JPH0997916A - Solar cell and its manufacturing method - Google Patents
Solar cell and its manufacturing methodInfo
- Publication number
- JPH0997916A JPH0997916A JP7307253A JP30725395A JPH0997916A JP H0997916 A JPH0997916 A JP H0997916A JP 7307253 A JP7307253 A JP 7307253A JP 30725395 A JP30725395 A JP 30725395A JP H0997916 A JPH0997916 A JP H0997916A
- Authority
- JP
- Japan
- Prior art keywords
- silicon semiconductor
- layer
- solar cell
- forming
- semiconductor substrate
- 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.)
- Granted
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 20
- 239000004065 semiconductor Substances 0.000 claims abstract description 98
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 73
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 73
- 239000010703 silicon Substances 0.000 claims abstract description 73
- 239000000758 substrate Substances 0.000 claims abstract description 57
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 24
- 229910052814 silicon oxide Inorganic materials 0.000 claims abstract description 24
- 229910021424 microcrystalline silicon Inorganic materials 0.000 claims description 58
- 238000010438 heat treatment Methods 0.000 claims description 26
- 229910052581 Si3N4 Inorganic materials 0.000 claims description 6
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims description 6
- 238000006243 chemical reaction Methods 0.000 abstract description 13
- 230000005684 electric field Effects 0.000 abstract description 9
- 230000001965 increasing effect Effects 0.000 abstract description 7
- 239000013078 crystal Substances 0.000 abstract description 5
- 230000005685 electric field effect Effects 0.000 abstract 1
- 238000009413 insulation Methods 0.000 abstract 1
- 230000005669 field effect Effects 0.000 description 11
- 239000007789 gas Substances 0.000 description 11
- 238000005215 recombination Methods 0.000 description 9
- 230000006798 recombination Effects 0.000 description 9
- 238000000034 method Methods 0.000 description 8
- 239000000969 carrier Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 6
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 238000001259 photo etching Methods 0.000 description 4
- 238000005268 plasma chemical vapour deposition Methods 0.000 description 4
- 229910052709 silver Inorganic materials 0.000 description 3
- 239000010936 titanium Substances 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 229910052796 boron Inorganic materials 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000002019 doping agent Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000001678 irradiating effect Effects 0.000 description 2
- 229910052763 palladium Inorganic materials 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- XHXFXVLFKHQFAL-UHFFFAOYSA-N phosphoryl trichloride Chemical compound ClP(Cl)(Cl)=O XHXFXVLFKHQFAL-UHFFFAOYSA-N 0.000 description 2
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 2
- 229920005591 polysilicon Polymers 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 229910021419 crystalline silicon Inorganic materials 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- RLOWWWKZYUNIDI-UHFFFAOYSA-N phosphinic chloride Chemical compound ClP=O RLOWWWKZYUNIDI-UHFFFAOYSA-N 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000010944 silver (metal) Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- FAQYAMRNWDIXMY-UHFFFAOYSA-N trichloroborane Chemical compound ClB(Cl)Cl FAQYAMRNWDIXMY-UHFFFAOYSA-N 0.000 description 1
- WXRGABKACDFXMG-UHFFFAOYSA-N trimethylborane Chemical compound CB(C)C WXRGABKACDFXMG-UHFFFAOYSA-N 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
- H01L31/06—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by at least one potential-jump barrier or surface barrier
- H01L31/068—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by at least one potential-jump barrier or surface barrier the potential barriers being only of the PN homojunction type, e.g. bulk silicon PN homojunction solar cells or thin film polycrystalline silicon PN homojunction solar cells
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
- H01L31/1804—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof comprising only elements of Group IV of the Periodic System
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
- H01L31/1804—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof comprising only elements of Group IV of the Periodic System
- H01L31/1812—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof comprising only elements of Group IV of the Periodic System including only AIVBIV alloys, e.g. SiGe
- H01L31/1816—Special manufacturing methods for microcrystalline layers, e.g. uc-SiGe, uc-SiC
-
- 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
- Y02E10/547—Monocrystalline silicon PV cells
-
- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、太陽電池に関し、
特に光電変換効率を改善する太陽電池及びその製造方法
に関するものである。The present invention relates to a solar cell,
In particular, the present invention relates to a solar cell that improves photoelectric conversion efficiency and a method for manufacturing the same.
