JPH02275620A - N-type silicon thin film - Google Patents
N-type silicon thin filmInfo
- Publication number
- JPH02275620A JPH02275620A JP1220198A JP22019889A JPH02275620A JP H02275620 A JPH02275620 A JP H02275620A JP 1220198 A JP1220198 A JP 1220198A JP 22019889 A JP22019889 A JP 22019889A JP H02275620 A JPH02275620 A JP H02275620A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- silicon thin
- optical
- amorphous
- present
- 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.)
- Pending
Links
- 239000010409 thin film Substances 0.000 title claims abstract description 70
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 65
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 62
- 239000010703 silicon Substances 0.000 title claims abstract description 62
- 230000003287 optical effect Effects 0.000 claims abstract description 38
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 9
- 239000001257 hydrogen Substances 0.000 claims abstract description 9
- 230000004913 activation Effects 0.000 claims abstract description 6
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910052731 fluorine Inorganic materials 0.000 claims abstract description 4
- 239000011737 fluorine Substances 0.000 claims abstract description 4
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims abstract description 3
- 229910052801 chlorine Inorganic materials 0.000 claims abstract description 3
- 239000000460 chlorine Substances 0.000 claims abstract description 3
- 229910052698 phosphorus Inorganic materials 0.000 claims description 5
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 4
- 238000002441 X-ray diffraction Methods 0.000 claims description 4
- 239000011574 phosphorus Substances 0.000 claims description 4
- 230000000737 periodic effect Effects 0.000 claims description 3
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 claims description 2
- 229910052785 arsenic Inorganic materials 0.000 claims description 2
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 claims description 2
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 claims description 2
- 229910052794 bromium Inorganic materials 0.000 claims description 2
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 claims 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 claims 1
- 229910052740 iodine Inorganic materials 0.000 claims 1
- 239000011630 iodine Substances 0.000 claims 1
- 239000013078 crystal Substances 0.000 abstract description 10
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 abstract description 9
- 229910021417 amorphous silicon Inorganic materials 0.000 abstract description 5
- 239000012535 impurity Substances 0.000 abstract description 5
- 229910021420 polycrystalline silicon Inorganic materials 0.000 abstract description 5
- PNDPGZBMCMUPRI-UHFFFAOYSA-N iodine Chemical compound II PNDPGZBMCMUPRI-UHFFFAOYSA-N 0.000 abstract description 2
- 239000010408 film Substances 0.000 description 27
- 239000007789 gas Substances 0.000 description 16
- 238000004519 manufacturing process Methods 0.000 description 14
- 239000002019 doping agent Substances 0.000 description 12
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 10
- 229910000077 silane Inorganic materials 0.000 description 8
- 239000000758 substrate Substances 0.000 description 7
- 230000007423 decrease Effects 0.000 description 5
- 125000005843 halogen group Chemical group 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 239000004065 semiconductor Substances 0.000 description 5
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 4
- 229910052796 boron Inorganic materials 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 238000002156 mixing Methods 0.000 description 4
- XYFCBTPGUUZFHI-UHFFFAOYSA-N Phosphine Chemical compound P XYFCBTPGUUZFHI-UHFFFAOYSA-N 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000001228 spectrum Methods 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000013081 microcrystal Substances 0.000 description 2
- 239000003921 oil Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 229910000073 phosphorus hydride Inorganic materials 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- UJKWLAZYSLJTKA-UHFFFAOYSA-N edma Chemical compound O1CCOC2=CC(CC(C)NC)=CC=C21 UJKWLAZYSLJTKA-UHFFFAOYSA-N 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- OBCUTHMOOONNBS-UHFFFAOYSA-N phosphorus pentafluoride Chemical compound FP(F)(F)(F)F OBCUTHMOOONNBS-UHFFFAOYSA-N 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 238000005036 potential barrier Methods 0.000 description 1
- 238000005215 recombination Methods 0.000 description 1
- 230000006798 recombination Effects 0.000 description 1
- 150000004756 silanes Chemical class 0.000 description 1
- 150000003376 silicon Chemical class 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
Landscapes
- Inorganic Compounds Of Heavy Metals (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Photovoltaic Devices (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は、シリコン薄膜に関し、さらに詳しくのべると
、任意の基板上にプラズマ雰囲気下で成膜して得られる
低抵抗のシリコン薄膜に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a silicon thin film, and more specifically, to a low resistance silicon thin film that can be formed on any substrate in a plasma atmosphere.
