JPS62128517A - Vapor growth method - Google Patents

Abstract

PURPOSE:To maintain a crystal having high quality with excellent uniformity extending over a large area, and to reduce the cost of a device manufacture by the growth crystal largely by depositing carbon on the back of a substrate, heating carbon through high-frequency induction and heating the substrate by heat from heated carbon. CONSTITUTION:A substrate 13, on the back thereof carbon 21 in thickness of 300mum is deposited through a CVD method, is positioned on a susceptor 20 made of quartz placed with a slight angle. Carbon 21 is heated through high-frequency induction, and the substrate 13 is heated by heat from carbon 21. There is no clearance between the substrate and carbon as a heating body, thus uniformly heating the substrate even under decompression.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は化合物半導体等を基板上に結晶成長す。[Detailed description of the invention] Industrial applications The present invention grows crystals of compound semiconductors and the like on a substrate.

る場合に用いられる気相成長方法に関するものである。The present invention relates to a vapor phase growth method used when

従来の技術 近年、■−■族および■−■族等化合物および混晶半導
体の気相エピタキシャル成長法、特に有機金属気相成長
法（Ｍ　ＯＯＶ　Ｄ　：　Ｍｅｔａｌ　Ｄｒｇａｎｉｃ
Ｃｈｅｍｉｃａｌ　Ｖａｐｏｒ　Ｄｅｐｏｓｉｔｉｏｎ
法）が、大面積にわたる均一性、量産性、膜厚や組成の
制御性等の点から注目を集め、各所で研究開発が活発に
行なわれている。Background Art In recent years, vapor phase epitaxial growth methods for ■-■ group and ■-■ group compounds and mixed crystal semiconductors, particularly metal organic vapor phase epitaxy (MOOVD), have been developed.
Chemical Vapor Deposition
(method) has attracted attention due to its uniformity over a large area, mass productivity, and controllability of film thickness and composition, and research and development is being actively conducted in various places.

一般に、この種の気相成長法に用いられる装置は、結晶
成長室内の気体の圧力によって、常圧（大気＋１）ＭＯ
ＣＶＤ装置オヨヒ減１′ＥＭＯｃＶＤ装置に大別される
。常圧（大気圧）ＭＯＣＶＤ装置の方が、装置の構造が
簡単であり、原料ガスの切り変え等による結晶成長室内
の圧力変動も少ない。しかし、エピタキシャル成長する
材料によっては、結晶成長室内の圧力が大気圧よりも低
い方が好ましい場合がある。特にＺｎＰ系の場合顕著で
ある。Ｉｎの原料ガス材料である例えばトリエチルイン
ジウムＴ　Ｅ　Ｘ　（（Ｃ，、Ｈ５）、Ｉｎ″ｌは、低
温で分解し易く不安定であるために、サセプタからの熱
によって基板に達するまでに分解し、成長に全く寄与し
なくなる場合がある。そこで、ＴＥＩが結晶成長室内に
入るとすみやかに基板上に達するようにする方法として
減圧下でｒｎＰ系の結晶成長を行なう試みがなされてい
る。減圧下で行なう気相成長法では、ＴｌＣｌのガス分
子のモ均自由行程が長くでき、基板表面へすみやかに輸
送できる。Generally, the equipment used for this type of vapor phase growth method uses the pressure of the gas in the crystal growth chamber to produce MO at normal pressure (atmosphere + 1).
CVD equipment is broadly classified into 1'EMOcVD equipment. A normal pressure (atmospheric pressure) MOCVD apparatus has a simpler structure and less pressure fluctuations in the crystal growth chamber due to switching of raw material gas, etc. However, depending on the material to be epitaxially grown, it may be preferable for the pressure inside the crystal growth chamber to be lower than atmospheric pressure. This is particularly noticeable in the case of ZnP. For example, triethylindium TEX ((C,,H5), In''l, which is a raw material gas material for In, is unstable and easily decomposes at low temperatures, so it is decomposed by the heat from the susceptor before reaching the substrate. Therefore, attempts have been made to grow rnP-based crystals under reduced pressure as a way to ensure that TEI reaches the substrate quickly once it enters the crystal growth chamber. Under reduced pressure In the vapor phase growth method carried out, the homogeneous free path of TlCl gas molecules can be lengthened, and they can be quickly transported to the substrate surface.