【０００２】[0002]
【従来の技術】従来の太陽電池について、図４に示した
断面構造に基づき説明する。凹凸加工されたＰ型シリコ
ン半導体基板４１の光入射面側には燐（Ｐ）を不純物と
するＮ型シリコン半導体層４２が形成されている。Ｎ型
シリコン半導体層４２の上にはシリコン酸化膜層４３
が、シリコン酸化膜層４３の上には窒化シリコン膜から
なる反射防止膜層４４が形成されている。さらに、シリ
コン酸化膜層４３と反射防止膜層４４を貫通してＮ型シ
リコン半導体層４２に接続されたチタン（Ｔｉ）／パラ
ジウム（Ｐｄ）／銀（Ａｇ）の金属からなるグリッド電
極４５が形成されている。Ｐ型シリコン半導体基板４１
の光入射面側と反対側の裏面上にＰ型シリコン半導体基
板４１と同じ導電型で、かつ、より高濃度にボロン
（Ｂ）を有する水素化微結晶シリコン層（以後、この膜
を「Ｐ+ 型微結晶シリコン層」という）からなる裏面電
界層４７が設けられている。裏面電界層４７上には窒化
シリコン膜からなる絶縁膜層４８が、絶縁膜層４８の上
にはＡｌやＡｇなどの金属からなる裏面電極４９が形成
されている。裏面電極４９は絶縁膜層４８が形成されな
い開口部５０で裏面電界層４７と接続されている。2. Description of the Related Art A conventional solar cell will be described based on the sectional structure shown in FIG. An N-type silicon semiconductor layer 42 containing phosphorus (P) as an impurity is formed on the light-incident surface side of the P-type silicon semiconductor substrate 41 that has been processed to have irregularities. A silicon oxide film layer 43 is formed on the N-type silicon semiconductor layer 42.
However, an antireflection film layer 44 made of a silicon nitride film is formed on the silicon oxide film layer 43. Further, a grid electrode 45 made of a metal of titanium (Ti) / palladium (Pd) / silver (Ag), which penetrates the silicon oxide film layer 43 and the antireflection film layer 44 and is connected to the N-type silicon semiconductor layer 42, is formed. Has been done. P-type silicon semiconductor substrate 41
A hydrogenated microcrystalline silicon layer having the same conductivity type as the P-type silicon semiconductor substrate 41 and having a higher concentration of boron (B) on the back surface opposite to the light incident surface side (hereinafter referred to as "P A back surface electric field layer 47 made of a “ + type microcrystalline silicon layer”) is provided. An insulating film layer 48 made of a silicon nitride film is formed on the back surface electric field layer 47, and a back electrode 49 made of a metal such as Al or Ag is formed on the insulating film layer 48. The back surface electrode 49 is connected to the back surface field layer 47 through the opening 50 where the insulating film layer 48 is not formed.
【０００３】Ｐ+ 型微結晶シリコン層はＰ型シリコン半
導体基板４１よりも高濃度にＢを含み、広い禁制帯幅を
もつことから、裏面電界層４７とＰ型シリコン半導体基
板４１との接合面において内部電界を形成し、裏面近傍
で発生した少数キャリア（電子）をＰ型シリコン半導体
基板４１の内部へ押し戻し、基板裏面でのキャリアの再
結合損失を抑制して光電変換効率を高める働きをしてい
る（以後、この働きを「裏面電界効果」という）。さら
に、絶縁膜層４８はＰ型シリコン半導体基板４１を抜け
て裏面電極４９に達する光が再びＰ型シリコン半導体基
板４１に向かう裏面反射を大きくして、光電変換効率を
高める働きをしている。Since the P + -type microcrystalline silicon layer contains B in a higher concentration than the P-type silicon semiconductor substrate 41 and has a wide band gap, the junction surface between the back surface electric field layer 47 and the P-type silicon semiconductor substrate 41. At the same time, an internal electric field is formed to push back minority carriers (electrons) generated in the vicinity of the back surface to the inside of the P-type silicon semiconductor substrate 41, suppress recombination loss of carriers on the back surface of the substrate, and enhance photoelectric conversion efficiency. (Hereafter, this function is called "back surface field effect"). Further, the insulating film layer 48 has a function of increasing the back surface reflection of the light passing through the P-type silicon semiconductor substrate 41 and reaching the back surface electrode 49 toward the P-type silicon semiconductor substrate 41 again, and increasing the photoelectric conversion efficiency.
【０００４】このＰ+ 型微結晶シリコン層を裏面電界層
４７とした太陽電池の製造方法においては、Ｐ+ 型微結
晶シリコン層上に裏面電極を蒸着形成した後、熱処理を
行っていたが、特開平６−３１０７４０号公報で開示さ
れたように、良好な光電変換効率が得られる最適温度範
囲は２００〜３００℃であった。In the method of manufacturing a solar cell in which the P + -type microcrystalline silicon layer is used as the back surface electric field layer 47, the back surface electrode is vapor-deposited on the P + -type microcrystalline silicon layer, and then heat treatment is performed. As disclosed in JP-A-6-310740, the optimum temperature range in which good photoelectric conversion efficiency is obtained was 200 to 300 ° C.