シランＳ ｉ Ｈ４にドーパントガスを混合したものを
原料ガスとし、プラズマ雰囲気下で任意の基板上にシリ
コン薄膜を製造する方法は周知である。従来のこの種の
方法で成膜したシリコン薄膜は完全な非晶質である。非
晶質膜については、そのＸ線回折像はハローパターンを
示し、そしてこの非晶質のシリコン薄膜半導体の電気伝
導度は、Ｎ型膜で最大１０−２Ω−’ｃ ｍ−’程度、
Ｐ型膜で１０−”Ω−’ｃ ｍ−’程度であり、電気伝
導度の温度依存性より求めた活性化エネルギーも、Ｐ型
膜およびＮ型膜ともに０．２ｅＶ程度とかなり大きく、
金属とのオートミック性が良いフェルミ準位が十分に縮
退したＰ９型またはＮ０型膜になっているとはいい難い
（例えばフイロソフイカル・マガシ”、ｉ ［ＰＨＩＬ
Ｏ３ＯＰＨＩｃＡＬ ＭＡＧＡＺＩＮＥＩ ３３．９３
５ （１９７６）参照）。特にＰ型膜の場合、高電気伝
導度にすればするほど光学的バンドギャップ（光学的禁
制帯幅）が大幅に縮まってくる（例えばフィジカル・レ
ビ−Ｌ −（ＰＨＹＳＩＣＡＬ ＲＥＶＩＥＷｌｌ上、
２０４１ （１９７９）参照）。このため、特に太陽
電池を目的としたＰ−Ｎ接合半導体素子あるいはＰ−Ｉ
−Ｎ接合半導体素子を製造した場合、Ｐ層膜についてい
えばＰ層膜の光学的バンドギャップが狭まるため、窓側
２層から入射した光が接合部の活性Ｈ（Ｐ／ＮまたはＰ
／Ｉ界面）に到達する前にＰｌ’！で吸収されてしまう
とともに、接合部かへテロ接合となり、ポテンシャル障
壁高さが低くなるため開放端電圧が下がってしまう。他
方Ｎ層についていえば、金層とのオーミック接合が良（
ないと同時に直列抵抗が高いためフィルファクター（効
率の曲線因子）が下がってしまう。これらのことは、結
局、光のエネルギー変換効率が低下することを意味する
。A method of manufacturing a silicon thin film on an arbitrary substrate in a plasma atmosphere using a mixture of silane S i H4 and a dopant gas as a raw material gas is well known. The silicon thin film formed by this type of conventional method is completely amorphous. As for an amorphous film, its X-ray diffraction pattern shows a halo pattern, and the electrical conductivity of this amorphous silicon thin film semiconductor is approximately 10-2Ω-'cm-' at the maximum for an N-type film.
It is about 10-''Ω-'cm-' for the P-type film, and the activation energy determined from the temperature dependence of electrical conductivity is also quite large, about 0.2 eV for both the P-type film and the N-type film.
It is difficult to say that the film is a P9 type or N0 type film with a sufficiently degenerate Fermi level that has good atomic properties with metals (for example, ``Firosophical Magashi'', i [PHIL
O3OPHIcAL MAGAZINEI 33.93
5 (1976)). Particularly in the case of P-type films, the higher the electrical conductivity, the more the optical bandgap (optical forbidden band width) will shrink (for example, on the PHYSICAL REVIEW II).
2041 (1979)). For this reason, P-N junction semiconductor devices or P-I
- When manufacturing a N-junction semiconductor device, the optical bandgap of the P-layer film is narrowed, so light incident from the window-side two layers is transmitted to the active H (P/N or P) of the junction.
/I interface) before reaching Pl'! At the same time, the junction becomes a heterojunction, and the potential barrier height decreases, causing the open circuit voltage to decrease. On the other hand, regarding the N layer, it has good ohmic contact with the gold layer (
At the same time, the fill factor (fill factor of efficiency) decreases because the series resistance is high. These things ultimately mean that the light energy conversion efficiency decreases.
一方、シランＳ ｉ Ｈ４のＣＶ Ｄ （Ｃｈｅｍｉｃ
ａｌ Ｖａｐｏｒ Ｄｅｐｏｓｉｔｉｏｎ）等による多
結晶薄膜は、電気伝導度は高いものの光学的バンドギャ
ップ（光学的禁制帯幅）は１．２ｅＶ程度であり、太陽
スペクトルに十分適合していない。また、存在する結晶
粒塊界面が電子正孔対の再結合点となるばかりでな（、
電流漏洩の原因ともなる。On the other hand, CV D (Chemical
Although polycrystalline thin films manufactured by Al Vapor Deposition and others have high electrical conductivity, their optical band gap (optical forbidden band width) is about 1.2 eV, which is not sufficiently compatible with the solar spectrum. In addition, the existing crystal grain agglomerate interfaces not only serve as recombination points for electron-hole pairs (
It also causes current leakage.
それゆえ、本発明の目的は、前述の欠点を除去し、電気
抵抗が小さく、光学的バンドギャップ（光学的禁制帯幅
）が十分大きく、非晶質シリコン薄膜の長所と多結晶シ
リコン薄膜の長所を併有したようなシリコン薄膜を提供
することである。Therefore, the purpose of the present invention is to eliminate the above-mentioned drawbacks, have a small electrical resistance, a sufficiently large optical bandgap (optical forbidden band width), and achieve the advantages of an amorphous silicon thin film and a polycrystalline silicon thin film. It is an object of the present invention to provide a silicon thin film having the following properties.
本発明の他の目的は、特定の範囲の結晶粒子を有し、電
気伝導度が太き（、かつ光学的バンドギャップ（光学的
禁制帯幅）の大きいシリコン薄膜を提供することである
。Another object of the present invention is to provide a silicon thin film that has crystal grains in a specific range, has thick electrical conductivity (and has a large optical band gap).
