JPS61163109A

JPS61163109A - Preparation of polycrystalline si film

Info

Publication number: JPS61163109A
Application number: JP182085A
Authority: JP
Inventors: Hajime Ichiyanagi; 一柳　肇; Hiroshi Kawai; 弘川合
Original assignee: Sumitomo Electric Industries Ltd
Current assignee: Sumitomo Electric Industries Ltd
Priority date: 1985-01-08
Filing date: 1985-01-08
Publication date: 1986-07-23

Abstract

PURPOSE:To prepare polycrystalline Si film useful for semiconductor element, by growing crystal particles utilizing a pattern serving as a seed for the crystal growth provided on an electroconductive substrate in the stage of coagulating Si film which is formed on said substrate by melting and then coagulating. CONSTITUTION:SiO2 film 2 is formed on an electroconductive substrate 1 such as stainless steel plate, etc. Then, a grating pattern is formed by such as reactive ion etching process. After forming polycrystalline Si film 4 by normal pressure CVD process or vapor deposition process, etc., the growth of crystal is proceeded by such as laser melting process, etc. to prepare polycrystalline Si film. When amorphous Si film 5 is formed from the above described polycrystalline Si film by such as plasma CVD process at 250 deg.C, and a transparent electrode 6 is formed at 250 deg.C by ion plating process, an amorphous Si solar cell is obtd. Polycrystalline Si film having large crystal size if formed from a pattern of SiO2 such as fine lines on the electroconductive substrate as crystal seed and the electroconductive substrate serves as rear electrode. Thus, the Si film is useful as semiconductor element.

Description

【発明の詳細な説明】（産業上の利用分野）本発明は、多結晶シリコン（Ｓｉ）膜の製造方法詳しく
は半導体素子に利用出来る多結晶Ｓｉ膜の製造方法に関
するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing a polycrystalline silicon (Si) film, and more particularly to a method of manufacturing a polycrystalline Si film that can be used in semiconductor devices.

（従来技術）この種の多結晶Ｓｉ膜の製造に於いて、絶縁性基板上で
のＳｉ膜の結晶粒を大きくする努力は従来から例えば次
の様な手段で行われている。(Prior Art) In manufacturing this type of polycrystalline Si film, efforts have been made to enlarge the crystal grains of the Si film on an insulating substrate, for example, by the following methods.

（１）第４図参照石英基板（７）に３．８μピツチ（Ｐ）、０．１μ深さ
くＤ）の溝（８）を作り、この上に半導体Ｓｉ膜膜形後
後レーザーアニール単結晶化する。(1) Refer to Fig. 4. A groove (8) of 3.8μ pitch (P) and 0.1μ depth (D) is made in the quartz substrate (7), and a semiconductor Si film is formed on the groove (8) after laser annealing single crystal. become

（２）第５図参照石英基板（７）上に極めて微細な粒径の多結晶Ｓｉ膜（
４）を作り、その上に更に５０μピツチ（Ｐつで５ｉ０
２膜（２）を帯状に形成し、レーザーアニールする、し
かるときは帯状のＳ　ｉ０２膜（２）の下に粒界が集中
し５０μピツチの部分は単結晶化する。(2) Refer to Figure 5. Polycrystalline Si film with extremely fine grain size (
4), and then add another 50μ pitch (5i0 with P).
2 film (2) is formed into a band-like shape and laser annealed. When this happens, the grain boundaries are concentrated under the band-like SiO2 film (2), and the 50 μm pitch portions become single crystals.

（発明が解決しようとする問題点）しかし乍ら上記に於いては、裏面電極がないため半導体
素子に用いることが出来ない。(Problems to be Solved by the Invention) However, the above method cannot be used for semiconductor devices because there is no back electrode.

上記に鑑み本発明は半導体素子に用いることの出来る多
結晶Ｓｉ膜の製造方法を提供するものである。In view of the above, the present invention provides a method for manufacturing a polycrystalline Si film that can be used for semiconductor devices.