【０００５】[0005]
【発明が解決しようとする課題】Ｐ型シリコン半導体基
板上に形成した高濃度にドーパントを含むＰ+ 型微結晶
シリコン層は、熱処理温度の上昇に伴い比抵抗値が小さ
くなって、裏面電界層としての品質が向上する。In the P + type microcrystalline silicon layer formed on the P type silicon semiconductor substrate and containing a high concentration of dopant, the specific resistance value becomes smaller as the heat treatment temperature increases, and the back surface electric field layer is formed. As the quality is improved.
【０００６】ところが、特開平６−３１０７４０号公報
で開示されたように、従来の太陽電池においては、３０
０℃以上で熱処理を行うと光電変換効率が低下してしま
い、熱処理によるＰ+ 型微結晶シリコン層の品質向上が
十分に活用されていなかった。However, as disclosed in Japanese Unexamined Patent Publication No. 6-310740, in the conventional solar cell, 30
When the heat treatment is performed at 0 ° C. or higher, the photoelectric conversion efficiency is reduced, and the quality improvement of the P + -type microcrystalline silicon layer due to the heat treatment has not been fully utilized.
【０００７】この光電変換効率の低下の原因は、熱処理
によって、裏面電極と接する領域のＰ+ 型微結晶シリコ
ン層がＰ型シリコン半導体基板の裏面にキャリアの再結
合損失が大きい領域を形成して、裏面電界効果を低下さ
せることにあることが判明した。以下にその詳細を述べ
る。つまり、絶縁膜層によってＰ+ 型微結晶シリコン層
が裏面電極から離されたＰ型シリコン半導体基板裏面上
の領域での熱処理の影響と、Ｐ+ 型微結晶シリコン層が
裏面電極と接するＰ型シリコン半導体基板裏面上の領域
での熱処理の影響とは異なっている。まず、前者の領域
では、熱処理温度の上昇に伴いＰ+ 型微結晶シリコン層
の比抵抗値が小さくなり、Ｐ型シリコン半導体基板裏面
でのキャリア再結合損失を抑制する裏面電界効果が向上
する。一方、後者の領域では、熱処理によってＰ+ 型微
結晶シリコン層が裏面電極と反応して変質する。熱処理
温度が高いほど変質の程度が大きくなり、変質したＰ+
型微結晶シリコン層と接するＰ型シリコン半導体基板の
裏面でのキャリアの再結合損失を増大する。３００℃以
上の熱処理では、前者の領域での裏面電界効果の向上
を、後者の領域での再結合損失の増大が打ち消すことに
よって、裏面電界効果を低下させることになるものと思
われる。The cause of this decrease in photoelectric conversion efficiency is that the P + -type microcrystalline silicon layer in the region in contact with the back electrode forms a region on the back face of the P-type silicon semiconductor substrate where the carrier recombination loss is large by heat treatment. , It was found that it is to reduce the back surface field effect. The details will be described below. That is, the influence of heat treatment in the region on the back surface of the P-type silicon semiconductor substrate where the P + -type microcrystalline silicon layer is separated from the back electrode by the insulating film layer, and the P-type in which the P + -type microcrystalline silicon layer is in contact with the back electrode. This is different from the effect of heat treatment in the region on the back surface of the silicon semiconductor substrate. First, in the former region, the specific resistance value of the P + -type microcrystalline silicon layer decreases as the heat treatment temperature increases, and the back surface field effect of suppressing carrier recombination loss on the back surface of the P-type silicon semiconductor substrate is improved. On the other hand, in the latter region, the heat treatment causes the P + -type microcrystalline silicon layer to react with the back surface electrode and deteriorate. The higher the heat treatment temperature, the greater the degree of alteration, and the altered P +
The recombination loss of carriers on the back surface of the P-type silicon semiconductor substrate in contact with the type microcrystalline silicon layer is increased. It is considered that the heat treatment at 300 ° C. or higher reduces the back surface field effect by canceling the increase in the back surface field effect in the former area and the increase in the recombination loss in the latter area.
【０００８】そこで、本発明の目的は、３００℃以上の
高温での熱処理によっても、裏面電界効果が向上して、
高い光電変換効率が得られる太陽電池とその製造方法を
提供することにある。Therefore, the object of the present invention is to improve the back surface field effect even by heat treatment at a high temperature of 300 ° C. or higher,
It is intended to provide a solar cell that can obtain high photoelectric conversion efficiency and a method for manufacturing the same.
【０００９】[0009]
【課題を解決するための手段】本発明の太陽電池は、光
入射側の第１導電型のシリコン半導体基板上に第２導電
型のシリコン半導体層が設けられ、光入射側と反対側の
上記シリコン半導体基板上に第１絶縁層が所定領域のみ
に設けられ、上記シリコン半導体基板より高濃度の第１
導電型の微結晶シリコン半導体層が上記所定領域を覆う
ように設けられ、上記所定領域に対応する開口部を有す
る第２絶縁層が上記微結晶シリコン半導体層上に設けら
れ、裏面電極が上記開口部を覆うように設けられ上記微
結晶シリコン半導体層と導通することを特徴とする。In the solar cell of the present invention, a second-conductivity-type silicon semiconductor layer is provided on the first-conductivity-type silicon semiconductor substrate on the light-incident side, and the second-conductivity-type silicon semiconductor layer is provided on the opposite side to the light-incident side. The first insulating layer is provided only on a predetermined region on the silicon semiconductor substrate, and the first insulating layer has a concentration higher than that of the silicon semiconductor substrate.