本発明のさらに他の目的は、従来製造困難であった電気
伝導度が大きく、かつドーピング効果の侵れたＮ型シリ
コン薄膜を提供することである。Still another object of the present invention is to provide an N-type silicon thin film that has high electrical conductivity and is free from doping effects, which has been difficult to manufacture in the past.
本発明のさらに他の目的は、任意の基板上に、プラズマ
雰囲気下で得られる低抵抗で光学的バンドギャップ（光
学的禁制帯幅）の大きいシリコン薄膜を提供することで
ある。Still another object of the present invention is to provide a silicon thin film with low resistance and a large optical bandgap (optical forbidden band width) that can be obtained in a plasma atmosphere on any substrate.
本発明のシリコン薄膜は、フッ素、塩素、臭素、沃素お
よび水素の群から選択された少なくとも一種の元素なら
びに不純物元素を含有して大部分がシリコン原子からな
るシリコン薄膜であるが、その原子配列の規則性、すな
わち薄膜構造に大きな特徴があり、非晶質の層の中に微
結晶部分が混在分散していることが顕著な特徴である。The silicon thin film of the present invention is a silicon thin film that contains at least one element selected from the group of fluorine, chlorine, bromine, iodine, and hydrogen and an impurity element, and is mostly composed of silicon atoms, but the atomic arrangement is It is characterized by its regularity, that is, its thin film structure, and its remarkable feature is that microcrystalline portions are mixed and dispersed within the amorphous layer.
すなわち、Ｘ線回折を行なうと、通常のプラズマ雰囲気
下で製造した非晶質シリコン薄膜は、幅広いなだらかな
ハローパターンを有し、シャープなピークが認められな
いスペクトルを示し、他方、化学蒸着および高温アニー
ル等で製造した多結晶シリコン薄膜は、シリコンの結晶
格子に由来する明確な強いピークを有するスペクトルを
示す。それに比べて、本発明のシリコン薄膜は、ハロー
パターンの上にシリコン結晶格子に由来すると推定され
る微弱なピークを５ｉ（１１１）またはＳｉ （２２０
）の近傍に示す。本発明のシリコン薄膜中の微結晶の平
均粒径は、前述のピークの半値幅からシェラ−（５ｃｈ
ｅｒｒｅｒ）の式を用いて計算することができ、約１０
０Å以上約５００Å以下である。この粒径範囲の微結晶
は、通常の太陽光の波長域では光学上阻害物となること
がなく、かつ電気伝導度を上昇させ得るごとき範囲のも
のである。That is, when X-ray diffraction is performed, an amorphous silicon thin film produced in a normal plasma atmosphere shows a spectrum with a broad gentle halo pattern and no sharp peaks, whereas A polycrystalline silicon thin film manufactured by annealing or the like exhibits a spectrum with clear and strong peaks originating from the crystal lattice of silicon. In comparison, the silicon thin film of the present invention has a weak peak estimated to originate from the silicon crystal lattice on the halo pattern, such as 5i (111) or Si (220
) is shown near. The average grain size of the microcrystals in the silicon thin film of the present invention can be determined from the half-width of the above-mentioned peak by Scherer (5ch
errer) and can be calculated using the formula of approximately 10
The thickness is 0 Å or more and about 500 Å or less. Microcrystals in this particle size range do not become an optical hindrance in the wavelength range of normal sunlight and can increase electrical conductivity.
本発明のシリコン薄膜においては、前述のごとく非晶質
層中に微細な結晶粒が存在することが、以下に説明する
非晶質としてのシリコン薄膜の長所、すなわち、光学的
バンドギャップ（光学的禁制帯幅）を十分大きく保持し
ていること、および多結晶シリコン薄膜の長所、すなわ
ち電気伝導度が著しく大きいことを合わせ保有すること
に宇接に作用しているものと推定される。In the silicon thin film of the present invention, the presence of fine crystal grains in the amorphous layer as described above is an advantage of the silicon thin film as an amorphous material, which will be explained below, that is, the optical band gap (optical It is presumed that this is due to the fact that the film has a sufficiently large forbidden band width and the advantage of polycrystalline silicon thin films, that is, extremely high electrical conductivity.