第２図に減圧下で気相成長を行う際に用いられる代表的
な気相装置の構成を示す。同図中の１は有機Ｉｎ化合物
ＴＥＩ（）リエチルインジウム（０２Ｈ５）　５Ｉｎ　
）、２はＴＦＬＩの蒸気圧を制御するための恒温槽、３
は■族元素の水素化物ＰＨ，（ホスフィン）を各々示す
。結晶成長室６内の排気はロータリポンプ１０’ｉ５用
いて行なわれる。納品成長室ｅ内の圧力はゲートバルブ
９の開閉の度合いと制菌して行なう。ロータリボング１
０の排気ラインは原料ガスベントライン５と接続されて
有害物質除去用排ガス処理装置１１に導ひかれている。FIG. 2 shows the configuration of a typical vapor phase apparatus used for vapor phase growth under reduced pressure. 1 in the figure is an organic In compound TEI () ethyl indium (02H5) 5In
), 2 is a constant temperature bath for controlling the vapor pressure of TFLI, 3
represent the hydrides PH and (phosphine) of group (Ⅰ) elements, respectively. The inside of the crystal growth chamber 6 is evacuated using a rotary pump 10'i5. The pressure inside the delivery growth chamber e is controlled by controlling the degree of opening and closing of the gate valve 9. rotary bong 1
The exhaust line 0 is connected to a raw material gas vent line 5 and led to an exhaust gas treatment device 11 for removing harmful substances.

半導体基板１３はカーボン製サセプタ１２上に載置し、
高周波誘導によってカーボン製サセプタ１２を加熱して
その熱によって半導体基板１３を加熱するようになって
いた。The semiconductor substrate 13 is placed on the carbon susceptor 12,
The carbon susceptor 12 is heated by high frequency induction, and the semiconductor substrate 13 is heated by the heat.

発明が解決しようとする問題点 しかしながら上記の様な装置だと減圧下において、カー
ボン製サセプタ上に載置された半導体基板を均一に加熱
することは難しい。例えば基板裏面とサセプタ表面が密
着していないと均一加熱は難しいし、又、サセプタその
ものが不均一加熱されている場合がなく、ウェハーが２
インチ、３インチ　　と大きくなると基板の均一加熱は
非常に困難であった。Problems to be Solved by the Invention However, with the above-mentioned apparatus, it is difficult to uniformly heat a semiconductor substrate placed on a carbon susceptor under reduced pressure. For example, if the back surface of the substrate and the surface of the susceptor are not in close contact, uniform heating is difficult, and the susceptor itself is not heated unevenly, and the wafer is
It was very difficult to uniformly heat the substrate when the size was as large as 3 inches.

問題点を解決するだめの手段 本発明は、上記問題点を触決するため、基板裏面に炭素
を堆積し、高周波誘導により前記炭素を加熱し、加熱さ
れた炭素からの熱で前記基板全加熱して前記基板上に薄
膜全形成するものである。Means to Solve the Problems In order to solve the above problems, the present invention deposits carbon on the back surface of the substrate, heats the carbon by high frequency induction, and completely heats the substrate with the heat from the heated carbon. The thin film is entirely formed on the substrate.

作用 この技術的手段による作用は次のようになる。action The effect of this technical means is as follows.