A conductive type microcrystalline silicon semiconductor layer is provided so as to cover the predetermined region, a second insulating layer having an opening corresponding to the predetermined region is provided on the microcrystalline silicon semiconductor layer, and a back electrode is formed in the opening. It is provided so as to cover the portion and is electrically connected to the microcrystalline silicon semiconductor layer.
【００１０】つまり、裏面電極と接続される領域の微結
晶シリコン半導体層は、第１絶縁層によってシリコン半
導体基板と離れているため、熱処理により変質してもシ
リコン半導体基板の裏面には直接影響を与えない。すな
わち、熱処理によって裏面電極と接する領域の微結晶シ
リコン半導体層がシリコン半導体基板の裏面にキャリア
の再結合損失が大きい領域を形成しない。That is, since the microcrystalline silicon semiconductor layer in the region connected to the back surface electrode is separated from the silicon semiconductor substrate by the first insulating layer, even if it is deteriorated by heat treatment, the back surface of the silicon semiconductor substrate is not directly affected. Do not give. That is, the heat treatment does not form an area where the recombination loss of carriers is large in the back surface of the silicon semiconductor substrate in the microcrystalline silicon semiconductor layer in the area in contact with the back electrode.
【００１１】また、第１導電型であって上記微結晶シリ
コン半導体層より低抵抗の層が、上記開口部に対応して
上記微結晶シリコン半導体層に設けられると共に上記裏
面電極に接続されていることを特徴とする。A layer of the first conductivity type having a resistance lower than that of the microcrystalline silicon semiconductor layer is provided in the microcrystalline silicon semiconductor layer corresponding to the opening and is connected to the back electrode. It is characterized by
【００１２】つまり、上記微結晶シリコン半導体層を介
して取り出す電流が開口部に集中しても、第１導電型の
低抵抗の層を設けているため、太陽電池の曲線因子の低
下が抑制され、さらに光電変換効率を高めることができ
る。That is, even if the current taken out through the microcrystalline silicon semiconductor layer is concentrated in the opening, the reduction of the fill factor of the solar cell is suppressed because the low resistance layer of the first conductivity type is provided. Moreover, the photoelectric conversion efficiency can be further increased.
【００１３】また、第１絶縁層が、酸化シリコン膜であ
ることを特徴とする。The first insulating layer is a silicon oxide film.
【００１４】つまり、第１絶縁層はパッシベーション効
果の高い酸化シリコン膜で形成されることにより、シリ
コン半導体基板の絶縁層との界面でのキャリアの再結合
損失を抑える事ができ、製造工程での整合性もよい。な
お、第１絶縁膜に窒化シリコン膜を用いることもでき
る。That is, since the first insulating layer is formed of a silicon oxide film having a high passivation effect, it is possible to suppress the recombination loss of carriers at the interface with the insulating layer of the silicon semiconductor substrate, and it is possible to suppress the recombination loss. Good consistency. Note that a silicon nitride film can be used as the first insulating film.
【００１５】本発明の太陽電池の製造方法は、第１導電
型のシリコン半導体基板の一方面上に第２導電型のシリ
コン半導体層を形成する工程と、上記シリコン半導体基
板の他方面上の所定領域のみに第１絶縁層を形成する工
程と、上記所定領域を覆うように上記シリコン半導体基
板より高濃度の第１導電型微結晶シリコン半導体層を形
成する工程と、上記微結晶シリコン半導体層上に第２絶
縁層を形成する工程と、上記所定領域に対応して第２絶
縁層に開口部を形成する工程と、上記開口部を覆うよう
に裏面電極を形成して上記第１導電型微結晶シリコン半
導体層と接続する工程と、裏面電極形成後に３００〜４
００℃の熱処理を行う工程と、を含むことを特徴とす
る。A method of manufacturing a solar cell according to the present invention comprises a step of forming a second conductivity type silicon semiconductor layer on one surface of a first conductivity type silicon semiconductor substrate, and a predetermined step on the other surface of the silicon semiconductor substrate. Forming a first insulating layer only on the region; forming a first conductive type microcrystalline silicon semiconductor layer having a higher concentration than the silicon semiconductor substrate so as to cover the predetermined region; and on the microcrystalline silicon semiconductor layer. A step of forming a second insulating layer on the first insulating layer, a step of forming an opening in the second insulating layer corresponding to the predetermined region, and forming a back electrode to cover the opening to form the first conductive type fine layer. Step of connecting to the crystalline silicon semiconductor layer and 300 to 4 after forming the back surface electrode
And a step of performing heat treatment at 00 ° C.