本発明のシリコン薄膜において、ドーピングされる不純
物元素として種々のものが使用されるが、それがリン、
ヒ素等の元素周期律表第Ｖ族の場合は、Ｎ型半導体の特
性を有するシリコン薄膜が得られ、他方、ホウ素、アル
ミニウム等の元素周期律表第■族の場合は、Ｐ型半導体
の特性を有するシリコン薄膜が得られる。前者のシリコ
ン薄膜は、電気伝導度が約１０−ＩΩ−１ｃｍ−’〜１
０゜Ω”１ｃｍ−’に達することが、他方、後者は、約
１０−２Ω−１ｃｍ−１〜約１０−１Ω−１ｃｍ−’に
達することが特徴である。同様のドーピングにおいて、
電気伝導度の活性化エネルギが約０．２ｅＶよりも小さ
くなり、多（は、約０．１ｅＶ以下となり、ドーピング
効率が良（、フェルミ準位が十分に縮退し、金属とのオ
ーミック接合性の優れたＮ型およびＰ型シリコン薄膜が
得られることも特徴である。また、本発明のシリコン薄
膜は、Ｎ型、Ｐ型ともに、ドーピングによっても光学的
バンドギャップ（光学的禁制帯幅）が十分大きく保持さ
れており、多結晶質の約１．２ｅＶに比べ、約１．３ｅ
Ｖ〜約１．８ｅＶとかなり大きい値を有し、また、特に
Ｐ型溝膜においては、従来得られなかった高電気伝導度
と光学的バンドギャップ（光学的禁制帯幅）の優れた特
性を同時に有するものである。これらの効果も、本発明
のシリコン薄膜が、完全な非晶質でなく、完全な多結晶
でもない新規な結晶構造のシリコン薄膜であることを証
するものである。In the silicon thin film of the present invention, various impurity elements are used for doping, including phosphorus,
In the case of elements belonging to group V of the periodic table, such as arsenic, a silicon thin film having the characteristics of an N-type semiconductor is obtained, while in the case of elements belonging to group Ⅰ of the periodic table, such as boron and aluminum, the characteristics of a p-type semiconductor are obtained. A silicon thin film having the following properties is obtained. The former silicon thin film has an electrical conductivity of about 10-IΩ-1cm-' to 1
0° Ω"1 cm-', while the latter is characterized by reaching approximately 10-2 Ω-1 cm-1 to approximately 10-1 Ω-1 cm-'. In a similar doping,
The activation energy of electrical conductivity is less than about 0.2 eV, and the doping efficiency is less than about 0.1 eV, and the Fermi level is sufficiently degenerated, and the ohmic contact with the metal is improved. Another feature is that excellent N-type and P-type silicon thin films can be obtained.Also, the silicon thin film of the present invention has a sufficient optical band gap (optical forbidden band width) even by doping for both N-type and P-type silicon thin films. It is maintained at a high value of approximately 1.3eV compared to approximately 1.2eV for polycrystalline materials.
It has a fairly large value of V~1.8eV, and also has excellent characteristics of high electrical conductivity and optical bandgap (optical forbidden band width), which were previously unobtainable, especially in P-type groove films. At the same time. These effects also prove that the silicon thin film of the present invention is a silicon thin film with a novel crystal structure that is neither completely amorphous nor completely polycrystalline.
次に、本発明のシリコン薄膜の製造方法について述べる
と、まず、シランＳｉ Ｈ４またはハロゲン化シランＳ
ｆ Ｈｏ〜ｓＸ４〜１ （Ｘ：へロゲン元素）のいず
れか、またはその２種以上の混合ガスをヘリウム、アル
ゴン等の希ガスまたは水素ガスで約１＝１より大きい高
割合で希釈したものにドーパントガスが所定の割合で混
合されるが、この混合希釈の順序は特に限定されるもの
ではない。Next, the method for manufacturing a silicon thin film of the present invention will be described. First, silane Si H4 or halogenated silane S
f Ho~s Although the dopant gases are mixed at a predetermined ratio, the order of mixing and dilution is not particularly limited.
この混合ガスに約０．２Ｗ／ｃｒｔｒより大きいプラズ
マ放電電力密度の電力を投入してプラズマ状態とし、そ
の中におかれた基板（ガラス、プラスチックまたは金属
等）上に成膜すれば、ドーパントである不純物原子が効
果的に４配位でシリコンネットワーク内に組み込まれ、
光学的バンドギャップ（光学的禁制帯幅）を狭めること
なく高電気伝導度のシリコン薄膜が形成される。ここで
シランＳ ｉ Ｈ４を水素または希ガスで高割合で希釈
する目的は、通常成膜時に大電力を投入したときには、
シランＳ ｉ Ｈ４の分解が促進されて成膜速度が太き
（なるため、ドーパントである不純物が効率良く４配位
でシリコンネットワーク中に入り難くなる。そこで、大
電力を投入しても成膜速度が大きくならないように（望
ましくは４人／ｓｅｃ以下）シランＳｉ Ｈ４を水素ま
たは希ガスで希釈するのである。このような条件で製造
した膜のＸ線回折像は、微結晶粒が非晶質の中に混在し
ていることが観測され、そしてこのような微細な結晶粒
の存在が、非晶質としての膜の光学的特性を賦与しなが
ら電気抵抗を著しく低下させているものと推定される。If power with a plasma discharge power density greater than approximately 0.2 W/crtr is applied to this mixed gas to create a plasma state, and a film is formed on a substrate (glass, plastic, metal, etc.) placed in the plasma state, the dopant can be formed. A certain impurity atom is effectively incorporated into the silicon network in a 4-coordination manner,
A silicon thin film with high electrical conductivity can be formed without narrowing the optical bandgap (optical forbidden band width). The purpose of diluting silane S i H4 with hydrogen or a rare gas at a high rate is that when a large amount of power is normally applied during film formation,
The decomposition of silane S i H4 is promoted and the film formation rate becomes thick (this makes it difficult for impurities, which are dopants, to efficiently enter the silicon network with 4 coordinations. The silane Si H4 is diluted with hydrogen or a rare gas so as not to increase the speed (preferably 4 people/sec or less). It is assumed that the existence of such fine crystal grains significantly reduces the electrical resistance while imparting the optical properties of the amorphous film. be done.
