temperatures and
It does not cause the generation of impurities even in the corrosive reaction chamber. The substrate 2 that has undergone vapor phase growth is gradually cooled while undergoing nitrogen and lt exchange while passing through the cooling chamber 9.
It passes through the air curtain on the outlet 13 side and is carried out of the container.

第３図は本発明の装置を用いて連続的に気相成長を行な
う場合を示す。搬送台４を適切な長さに分割し、成長を
終え反応容器出口１３から搬出した搬送台４を再び人口
１２側に返し使用する。この場合、搬送台４が反応容器
内壁に接するのを防ぐため駆動装［５は搬送台４の端部
を狭むようになっている。FIG. 3 shows a case in which vapor phase growth is carried out continuously using the apparatus of the present invention. The carrier 4 is divided into appropriate lengths, and the carrier 4, which is carried out from the reaction container outlet 13 after the growth is finished, is returned to the population 12 side for use. In this case, in order to prevent the conveyance table 4 from coming into contact with the inner wall of the reaction vessel, the driving device [5 is designed to narrow the end portion of the conveyance table 4.

第４図は搬送台４自体の容器出口１３から人口１２への
移動操作を省略し、よシ合理的にした気相成長装置の説
明である。FIG. 4 is an explanation of a more streamlined vapor phase growth apparatus that omits the operation of moving the conveyor table 4 itself from the container outlet 13 to the container 12.

搬送台４はドーナツ状の形状となっていることから、駆
動装置５によシ回転運動を与えるのみで搬送台４を反応
容器出口１３から入口１２に送ることができる。Since the conveyance table 4 has a donut-like shape, the conveyance table 4 can be sent from the reaction container outlet 13 to the inlet 12 simply by applying rotational motion to the drive device 5.

以上の実施例の説明において、搬送台駆動装置５は反応
容器１外に設置する場合について説明したが、ガスが不
活性で且つ比較的低温領域である予熱室７、降温室９の
一部、容器出入口のアイソレータ６部に設置しても実質
的に有効であることは当然である。In the above description of the embodiment, a case has been described in which the carrier driving device 5 is installed outside the reaction vessel 1. It goes without saying that it is substantially effective even if it is installed at the isolator 6 section at the entrance and exit of the container.

また、本実施例においては搬送台４の材質として石英を
選んだが、高温ないし腐蝕性ガス雰囲気中で実質的に不
純物汚染のない材質を別に選ぶことは可能である。Ｓｉ
のエピタキシャル成長の様に高温（１１５０Ｃ）で腐蝕
性のガスを使用する場合には多結晶シリコン材、ＳＩＣ
被１したカーボン材等が望ましい。５ｔｃａ［カーボン
は加熱台として通常用いられることから搬送台と加熱台
の一体化も可能である。Further, in this embodiment, quartz is selected as the material for the conveyor table 4, but it is possible to select another material that is substantially free from impurity contamination in high temperature or corrosive gas atmospheres. Si
When using corrosive gas at high temperatures (1150C), such as epitaxial growth, polycrystalline silicon material, SIC
A coated carbon material or the like is preferable. 5tca [Since carbon is usually used as a heating table, it is also possible to integrate the conveying table and the heating table.

第５図は反応容器１内を支切シ板１４により区切シ、２
室構造とし、加熱台３及びその上に載１ｗした基体（図
中省略）は石英製搬送台４によシ支えることによって、
実質的な反応領域比Ｓにおいて内壁と非接触状態となる
ようにしている。第６図は断面構造説明図である。搬送
台４の駆動は容器下段室ＵＲに収納された駆動機構（無
限ベルト）５に固定され矢印方向に移動する。容器下段
室ＵＲは水冷構造のステンレス材で作成されているため
ステンレス製無限ベルト５が接しながら移動しても何ら
問題を生じない。更に重要な点は、反応領域比Ｓの圧力
は容器下段室ＵＲに比べ常に高く保られることである。FIG.
The heating table 3 and the substrate (not shown in the figure) placed on the heating table 3 are supported by a quartz transport table 4.
It is made to be in a non-contact state with the inner wall at a substantial reaction area ratio S. FIG. 6 is an explanatory diagram of the cross-sectional structure. The transport table 4 is driven by a drive mechanism (endless belt) 5 housed in the container lower chamber UR, and moves in the direction of the arrow. Since the container lower chamber UR is made of a water-cooled stainless steel material, no problem will occur even if the stainless steel endless belt 5 moves while touching it. A further important point is that the pressure in the reaction zone ratio S is always kept higher than in the lower chamber UR of the container.