すなわち、基板裏面に炭素全堆積し、高周波誘導により
前記炭素を加熱し、加熱された炭素からの熱で前記基板
を加熱するので、基板と加熱体炭素との間にすき間がな
い。したがって、減圧下においても基板？均一に加熱す
ることができる〇実施例 本発明の一実施例における気相成長方法を実施する気相
成長装置の具体的な一例を第１図に示−ち２０は少し角
度を付けた石英製サセプタて、２１は基板１３の裏面に
ＣＶＤ法により堆積された例えば厚み３００μｍの炭素
である。That is, since all of the carbon is deposited on the back surface of the substrate, the carbon is heated by high frequency induction, and the substrate is heated with the heat from the heated carbon, there is no gap between the substrate and the heating element carbon. Therefore, the substrate even under reduced pressure? Embodiment in which uniform heating is possible A specific example of a vapor phase growth apparatus for carrying out the vapor phase growth method according to an embodiment of the present invention is shown in FIG. The susceptor 21 is carbon with a thickness of, for example, 300 μm deposited on the back surface of the substrate 13 by the CVD method.

次に本発明の効果ケより明らかにするため、炭素が堆積
されたＸｎＰ基板上にＩｎＰ／ＩｎＧａＡｓＰ系多重童
子井戸栴造を作製し、膜厚９組成の均一性および界面の
急峻性を調べた。Next, in order to clarify the effects of the present invention, an InP/InGaAsP multi-dojido layer was fabricated on an XnP substrate on which carbon was deposited, and the uniformity of the film thickness (9) and the steepness of the interface were investigated. .

使用した■族原料有機金属はＴ　Ｘ　Ｉ　（トＩＪエチ
ルインジウム（０２Ｈ５）　、Ｉｎ）　’）、Ｔ　ＲＧ
　（）リエチルガリウム（Ｃ２Ｈ３）　、Ｇａ　’：ｌ
で、■族原料ガスはＰＨ３（ホスフィン）と、ＡｓＨ３
（アルシン）である。The organometallic group III raw materials used were T
() ethyl gallium (C2H3), Ga':l
So, the group III raw material gases are PH3 (phosphine) and AsH3.
(Arsine).

キャリアガスはＰｄ拡散Ｉｌ！Ｉを通った水素で６１３
７ｍ１ｎである。基板温度は、基板裏面から赤外線温度
計により測定し、６アＯ’Ｃである。結晶成長室内圧力
は１６０丁ｏｒｒである。’！’ＥＩ、ＴＥＧ。The carrier gas is Pd diffusion Il! 613 with hydrogen passing through I
It is 7m1n. The substrate temperature was measured from the back side of the substrate using an infrared thermometer and was 6 O'C. The pressure inside the crystal growth chamber is 160 C orr. '! 'EI, TEG.

ＰＨ３，ＡｓＨ，の流量はそれぞれ３５　ｃｃ／ｗｉｎ
　、　ｓ。Flow rate of PH3, AsH, each is 35 cc/win
, s.

ＰＨ３（ｉ７予め流す。上記流量で成長された結晶はＩ
ｎＰ基板に格子整合した（１Δａ／ａ　ｌ　（１ｏ　’
）Ｉｎ、、ＧａｘＡｓ、、Ｐ、−ｙ（ｘ　〜０．２７．
　　ｙ　〜Ｏ−５７）４元混晶が得られる。膜厚のばら
つきは数チ以内にあり、又、組成のバラツキはフォトル
ミから、１　ｎｍ以内にある。PH3 (i7 is flowed in advance. The crystal grown at the above flow rate is I
Lattice matched to nP substrate (1Δa/a l (1o'
)In,,GaxAs,,P,-y(x~0.27.
y ~O-57) A quaternary mixed crystal is obtained. The variation in film thickness is within a few inches, and the variation in composition is within 1 nm from photoluminescence.

次［Ｔ　Ｅ　Ｇ　トＡ、Ｈ５（Ｄ　Ｏｎ−０ｆ’ｆ’カ
ら、１００八ＩｎＰ　、　１００　Ａ　ＩｎＧａＡＳＰ
（７）　１１：）へ７からなる超格子を作成しＳ　ＩＭ
ＳでＩｎ、Ｇａ、Ａｓ、Ｐの厚さ方向の分布を分析した
。形成された積層構造で、いずれの元素もヘテロ界面に
おいて、遷移領域は１０八以下であり、界面の急峻性は
飛躍的に向上した。Next
(7) Create a superlattice consisting of 7 to 11:) and SIM
The distribution of In, Ga, As, and P in the thickness direction was analyzed using S. In the formed layered structure, the transition region of each element at the hetero interface was 108 or less, and the steepness of the interface was dramatically improved.