かかる微結晶粒の粒子径は、Ｘ線回折像によれば約１０
０Å〜約５００人の範囲のものである。According to the X-ray diffraction image, the particle size of such microcrystalline grains is about 10
It ranges from 0 Å to about 500 people.
以下図面を参照して、本発明によるシリコン薄膜の膜特
性および当該シリコン薄膜の製造方法の実施例について
説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of film characteristics of a silicon thin film and a method for manufacturing the silicon thin film according to the present invention will be described below with reference to the drawings.
第１図において、混合容器１を含めた全装置系を油回転
ポンプ２および油拡散ポンプ３を使って約１０−’ｔｏ
ｒｒの真空度まで真空にし、つぎにシランボンベ４およ
び水素ボンベ５、さらにドーパントガスボンベ６または
７よりガスを混合容器１に所要の割合で導入し、混合す
る。混合されたガスを流量計８を通して真空容器９中に
一定流量で導入する。メインバルブ１０で操作して真空
容器９中の真空度を真空計１１で監視しながら所要の圧
力に維持する。高周波発振器１２で電極１３および１３
′間に高周波電圧を印加してグロー放電を発生させる。In FIG. 1, the entire equipment system including the mixing vessel 1 is pumped approximately 10-'to
The mixture is evacuated to a vacuum degree of rr, and then gases are introduced into the mixing container 1 at a required ratio from the silane cylinder 4, the hydrogen cylinder 5, and the dopant gas cylinder 6 or 7, and mixed. The mixed gas is introduced into the vacuum vessel 9 through the flow meter 8 at a constant flow rate. The main valve 10 is operated to maintain the required pressure while monitoring the degree of vacuum in the vacuum container 9 with a vacuum gauge 11. High frequency oscillator 12 with electrodes 13 and 13
A high-frequency voltage is applied between ′ to generate glow discharge.
基板１５はヒーター１４で加熱された基台上に載置され
、ヒーターで所要の温度に加熱されており、この基板１
５上にドープされた水素化シリコン薄膜が成膜される。The substrate 15 is placed on a base heated by the heater 14 and heated to a required temperature by the heater.
A thin film of doped hydrogenated silicon is deposited over 5.
第１表に本発明による製造方法の実施例および生成され
た膜の特性を従来の製造法との対比においてまとめた。Table 1 summarizes examples of the manufacturing method according to the present invention and the characteristics of the produced films in comparison with conventional manufacturing methods.
この表で、Ｎｏ、 １〜Ｎｏ、 ３は従来の方法によ
り製造したＰ型シリコン薄膜であり、それについての成
膜条件と膜特性が示されている。Ｎｏ、 ４およびＮｏ
、 ５が本発明により製造したＰ型シリコン薄膜の実施
例である。このＮｏ、 ４およびＮｏ、 ５においては
、Ｓ Ｉ Ｈ４が水素ガスで３０倍に希釈され、０．８
Ｗおよび１．６Ｗの高電力がそれぞれ投入されている。In this table, No. 1 to No. 3 are P-type silicon thin films manufactured by conventional methods, and the film forming conditions and film characteristics thereof are shown. No. 4 and No.
, 5 are examples of P-type silicon thin films manufactured according to the present invention. In No. 4 and No. 5, S I H4 is diluted 30 times with hydrogen gas, and 0.8
High power of W and 1.6W are respectively input.
Ｎｏ、 ６〜Ｎｏ。No, 6~No.
９およびＮｏ、１１は従来の方法により製造したＮ型シ
リコン薄膜であり、 Ｎｏ、 １０およびＮｏ。9 and No. 11 are N-type silicon thin films manufactured by conventional methods;
１２が本発明により製造したＮ型シリコン薄膜の実施例
である。このＮｏ、１０およびＮｏ、１２においては、
ＳｉＨ，が水素ガスによって１０倍に希釈され、０．８
Ｗおよび１．６Ｗの電力が投入されている。12 is an example of an N-type silicon thin film manufactured according to the present invention. In this No. 10 and No. 12,
SiH, is diluted 10 times with hydrogen gas, 0.8
W and 1.6W of power are applied.