（問題点を解決するための手段）即ち本発明の多結晶Ｓｉ膜の製造方法の概略は、ステン
レス板等導電性基板上に結晶成長の核となる模様を形成
し、その上に多結晶Ｓｉを成膜後レーザー等でＳｉを溶
かして一方向凝固により階段部を核にして結晶粒成長さ
せ４粒径の大きな多結晶Ｓｉを得るものである。(Means for Solving the Problems) That is, the outline of the method for manufacturing a polycrystalline Si film of the present invention is to form a pattern that will become a nucleus for crystal growth on a conductive substrate such as a stainless steel plate, and then deposit polycrystalline Si on the pattern. After forming a film, the Si is melted using a laser or the like, and crystal grains are grown using the stepped portions as nuclei through unidirectional solidification to obtain polycrystalline Si with four large grain sizes.

（作用）上記により裏面電極を持った、結晶粒の大きな多結晶Ｓ
ｉ膜を作ることが出来る。(Function) Polycrystalline S with large crystal grains has a back electrode as described above.
i-film can be made.

以・下水発明を例示の第１図について詳細に説明する。The sewage invention will now be described in detail with reference to FIG. 1 as an example.

第１図は多結晶Ｓｉ薄膜を用いたアモルファスシリコン
太陽電池の製造工程の７０−チャートである。FIG. 1 is a 70-chart of the manufacturing process of an amorphous silicon solar cell using a polycrystalline Si thin film.

（工ａｌ）　　ステンレス（ＳＵＳ　）基板（１）を準
備する（注）　基板はその他、金属を全面に蒸着したガ
ラス等導電性であればよい。(English Al) Prepare a stainless steel (SUS) substrate (1) (Note) The substrate may be made of conductive material such as glass with metal deposited on its entire surface.

（工程２）　基板（１）上に５ｉＯｚ膜（２）を形成す
る。(Step 2) A 5iOz film (2) is formed on the substrate (1).

（注）　その形成法は真空蒸着、イオンプレーテングＣ
ＶＤ、プラズマＣＶＤ等何でもよい。膜厚はＳｉ（後述
）の約ユ〜］の厚さが適当である。薄いと効果がない、即ち粒成長の核とならない。(Note) The formation method is vacuum evaporation, ion plating C
Any method such as VD or plasma CVD may be used. The appropriate film thickness is approximately 100 mm thick for Si (described later). If it is thin, it is ineffective, that is, it does not become a nucleus for grain growth.

又厚いと後述工程５のあとでＳｉ表面が平滑にならない、これは電池特性を悪くする。Also, if it is thick, the Si surface will be removed after step 5 described below. is not smooth, this is due to battery characteristics. make things worse.

（工程３）ＳｉＯｘ膜（２）からなるグレーティングを
形成する。(Step 3) A grating made of SiOx film (2) is formed.

（注）　例えば反応性イオンエツチングにょる。(Note) For example, reactive ion etching.

グレーティング模様はたて縞状（第３図（ａ））、山形状（第３．堕（ｂ））等でよい。上
記の具体的作業は第２図（ａｌ、（ｂｌ、（Ｃ１、（ｄ
ｌに例示する様に、ＳＯ８基板（１）上にＳｉＯ２膜（
２）を形成したもの（図（１）参照）の上にレジスト（
３）を作る（図（ｂｌ参照）。これはフォトリソグラフ
ィー技術でパターン化したレジストを作る。次にＣＦ４ガスでＳｉＯ２をドライエツジ
ングする（図ｆｃｌ参照）。The grating pattern may be a vertical striped pattern (FIG. 3(a)), a mountain pattern (FIG. 3(b)), or the like. The above concrete work is shown in Figure 2 (al, (bl, (C1, (d)
As illustrated in 1, a SiO2 film (
2) is formed (see figure (1)), and the resist (
3) is made (see figure (bl)). This creates a patterned resist using photolithography technology. Next, SiO2 is dry etched with CF4 gas (see figure fcl).