【００１６】本発明の太陽電池の製造方法によれば、熱
処理温度を上昇させることができ、第１絶縁層によって
裏面電極と離された所定領域上の周辺の微結晶シリコン
半導体層の品質向上によって、裏面電界効果を高める事
ができる。According to the method of manufacturing a solar cell of the present invention, the heat treatment temperature can be raised, and the quality of the peripheral microcrystalline silicon semiconductor layer on a predetermined region separated from the back electrode by the first insulating layer can be improved. The back surface field effect can be enhanced.
【００１７】さらに、本発明の太陽電池の製造方法は、
第１導電型のシリコン半導体基板の一方面上に第２導電
型のシリコン半導体層を形成する工程と、上記シリコン
半導体基板の他方面上の所定領域のみに第１絶縁層を形
成する工程と、上記所定領域を覆うように上記シリコン
半導体基板より高濃度の第１導電型微結晶シリコン半導
体層を形成する工程と、上記微結晶シリコン半導体層上
に第２絶縁層を形成する工程と、上記所定領域に対応し
て第２絶縁層に開口部を形成する工程と、第１導電型で
あって上記微結晶シリコン半導体層より低抵抗の層を上
記微結晶シリコン半導体層に上記開口部に対応させて形
成する工程と、上記開口部を覆うように裏面電極を形成
して上記低抵抗の層と接続する工程と、裏面電極形成後
に３００〜４００℃の熱処理を行う工程と、を含むこと
を特徴とする。Furthermore, the method of manufacturing the solar cell of the present invention comprises:
A step of forming a second conductivity type silicon semiconductor layer on one surface of the first conductivity type silicon semiconductor substrate, and a step of forming a first insulating layer only in a predetermined region on the other surface of the silicon semiconductor substrate, Forming a first conductive type microcrystalline silicon semiconductor layer having a higher concentration than the silicon semiconductor substrate so as to cover the predetermined region; forming a second insulating layer on the microcrystalline silicon semiconductor layer; A step of forming an opening in the second insulating layer corresponding to the region; and a layer of the first conductivity type having a resistance lower than that of the microcrystalline silicon semiconductor layer is caused to correspond to the opening in the microcrystalline silicon semiconductor layer. And a step of forming a back surface electrode so as to cover the opening and connecting to the low resistance layer, and a step of performing heat treatment at 300 to 400 ° C. after forming the back surface electrode. And
【００１８】本発明の太陽電池の製造方法によれば、熱
処理温度を上昇させることができ、第１絶縁層によって
裏面電極と離された所定領域上の周辺の微結晶シリコン
半導体層の品質向上によって、裏面電界効果を高める事
ができる上に、開口部の抵抗を低くできるので、太陽電
池の曲線因子の低下を抑制できる。According to the method of manufacturing a solar cell of the present invention, the heat treatment temperature can be raised, and the quality of the peripheral microcrystalline silicon semiconductor layer on the predetermined region separated from the back electrode by the first insulating layer can be improved. Since the back surface field effect can be enhanced and the resistance of the opening can be reduced, it is possible to suppress the reduction of the fill factor of the solar cell.
【００１９】[0019]
【発明の実施の形態】本発明に係る太陽電池とその製造
方法を実施例に基づき以下に説明する。BEST MODE FOR CARRYING OUT THE INVENTION A solar cell according to the present invention and a method for manufacturing the same will be described below based on Examples.