第２図は、本発明よりなるシリコン薄膜の電気伝導度を
ドーパントガス濃度の関数として示すものである。第２
図中曲線１６および１７は従来の製造方法によるもので
、陰極側プラズマ放電電力密度（投入プラズマ放電電力
／陰極側電極面積）にして約０．１Ｗ／ｃｒｒｒで成膜
したときのＰ型およびＮ型シリコン薄膜の電気伝導度を
示す。点１８．１９は、本発明よりなるＰ型シリコン薄
膜の電気伝導度で、成膜条件は、シランＳ ｉ Ｈ４を
水素で３０倍に希釈し、すなわちＳｉＨ４：Ｈａ＝１：
３０の混合ガスを用い、ドーパントとしてジボランＢ、
Ｈ，をＳ ｉ Ｈ４に対して２％（体積基準）混合した
ものを原料ガスとして、プラズマ放電電力密度をそれぞ
れ０．８Ｗ／ｃｒｒｆおよび１．６Ｗ／ｃｒｒｆとした
ものである。点２０．２１は本発明よりなるＮ型シリコ
ン薄膜の電気伝導度で、成膜条件は、シランを水素で１
０倍に希釈し、すなわちＳｉＨ，：Ｈ，＝１ ： １０
の混合ガスを用い、ドーパントとして点２０は五フッ化
リンＰＦ、を１％（体積基準）混合したもの、点２１は
ホスフィンＰＨ，を４５００ｐｐｍ （体積基準）混合
したものを原料ガスとし、電力密度をそれぞれ０．８Ｗ
／ｃｒｒｒおよび１．６Ｗ／ｃｒｒｒとしたものである
。第２図から、本発明のシリコン薄膜の電気伝導度が従
来の製造法によるものに比べ少なくとも２桁高（なって
いることが分る。FIG. 2 shows the electrical conductivity of a silicon thin film according to the invention as a function of dopant gas concentration. Second
Curves 16 and 17 in the figure are obtained by the conventional manufacturing method, and the P-type and N It shows the electrical conductivity of type silicon thin film. Point 18.19 is the electrical conductivity of the P-type silicon thin film according to the present invention, and the film forming conditions were silane S i H4 diluted 30 times with hydrogen, that is, SiH4:Ha=1:
Using a mixed gas of 30, diborane B as a dopant,
The raw material gas was a mixture of 2% (by volume) H, based on S i H4, and the plasma discharge power densities were set to 0.8 W/crrf and 1.6 W/crrf, respectively. Points 20 and 21 are the electrical conductivity of the N-type silicon thin film according to the present invention, and the film forming conditions were silane mixed with hydrogen at 1
Diluted 0 times, i.e. SiH,:H,=1:10
Point 20 is a mixture of 1% (volume basis) of phosphorus pentafluoride PF as a dopant, point 21 is a mixture of 4500 ppm (volume basis) of phosphine PH, and the power density is 0.8W each
/crrr and 1.6W/crrr. From FIG. 2, it can be seen that the electrical conductivity of the silicon thin film of the present invention is at least two orders of magnitude higher than that of the silicon thin film produced by the conventional manufacturing method.
第３図は、本発明のシリコン薄膜の電気伝導度の活性化
エネルギーをドーパントガス濃度の関数として示すもの
である。第３図中曲線２２．２３は従来の製造方法によ
るもので、第２図の曲線１６．１７に対応するものであ
る。点２４．２５．２６および２７は本発明によるもの
で、成膜条件は、それぞれ第２図中の点１８．１９．２
０および２１に対応する。第３図は、本発明のシリコン
薄膜の電気伝導度の活性化エネルギーが十分小さく、金
属とのオーミック性の良いフェルミ準位が縮退したＰ十
型またはＮ＋型膜であることを証明している。FIG. 3 shows the activation energy of electrical conductivity of a silicon thin film of the present invention as a function of dopant gas concentration. Curves 22 and 23 in FIG. 3 are based on the conventional manufacturing method and correspond to curves 16 and 17 in FIG. 2. Points 24, 25, 26 and 27 are according to the present invention, and the film forming conditions are the same as points 18, 19, and 2 in FIG. 2, respectively.
Corresponds to 0 and 21. Figure 3 proves that the activation energy of the electrical conductivity of the silicon thin film of the present invention is sufficiently small, and it is a P-type or N+-type film with a degenerate Fermi level and good ohmic properties with metals. .
第４図は、本発明よりなるシリコン薄膜中のホウ素濃度
およびリン濃度をそれぞれＳＩＭＳ法、ＥＤＭＡ法によ
り測定し、ドーパントガス濃度の関数として示すもので
ある。第４図中曲線２８．２９は従来の製造法によるも
ので、第２図中の曲線１６．１７に対応するものである
。点３０．３１．３２および３３は本発明によるもので
、成膜条件はそれぞれ第２図中の点１８．１９．２０お
よび２１に対応する。第４図は、本発明よりなるシリコ
ン薄膜中のホウ素濃度およびリン濃度が従来の製造方法
で成膜したものに比べて少ないことを示しており、本発
明の物質がきわめて優れた特性を有し、本発明による製
造法がきわめてドーピング効率の良い方法であることを
証明している。FIG. 4 shows the boron concentration and phosphorus concentration in the silicon thin film according to the present invention measured by the SIMS method and the EDMA method, respectively, as a function of the dopant gas concentration. Curves 28 and 29 in FIG. 4 are based on the conventional manufacturing method and correspond to curves 16 and 17 in FIG. Points 30, 31, 32 and 33 are according to the invention, and the deposition conditions correspond to points 18, 19, 20 and 21 in FIG. 2, respectively. Figure 4 shows that the boron and phosphorus concentrations in the silicon thin film of the present invention are lower than those formed by conventional manufacturing methods, indicating that the material of the present invention has extremely excellent properties. This proves that the manufacturing method according to the present invention is a method with extremely high doping efficiency.