この後レジスト（３）を除去する（図（ｄｌ参照）。After that, the resist (3) is removed (see figure (dl)).

（工程４）　多結晶Ｓｉ膜（４）を形成する。(Step 4) Form a polycrystalline Si film (4).

（注）　膜厚は例えば咎３０μである。膜形成は下記■
、＠、θ等による。(Note) The film thickness is, for example, 30μ. Film formation is as below ■
, @, θ, etc.

■　常圧ＣＶＤＳｉＣ／４−１−８２＋ドーパント（ｎ型にするときＰ
Ｈｇ、Ｐ型にするときＢ２Ｈ６）、〜１１５０℃ ＠　蒸着ＳｉにＢ又はＰを混入した蒸発源をとばす。■ Normal pressure CVD SiC/4-1-82 + dopant (P when making n-type
When converting to Hg or P type, B2H6), ~1150°C @ evaporation source in which B or P is mixed into vapor-deposited Si is evaporated.

θ　減圧ＣＶＤ５ｉＨａ＋ドーパント（ｎ型にするときＰＨ６、Ｐ型に
するときＢ２Ｈ６）、〜７００℃。θ Low pressure CVD 5iHa + dopant (PH6 for n-type, B2H6 for p-type), ~700°C.

上記に於いて膜形成スピードは常圧が高速、欠陥束の理由でより良い。In the above, the film formation speed is normal pressure. The faster it is, the better it is because of the defect bunch.

（工程５）　結晶粒を成長させる。(Step 5) Growing crystal grains.

（注）　例えばレーザーメルティングによる。(Note) For example, by laser melting.

一方向凝固がポイントであり、レーザーに限らず電気炉から徐々に引出す方法もよい。何れもＳｉを一旦とかす。The key is unidirectional solidification, and Gradually withdrawn from electric furnaces, not limited to Another method is also good. All of them have Si once. vinegar.

（工程６）　　アモルファスシリコン膜（５）を形成す
る。(Step 6) Form an amorphous silicon film (5).

（注）　例えばプラズマＣＶＤ、２５０℃による。(Note) For example, by plasma CVD at 250°C.

アモルファスシリコン膜は例えばａ−５ｉ（ｎ（３０００Ａ’）／Ｐ（３００Ａ’）／１
（５０００Ａ”）／ｎ（２００Ａ”）：）（工程７）　透明電極（６）を形成する。For example, the amorphous silicon film is a-5i(n(3000A')/P(300A')/1
(5000A'')/n(200A''):) (Step 7) Form a transparent electrode (6).

（注）　例えばイオンブレーティング、２５０℃による
。(Note) For example, by ion blating at 250°C.

透明電極は例えばＩＴＯ（Ｉｎｄｉｕｍ　−Ｔｉｎ　−０ｘｉｄｅ　）　
（６ＱＱＡ’）上記工程５までが本発明の内容である。The transparent electrode is, for example, ITO (Indium-Tin-Oxide).
(6QQA') The content of the present invention is up to step 5 above.

（実施例）以下に本発明の理解を助けるため実施例を述べる。(Example) Examples will be described below to help understand the present invention.

■　ステンレス板に５ｉ０２を電子ビーム蒸着した（膜
厚１μ）。■ 5i02 was electron beam deposited on a stainless steel plate (film thickness: 1μ).

■　フォトレジストをコートし、パターン露光してフォ
トレジストをパターン化した。■ The photoresist was coated and patterned by pattern exposure.

■　ＣＦａガスで５ｉ０２をエツチングした。■ 5i02 was etched with CFa gas.

■　フォトレジストを除去した。■ The photoresist was removed.

■　常圧ＣＶＤでＳｉ膜（膜厚１ｏμ）形成した（ガス
：　ＳｉＣ／４＋Ｈ２、温度：１１５０℃）。粒径は５
μであった。(2) A Si film (thickness: 1 μm) was formed by atmospheric pressure CVD (gas: SiC/4+H2, temperature: 1150° C.). Particle size is 5
It was μ.