【００２０】図１に、本発明の実施例に係る太陽電池の
断面構造を示す。ここでＰ型シリコン半導体基板１１の
光入射面側にＮ型シリコン半導体層１２が形成されてい
る。Ｎ型シリコン半導体層１２の表面は、入射光の反射
を低減するために凹凸にされている。Ｎ型シリコン半導
体層１２はシリコン酸化膜層１３によって覆われてお
り、シリコン酸化膜層１３は反射防止膜層１４によって
覆われている。光照射により発生した表面からの電流
は、シリコン酸化膜層１３と反射防止膜層１４を貫通し
てＮ型シリコン半導体層１２に接続されたグリッド電極
１５を介して取り出される。Ｐ型シリコン半導体基板１
１の光入射面側と反対側の裏面上には、部分的にシリコ
ン酸化膜１６が形成されている。Ｐ型シリコン半導体基
板１１とシリコン酸化膜１６を覆うように、基板と同じ
Ｐ型の不純物が高濃度に添加された裏面電界層を形成す
るＰ+ 型微結晶シリコン層１７が形成されている。Ｐ+
型微結晶シリコン層１７は絶縁膜層１８によって覆われ
ており、絶縁膜層１８は裏面電極１９によって覆われて
いる。裏面電極１９は、シリコン酸化膜１６が形成され
ている領域２０の内部に設けられ絶縁膜層１８の無い開
口部２１でＰ+ 型微結晶シリコン層１７と接続されてい
る。裏面からの電流はこの裏面電極１９を介して取り出
される。FIG. 1 shows a sectional structure of a solar cell according to an embodiment of the present invention. Here, the N-type silicon semiconductor layer 12 is formed on the light incident surface side of the P-type silicon semiconductor substrate 11. The surface of the N-type silicon semiconductor layer 12 is made uneven so as to reduce reflection of incident light. The N-type silicon semiconductor layer 12 is covered with a silicon oxide film layer 13, and the silicon oxide film layer 13 is covered with an antireflection film layer 14. The current generated from the surface by the light irradiation is taken out through the grid electrode 15 which penetrates the silicon oxide film layer 13 and the antireflection film layer 14 and is connected to the N-type silicon semiconductor layer 12. P-type silicon semiconductor substrate 1
A silicon oxide film 16 is partially formed on the back surface opposite to the light incident surface side of 1. A P + -type microcrystalline silicon layer 17 is formed so as to cover the P-type silicon semiconductor substrate 11 and the silicon oxide film 16 and form a back surface electric field layer in which the same P-type impurities as the substrate are added at a high concentration. P +
The microcrystalline silicon layer 17 is covered with an insulating film layer 18, and the insulating film layer 18 is covered with a back surface electrode 19. The back electrode 19 is connected to the P + -type microcrystalline silicon layer 17 through an opening 21 provided inside the region 20 where the silicon oxide film 16 is formed and having no insulating film layer 18. The current from the back surface is taken out through the back surface electrode 19.
【００２１】次に、上記太陽電池の製造方法について、
図２に基づき説明する。図２は、上記太陽電池の製造フ
ローを示す図である。Next, with respect to the method for manufacturing the above solar cell,
A description will be given based on FIG. FIG. 2 is a diagram showing a manufacturing flow of the solar cell.
【００２２】まず、単結晶のＰ型シリコン半導体基板１
１（１００ｍｍφ，３００μｍ厚、比抵抗：数Ω−ｃ
ｍ）を洗浄した後、表面が凹凸になるように異方性エッ
チングを行った（ステップＳ１）。ここで、単結晶のＰ
型シリコン半導体基板の替わりに、多結晶のＰ型シリコ
ン半導体基板を用いることもできる。この場合の表面凹
凸形成は、レーザを用いて溝を掘ったり、機械的に溝を
掘る方法により行う。First, a single crystal P-type silicon semiconductor substrate 1
1 (100 mmφ, 300 μm thickness, specific resistance: several Ω-c
After cleaning m), anisotropic etching was performed so that the surface becomes uneven (step S1). Where single crystal P
Instead of the type silicon semiconductor substrate, a polycrystalline P type silicon semiconductor substrate can also be used. In this case, the surface unevenness is formed by digging a groove with a laser or by mechanically digging a groove.
【００２３】次に、オキシ塩化燐（ＰＯＣｌ3） を用い
た気相拡散によって燐（Ｐ）をＰ型シリコン半導体基板
１１の表面に拡散してＮ型シリコン半導体層１２を形成
しＰＮ接合を形成した（ステップＳ２）。続いて、光入
射面と反対側のＰ型シリコン半導体基板１１の裏面側を
硝酸とフッ酸の混合液を用いてエッチングして、裏面側
に形成されているＮ型シリコン半導体層１２を除去した
（ステップＳ３）。続いて、熱酸化により入射面側のシ
リコン酸化膜層１３と裏面側全面のシリコン酸化膜１６
とを同時に形成した（ステップＳ４）。さらに、光入射
側に窒化シリコン膜からなる反射防止膜層１４をプラズ
マＣＶＤ法により形成した。Next, phosphorus (P) is diffused on the surface of the P-type silicon semiconductor substrate 11 by vapor phase diffusion using phosphorus oxychloride (POCl 3 ) to form an N-type silicon semiconductor layer 12 and form a PN junction. (Step S2). Then, the back surface side of the P-type silicon semiconductor substrate 11 opposite to the light incident surface was etched using a mixed solution of nitric acid and hydrofluoric acid to remove the N-type silicon semiconductor layer 12 formed on the back surface side. (Step S3). Subsequently, the silicon oxide film layer 13 on the incident surface side and the silicon oxide film 16 on the entire back surface side are thermally oxidized.
And were simultaneously formed (step S4). Further, an antireflection film layer 14 made of a silicon nitride film was formed on the light incident side by a plasma CVD method.