即ち、原料ガスは反応領域几Ｓ側から導入され、容器下
段室ＵＲに設けられた排出口（図中略］から排気される
ため反応領域几Ｓ内には駆動によシ生ずるダクト、更に
金属製駆動装置５に接し汚染された排ガスの廻シ込みは
防がれる。この結果、基体上には欠陥のない良質の気相
成長層を形成することができる。That is, the raw material gas is introduced from the reaction area S side and exhausted from the exhaust port (not shown) provided in the lower chamber UR of the container. Contaminated exhaust gas is prevented from entering the drive device 5. As a result, a defect-free, high-quality vapor phase growth layer can be formed on the substrate.

第７図は反応容器ｌ内を２室に支切る別な方法を示した
ものである。支切シ板４を容器中央に投錯 け、搬送台４を側壁に治って反応室１１に立ち上げた場
合を示すがその効果は第５，６図と同様である。FIG. 7 shows another method of dividing the interior of the reaction vessel 1 into two chambers. A case is shown in which the dividing plate 4 is placed in the center of the container and the transfer table 4 is placed on the side wall to stand up in the reaction chamber 11, but the effect is the same as in FIGS. 5 and 6.

本発明によれば気相成長層の不純物汚染、異常成長を大
幅に低減できる、本装置を用い、１００叫φシリコンウ
ニ・・にエピタキシャル成長ｔ＊゛を形成した結果、多
結晶状突起欠陥数は約２ケ／つ°エバ、不眺物汚染と対
応する成長層キャリヤライフタイムは約９０μｓでアシ
、これらの値は従来のバッチ方式によシ形成したエピタ
キシャル層とｔｌは同等である。According to the present invention, impurity contamination and abnormal growth of the vapor-grown layer can be significantly reduced.As a result of forming epitaxial growth t*' on a 100-diameter silicon sea urchin using this apparatus, the number of polycrystalline protrusion defects was reduced. The carrier lifetime of the grown layer corresponding to the unsightly contamination is about 90 μs, and these values are equivalent to the tl of the epitaxial layer formed by the conventional batch method.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は従来の気相成長装置を説明する図、第２図は本
発明装置の一実施例を示す図で、（ａ）は縦断面図、（
ｂ）は（ａ）のＡ−Ａｔ７Ｊ断線での横断面図、第３図
〜第５図はそれぞれ本発明の他の実施例を示す図、第６
図は第５図の実施例の横断面図、第７図は第６図の変型
例を示す図である。 ｌ・・・反応容器、２・・・基体、３・・・加熱台、４
・・・搬送め　１　口 察２の 第３０ 窮４（２） 惑ζ幻 ｌりＬ　　口FIG. 1 is a diagram illustrating a conventional vapor phase growth apparatus, and FIG. 2 is a diagram showing an embodiment of the apparatus of the present invention, in which (a) is a longitudinal cross-sectional view;
b) is a cross-sectional view taken along the line A-At7J in (a), FIGS. 3 to 5 are views showing other embodiments of the present invention, and FIG.
This figure is a cross-sectional view of the embodiment of FIG. 5, and FIG. 7 is a diagram showing a modification of FIG. 6. l...Reaction container, 2...Substrate, 3...Heating stand, 4
...transportation 1. 30th point of 2. 4 (2) Confusion ζ illusion L mouth

Claims (1)

【特許請求の範囲】 １、基体を加熱台上に載置し、該基体と加熱台を搬送台
を用いて反応容器の一方から該容器内に導入し、該容器
内に原料ガスを供給し、該基体を加熱装置によシ加熱し
つつ該基体上に気相成長層を形成し、反応容器の他方か
ら該基体を連続的に取シ出す気相成長装置において、反
応領域の外部に搬送台の駆動機構を設けることによシ前
記基体、加熱台及び−搬送台は、少なくとも反応領域に
おいて容器内壁と非接触状態を保つことを特徴とする気
相成長装置。 λ　前記ｉ＠１項の気相成長装置において、実質的反応
領域の圧力を搬送台送シ機構を含む領域に比べて高くし
たことを特徴とする気相成長装置。 ３、前記第１．２項の搬送台材質として非金属材料を使
用することを特徴とする気相成長装置。[Claims] 1. A substrate is placed on a heating table, the substrate and the heating table are introduced into the reaction vessel from one side using a conveyance table, and a raw material gas is supplied into the vessel. , in a vapor phase growth apparatus in which a vapor phase growth layer is formed on the substrate while heating the substrate with a heating device, and the substrate is continuously taken out from the other side of the reaction vessel, the substrate is transported to the outside of the reaction region. A vapor phase growth apparatus characterized in that by providing a drive mechanism for the stage, the substrate, the heating stage, and the transport stage are maintained in a non-contact state with the inner wall of the container at least in the reaction region. [lambda] A vapor phase growth apparatus according to item i@1, characterized in that the pressure in the substantial reaction area is higher than in the area including the conveyance table feeding mechanism. 3. A vapor phase growth apparatus characterized in that a non-metallic material is used as the material of the conveyance table described in item 1.2 above.