■　レーザー走査で一方向凝固させた（１２ＷのＹＡＧ
レーザー使用）。粒径は５００μであった。これは太陽
電池として充分使用に耐える値である。■ Unidirectionally solidified by laser scanning (12W YAG
(using laser). The particle size was 500μ. This value is sufficient to withstand use as a solar cell.

（発明の効果）以上の様な本発明によると下記の様な効果がある。即ち
導電性基板上に設けた５ｉＯｚの微細な筋等模様が粒成
長の核となる。従って安価な基板上に粒径の大きな多結
晶Ｓｉ膜を得ることが出来る、しかも導電性基板が裏電
極となり、半導体素子としての使用が可能となる。(Effects of the Invention) The present invention as described above has the following effects. That is, the 5 iOz fine stripes and other patterns provided on the conductive substrate become the nucleus of grain growth. Therefore, a polycrystalline Si film with a large grain size can be obtained on an inexpensive substrate, and the conductive substrate serves as a back electrode, making it possible to use it as a semiconductor element.

[Brief explanation of drawings]

第１図は本発明を説明するための図であって、多結晶Ｓ
ｉ膜を用いたアモルファスシリコン太陽電池の製造工程
のフローチャート、第２図（ａｌ、（ｂｌ、（Ｃ１、（
ｄ）は第１図のフローチャートの工程３の手順を説明す
る図、第３図体）、（ｂｌは第１図のフローチャートの
工程（３）のグレーティング形成模様を示す斜視図、第
４図及び第５図は共に従来の絶縁基板上でＳｉ膜の結晶
粒を大きくする手段を説明する斜視図を夫々例示してい
る。（１）・・・ＳＵＳ等の導電性基板、（２）・・・５ｉ
Ｏｚ膜、（３）・・・レジスト、（４）・・・多結晶Ｓ
ｉ膜、＋５１・・・アモルファスシリコン膜、（６）・
・・透明電極、（７）・・・石英基板、（８）・・・溝
、ｆｌ　　図ｉ２図（ａ）（ｂ）（ｄ）オ　３　図（ａ）　　　　　　　　（ｂ）FIG. 1 is a diagram for explaining the present invention, in which polycrystalline S
Flowchart of manufacturing process of amorphous silicon solar cell using i-film, FIG. 2 (al, (bl, (C1, (
d) is a diagram explaining the procedure of step 3 in the flowchart in FIG. Figures 5 and 5 each illustrate a perspective view illustrating means for enlarging the crystal grains of a Si film on a conventional insulating substrate. (1) Conductive substrate such as SUS, (2)... 5i
Oz film, (3)...resist, (4)...polycrystalline S
i film, +51... amorphous silicon film, (6)
...Transparent electrode, (7)...Quartz substrate, (8)...Groove, fl Figure i2 (a) (b) (d) O Figure 3 (a) (b)

Claims

[Claims]

(1) A polycrystalline material characterized by forming a Si film on a conductive substrate with a pattern forming a nucleus for crystal growth, and growing grains using the pattern in the process of melting and solidifying the Si. Method for manufacturing Si film.

(2) The method for manufacturing a polycrystalline Si film according to claim (1), wherein the conductive substrate is made of stainless steel.

(3) The method for producing a polycrystalline Si film according to claim (1), wherein the conductive substrate is made of glass on which metal is deposited over the entire surface.

(4) A method for producing a polycrystalline Si film according to claim (1), in which Si grains are grown using a laser.

(5) A method for manufacturing a polycrystalline Si film according to claim (1), in which grains of Si are grown using an electric furnace.

(6) The method for manufacturing a polycrystalline Si film according to claim (1), wherein the pattern formed on the conductive substrate is in the form of vertical stripes.

(7) The method for manufacturing a polycrystalline Si film according to claim (1), wherein the pattern formed on the conductive substrate is in the shape of a mountain.

(8) The method for producing a polycrystalline Si film according to claim (1), wherein the pattern formed on the conductive substrate and serving as a nucleus for crystal growth is a pattern of SiO_2.