【００２４】次に、フォトエッチング法を用いて、裏面
側のシリコン酸化膜１６のパターニングを行い、後にＰ
+ 型微結晶シリコン層１７と裏面電極１９とが接続され
る予定の開口部２１を含む領域２０にシリコン酸化膜１
６を形成した（ステップＳ５）。領域２０に形成された
シリコン酸化膜１６は、Ｐ型シリコン半導体基板１１と
後に形成されるＰ+ 型微結晶シリコン層１７とを部分的
に分離する絶縁層となり、領域２０のＰ型シリコン半導
体基板１１の絶縁層の再結合損失を低減して、領域２０
以外のＰ+ 型微結晶シリコン層１７とＰ型シリコン半導
体基板１１の界面での裏面電界効果を高める働きに優れ
ており、最適である。Next, the silicon oxide film 16 on the back surface side is patterned by using a photo-etching method, and then P
The silicon oxide film 1 is formed in the region 20 including the opening 21 where the + type microcrystalline silicon layer 17 and the back surface electrode 19 are to be connected.
6 was formed (step S5). The silicon oxide film 16 formed in the region 20 serves as an insulating layer for partially separating the P-type silicon semiconductor substrate 11 and the P + -type microcrystalline silicon layer 17 to be formed later, and the P-type silicon semiconductor substrate in the region 20 is formed. 11 to reduce the recombination loss of the insulating layer,
Other than the above, it has an excellent function of enhancing the back surface field effect at the interface between the P + type microcrystalline silicon layer 17 and the P type silicon semiconductor substrate 11, and is optimal.
【００２５】次に、プラズマＣＶＤ法により、Ｐ+ 型微
結晶シリコン層１７を膜厚２００ｎｍでＰ型シリコン半
導体基板１１の裏面とシリコン酸化膜層１６とを覆って
形成した（ステップＳ６）。上記プラズマＣＶＤ法によ
るＰ+ 型微結晶シリコン層１７の形成条件として、例え
ば、ガス種はＳｉＨ4 （またはＳｉ2Ｈ6）とＢ2Ｈ6の混
合ガス、ガス流量比はＨ2／ＳｉＨ4＝１５０、Ｂ2Ｈ6／
ＳｉＨ4＝０．０１、ガス圧力は２０Ｐａ、基板温度は
１５０℃、ＲＦパワーは１００Ｗ（１３．５６ＭＨｚ）
である。Next, a P + type microcrystalline silicon layer 17 having a film thickness of 200 nm was formed by plasma CVD so as to cover the back surface of the P type silicon semiconductor substrate 11 and the silicon oxide film layer 16 (step S6). As conditions for forming the P + -type microcrystalline silicon layer 17 by the plasma CVD method, for example, the gas species is a mixed gas of SiH 4 (or Si 2 H 6 ) and B 2 H 6 , and the gas flow rate ratio is H 2 / SiH 4. = 150, B 2 H 6 /
SiH 4 = 0.01, gas pressure 20 Pa, substrate temperature 150 ° C., RF power 100 W (13.56 MHz)
It is.
【００２６】次に、プラズマＣＶＤ法により、窒化シリ
コン膜からなる絶縁膜層１８を膜厚２００ｎｍでＰ+ 型
微結晶シリコン層１７上に形成する（ステップＳ７）。
続いて、フォトエッチング法を用いて、絶縁膜層１８の
パターニングを行い（ステップＳ８）、微結晶シリコン
層１７と裏面電極１９が接続される開口部２１を開口し
てから、真空蒸着法でＡｌを裏面全面に蒸着し、裏面電
極１９を形成する（ステップＳ９）。Next, the insulating film layer 18 made of a silicon nitride film is formed on the P + -type microcrystalline silicon layer 17 with a film thickness of 200 nm by the plasma CVD method (step S7).
Subsequently, the insulating film layer 18 is patterned by using a photo-etching method (step S8), an opening portion 21 for connecting the microcrystalline silicon layer 17 and the back surface electrode 19 is opened, and then Al is formed by a vacuum evaporation method. Is vapor-deposited on the entire back surface to form a back surface electrode 19 (step S9).
【００２７】次に、フォトエッチング法を用いて光入射
側のシリコン酸化膜層１３及び反射防止膜層１４を開口
して、Ｔｉ，Ｐｄ，Ａｇの順に金属を蒸着により堆積し
て、リフトオフ法により、グリッド電極１５を形成する
（ステップＳ１０）。Next, the photo-etching method is used to open the silicon oxide film layer 13 and the antireflection film layer 14 on the light incident side, a metal is deposited in order of Ti, Pd, and Ag by vapor deposition, and the lift-off method is used. , The grid electrode 15 is formed (step S10).