第５図は、本発明よりなるＰ型シリコン薄膜の光学的バ
ンドギャップ（光学的禁制帯幅）をドーパントガス濃度
の関数として示した。ここで光学的バンドギャップ（光
学的禁制帯幅）はＦ丁ｈυα（ｈυ −Ｅ、）より求め
たものである。ここで、αは光吸収係数、ｈυは入射光
子エネルギ（ｅＶ）’、Ｅ０は光学的バンドギャップ（
光学的禁制帯幅）である。第５図中の曲線３４は従来の
製造法によるもので、第２図中の曲線１６に対応したも
のであり、ホウ素濃度の増加とともに光学的バンドギャ
ップが減少してい（。−力点３５．３６は本発明よりな
るシリコン膜についての測定値で、成膜条件はそれぞれ
第２図中の点１８．１９に対応している。第５図は、本
発明によるＰ型シリコン薄膜が、光学的バンドギャップ
（光学的禁制帯幅）が縮まることなく高電気伝導度を有
するということを示している。FIG. 5 shows the optical bandgap (optical forbidden band width) of a P-type silicon thin film according to the present invention as a function of dopant gas concentration. Here, the optical bandgap (optical forbidden band width) is determined from F-hυα(hυ-E,). Here, α is the optical absorption coefficient, hυ is the incident photon energy (eV)', and E0 is the optical band gap (
(optical forbidden band width). Curve 34 in FIG. 5 is based on the conventional manufacturing method and corresponds to curve 16 in FIG. 2, in which the optical bandgap decreases as the boron concentration increases (. are the measured values for the silicon film according to the present invention, and the film forming conditions correspond to points 18 and 19 in Figure 2. Figure 5 shows that the P-type silicon thin film according to the present invention has an optical band This shows that it has high electrical conductivity without narrowing the gap (optical forbidden band width).
第６図は、本発明によるシリコン薄膜（膜厚的１μｍ）
のＸ線（ＣｕＫα）回折像の一例である。Figure 6 shows a silicon thin film (1 μm in film thickness) according to the present invention.
This is an example of an X-ray (CuKα) diffraction image of .
図中の曲線３７は本発明よりなる試料の代表例であり、
５ｉ（１１１）およびＳｉ （２２０）付近にピークが
観測される。このピークの半値幅より結晶粒径を推算す
ると、約１００人程度と計算される。他方、第６図中の
曲線３８は、従来の方法により製造したシリコン薄膜で
あり、曲線３７のようなピークは観測されない。なお、
図中のハローパターンは基板に用いたガラスからのもの
で、非晶質シリコン薄膜からのハローパターンは、膜が
薄いためはっきりとは観測されていない。Curve 37 in the figure is a representative example of a sample made of the present invention,
Peaks are observed near 5i (111) and Si (220). Estimating the crystal grain size from the half width of this peak, it is calculated to be about 100 people. On the other hand, curve 38 in FIG. 6 is a silicon thin film manufactured by the conventional method, and no peak like curve 37 is observed. In addition,
The halo pattern in the figure is from the glass used as the substrate, and the halo pattern from the amorphous silicon thin film is not clearly observed because the film is thin.
以上説明のように、本発明によればドーピング効率が高
（、高電気伝導度を有するＰ型シリコン薄膜またはＮ型
シリコン薄膜を提供でき、その応用範囲はきわめて広く
、特にＰ型シリコン薄膜は、光学的バンドギャップ（光
学的禁制帯幅）をン・
縮めることな（高導電性を有するものが得られるので、
太陽電池等に用いるときわめて有用である。それゆえ、
本発明は電子産業に利用してその効果はすこぶる大きい
。As explained above, according to the present invention, a P-type silicon thin film or an N-type silicon thin film having high doping efficiency (and high electrical conductivity) can be provided, and its application range is extremely wide. without narrowing the optical bandgap (optical forbidden band width).
It is extremely useful when used in solar cells, etc. therefore,
The present invention can be used in the electronic industry with great effect.