以上述べた実姐例において、ＩｎＰ　／ＩｎＧａＡｓＰ
系の結晶成長について説明したが、本発明による気相成
長方法は、ＡｌＧａＡｓ　／　ＧａＡｓ系、　ＡｌＧａ
工ｎＰ　／ＧａＡｓ系は勿論のこと、他のＩＩ　−Ｖ族
およびｎ−■族化合物半導体および混晶半導体の結晶成
長に用いることができる。さらに、以上述べた実悔例は
有機金属気相成長法の場合であったが、ハイドライド気
相エピタキシャル成長法やクロライド気相エピタキシャ
ル成長法等の他の気相成長法の場合にも適用できる。又
、化合物半導体の気相成長だけテナク、ＳｉＯ□ヤ８１
３Ｎ４等ノ各種Ｃ’１ＤｆＰ：にも用いることができる
のは言うまでもない。In the practical example described above, InP /InGaAsP
Although the crystal growth of the AlGaAs/GaAs system has been described, the vapor phase growth method according to the present invention can be applied to AlGaAs/GaAs systems, AlGaAs
It can be used for the crystal growth of not only the nP/GaAs system but also other II-V group and n-2 group compound semiconductors and mixed crystal semiconductors. Furthermore, although the above-mentioned example of regret was a case of metal-organic vapor phase epitaxy, it can also be applied to other vapor phase epitaxy methods such as hydride vapor phase epitaxial growth method and chloride vapor phase epitaxial growth method. In addition, Tenac, SiO
Needless to say, it can also be used for various C'1DfPs such as 3N4.

発明の効果 本発明の気相成長方法は、基板裏面に炭素を堆積し、均
一に基板を加熱するので、高品質の結晶が大面積にわた
って均一性よく保たれ、組成、不純物濃度のばらつきも
少なく、ヘテロ界面の遷移層は１０Å以下で界面の急峻
性は飛躍的に向上した。その結果、その成長結晶により
作られるデバイスのコストも大幅に削減することが可能
とな枚非常に実用的効果は大きい。Effects of the Invention The vapor phase growth method of the present invention deposits carbon on the back surface of the substrate and heats the substrate uniformly, so high quality crystals are maintained with good uniformity over a large area, and there is little variation in composition and impurity concentration. , the transition layer at the heterointerface was less than 10 Å, and the steepness of the interface was dramatically improved. As a result, it is possible to significantly reduce the cost of devices manufactured using the grown crystal, which has a great practical effect.

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

第１図は本発明の一実施例における気相成長方法に用い
る気相成長装置の概略溝底図、第２図は従来の気相成長
方法に用いる気相成長装置の概略構成図である。 ６・・・・・・結晶成長室、７・・・・・・高周波コイ
ル、１３・・・・・・基板、２１・・・・・・炭素、２
０・・・・・・石英ガラス製サセプタっFIG. 1 is a schematic groove bottom diagram of a vapor phase growth apparatus used in a vapor phase growth method according to an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of a vapor phase growth apparatus used in a conventional vapor phase growth method. 6...Crystal growth chamber, 7...High frequency coil, 13...Substrate, 21...Carbon, 2
0...Quartz glass susceptor

Claims (1)

【特許請求の範囲】[Claims] 結晶成長室に反応ガスを導入し、前記結晶成長室内に載
置された基板に薄膜を形成する際、基板裏面に炭素を堆
積し、高周波誘導により前記炭素を加熱し、加熱された
炭素からの熱で前記基板を加熱して前記基板上に薄膜を
形成することを特徴とする気相成長方法。When a reactive gas is introduced into a crystal growth chamber and a thin film is formed on a substrate placed in the crystal growth chamber, carbon is deposited on the back surface of the substrate, the carbon is heated by high frequency induction, and the carbon is removed from the heated carbon. A vapor phase growth method comprising heating the substrate with heat to form a thin film on the substrate.