第１図は本発明のシリコン薄膜を製造する装置を示す概
略線図、第２〜５図は本発明の、シリコン薄膜の諸特性
を示すグラフ、第６図は本発明のシリコン薄膜のＸ線回
折像を表わす線図である。
２：油回転ポンプ
３：油拡散ポンプ
４ニジランボンベ
５：水素ボンベ
６．７：ドーパントガスボンベ
８：流量計
９：真空容器
Ｏ：メインバルブ
ｌ：真空計
２：高周波発振器
３．１３′：電極
４：ヒータ
５：基 板
１：混合容器
第１図
第３図
Ｂ２Ｈ，／Ｓｉ Ｈ４
ＰＦ、を又はＰＨ３／Ｓ！ Ｈ＆
第５図
ＢｚＨｓ／ＳｉＨ４FIG. 1 is a schematic diagram showing an apparatus for producing a silicon thin film of the present invention, FIGS. 2 to 5 are graphs showing various characteristics of the silicon thin film of the present invention, and FIG. 6 is an X-ray diagram of the silicon thin film of the present invention. It is a line diagram showing a diffraction image. 2: Oil rotary pump 3: Oil diffusion pump 4 Nijiran cylinder 5: Hydrogen cylinder 6.7: Dopant gas cylinder 8: Flow meter 9: Vacuum container O: Main valve l: Vacuum gauge 2: High frequency oscillator 3.13': Electrode 4: Heater 5: Substrate 1: Mixing container Fig. 1 Fig. 3 B2H, /Si H4 PF, or PH3/S! H & Figure 5 BzHs/SiH4
Claims (1)
択された少なくとも一種の元素ならびにリン、ヒ素等の
元素周期律表第Ｖ族の元素の群から選択された少なくと
も一種の元素を含有し、大部分がシリコン原子からなる
シリコン薄膜であって、非晶質層中に微結晶粒が混在し
、該シリコン薄膜の電気伝導度が１０＾−＾１Ω＾−＾
１ｃｍ＾−＾１以上であり、電気伝導度の活性化エネル
ギーが０． ０３１ｅＶ以下であり、光学的バンドギャップ（光学的
禁制帯幅）が１．７ｅＶ以上であり、Ｘ線回折により、
非晶質層中の微結晶部分が約１００Å〜５００Åの範囲
の平均粒径を示すＮ型シリコン薄膜。(1) Contains at least one element selected from the group of fluorine, chlorine, bromine, iodine and hydrogen, and at least one element selected from the group of elements of Group V of the Periodic Table of Elements such as phosphorus and arsenic. , a silicon thin film consisting mostly of silicon atoms, with microcrystalline grains mixed in the amorphous layer, and the electrical conductivity of the silicon thin film is 10^-^1Ω^-^
1cm^-^1 or more, and the activation energy of electrical conductivity is 0. 031 eV or less, the optical band gap (optical forbidden band width) is 1.7 eV or more, and by X-ray diffraction,
An N-type silicon thin film in which the microcrystalline portions in the amorphous layer exhibit an average grain size in the range of about 100 Å to 500 Å.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1220198A JPH02275620A (en) | 1980-10-15 | 1989-08-29 | N-type silicon thin film |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55143010A JPS5767020A (en) | 1980-10-15 | 1980-10-15 | Thin silicon film and its manufacture |
| JP1220198A JPH02275620A (en) | 1980-10-15 | 1989-08-29 | N-type silicon thin film |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP55143010A Division JPS5767020A (en) | 1980-10-15 | 1980-10-15 | Thin silicon film and its manufacture |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02275620A true JPH02275620A (en) | 1990-11-09 |
Family
ID=26474841
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1220198A Pending JPH02275620A (en) | 1980-10-15 | 1989-08-29 | N-type silicon thin film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02275620A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5726461A (en) * | 1995-01-31 | 1998-03-10 | Sharp Kabushiki Kaisha | Active matrix substrate and switching element |
-
1989
- 1989-08-29 JP JP1220198A patent/JPH02275620A/en active Pending
Non-Patent Citations (1)
| Title |
|---|
| JAPAN.J.APPL.PHYS=1980 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5726461A (en) * | 1995-01-31 | 1998-03-10 | Sharp Kabushiki Kaisha | Active matrix substrate and switching element |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPS6356172B2 (en) | ||
| CA1241100A (en) | Solar cell made from amorphous superlattice material | |
| US4459163A (en) | Amorphous semiconductor method | |
| US4491682A (en) | Amorphous silicon photovoltaic device including a two-layer transparent electrode | |
| US5507881A (en) | Thin-film solar cell and method of manufacturing same | |
| US4598304A (en) | Thin film devices of silicon | |
| GB2147316A (en) | A method of making p-doped silicon films and devices made therefrom | |
| IT8224631A1 (en) | A PIU PHOTOVOLTAIC DEVICE! SEMICONDUCTOR LAYERS AND PROCEDURE FOR ITS MANUFACTURING | |
| US4520380A (en) | Amorphous semiconductors equivalent to crystalline semiconductors | |
| JPH07123112B2 (en) | Method for depositing p-type amorphous semiconductor and method for manufacturing photoreceptor for electrophotography | |
| US4604636A (en) | Microcrystalline semiconductor method and devices | |
| US4396793A (en) | Compensated amorphous silicon solar cell | |
| US4710786A (en) | Wide band gap semiconductor alloy material | |
| KR910002764B1 (en) | Amorphous semiconductor method and devices | |
| JP2692091B2 (en) | Silicon carbide semiconductor film and method for manufacturing the same | |
| US4409424A (en) | Compensated amorphous silicon solar cell | |
| JPS6329821B2 (en) | ||
| US4839312A (en) | Fluorinated precursors from which to fabricate amorphous semiconductor material | |
| US4696702A (en) | Method of depositing wide bandgap amorphous semiconductor materials | |
| US4845043A (en) | Method for fabricating photovoltaic device having improved short wavelength photoresponse | |
| JPH02275620A (en) | N-type silicon thin film | |
| JPH02263431A (en) | Manufacture of silicon thin film | |
| JPS6316616A (en) | Silicon thin film and manufacture of the same | |
| JPH03145719A (en) | Silicon thin film and manufacture thereof | |
| JPH03219622A (en) | Silicon thin film and its manufacture |