【００２８】最後に、水素（Ｈ2） ガス雰囲気中で熱処
理を行い（ステップＳ１１）、太陽電池は完成する。本
実施例においては熱処理による太陽電池の特性変化を調
べるため、２００℃，３００℃，４００℃，５００℃の
４通りの温度で、各々１０分間の熱処理を行った。雰囲
気は、窒素（Ｎ2）ガス、水素（Ｈ2）ガス、アルゴン
（Ａｒ）ガスあるいはこれらの混合ガスが適当である。Finally, heat treatment is performed in a hydrogen (H 2 ) gas atmosphere (step S11) to complete the solar cell. In this example, in order to examine the characteristic change of the solar cell due to the heat treatment, heat treatment was performed for 10 minutes at each of four temperatures of 200 ° C, 300 ° C, 400 ° C and 500 ° C. The atmosphere is preferably nitrogen (N 2 ) gas, hydrogen (H 2 ) gas, argon (Ar) gas or a mixed gas thereof.
【００２９】上記製造方法により作製した本発明の太陽
電池と、図４に示した従来構造の太陽電池（構造上、裏
面のシリコン酸化膜がない点と、熱処理温度を２５０℃
とした点が異なり、他の製造条件が本発明と同じ）と
を、ＡＭ１．５のスペクトルで１００ｍＷ／ｃｍ2 の光
のもとで電流―電圧特性を測定したところ、本発明の太
陽電池は３００℃と４００℃で熱処理したものが、従来
の太陽電池より高い光電変換効率が得られた。また、図
３には、４００℃で熱処理した本発明の太陽電池の内部
収集効率（実線）と、Ｈ2 ガス中で２５０℃、１０分の
熱処理をした図４に示した従来の太陽電池の内部収集効
率（破線）とを比較して示す。本発明の太陽電池は、裏
面電界効果の向上により波長１０００ｎｍ以上の長波長
の光が有効に光電変換されていることが判る。なお、内
部収集効率は、短絡状態の太陽電池で光電変換されて出
力される短絡電流について、照射光の波長毎に吸収した
フォトン数に対して出力されるキャリア数（出力電流を
単位電荷で割った値）の比率を示す。The solar cell of the present invention manufactured by the above manufacturing method and the solar cell of the conventional structure shown in FIG. 4 (the structure has no silicon oxide film on the back surface, and the heat treatment temperature is 250 ° C.
And other manufacturing conditions are the same as those of the present invention), and the current-voltage characteristics were measured under the light of 100 mW / cm 2 in the spectrum of AM1.5. The ones heat-treated at 300 ° C. and 400 ° C. had higher photoelectric conversion efficiency than the conventional solar cells. 3 shows the internal collection efficiency (solid line) of the solar cell of the present invention heat-treated at 400 ° C., and the conventional solar cell shown in FIG. 4 heat-treated at 250 ° C. for 10 minutes in H 2 gas. The internal collection efficiency (broken line) is shown for comparison. It can be seen that the solar cell of the present invention effectively photoelectrically converts light having a long wavelength of 1000 nm or more due to the improvement of the back surface field effect. The internal collection efficiency is defined as the number of carriers output (the output current divided by the unit charge) with respect to the number of photons absorbed for each wavelength of the irradiation light in the short-circuit current photoelectrically converted and output by the solar cell in the short-circuited state. Value).
【００３０】図５に、本発明の他の実施例に係る太陽電
池の断面構造を示す。図１と同一部材には同一符号を付
し、説明は省略する。図１の太陽電池と異なる点は、Ｐ
+ 型微結晶シリコン層１７内で開口部２１近傍に、Ｐ+
型微結晶シリコン層１７よりも低抵抗の層２２が形成さ
れており、低抵抗の層２２は裏面金属１９に電気的に接
続されている。FIG. 5 shows a sectional structure of a solar cell according to another embodiment of the present invention. The same members as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. The difference from the solar cell of FIG. 1 is P
In the + type microcrystalline silicon layer 17, P + is formed in the vicinity of the opening 21.
A layer 22 having a lower resistance than the type microcrystalline silicon layer 17 is formed, and the low resistance layer 22 is electrically connected to the back surface metal 19.
【００３１】次に、上記太陽電池の製造方法は、図２に
示した製造フローにおいて、ステップＳ８とステップＳ
９との間にさらに別の工程を導入したものである。つま
り、開口部２１を形成した後に、Ｐ+ 型微結晶シリコン
層１７の開口部２１に、レーザ光を照射することによ
り、その部分をポリシリコン化することにより、Ｐ+ 型
ポリシリコンの低抵抗の層２２を得たものである。ここ
で、低抵抗の層２２を形成するのにレーザ光を用いてい
るので、フォトエッチ工程が不要で、工程が簡略化で
き、コストを下げることできる。レーザ光としては、Ａ
ｒＦエキシマレーザ（波長：１９５ｎｍ）、ＫｒＦエキ
シマレーザ（波長：２４８ｎｍ）、ＸｅＣｌエキシマレ
ーザ（波長：３０８ｎｍ）等が使用できる。照射レーザ
光量は、５００ｍＪ／ｃｍ2としたが、これに限られる
ものではない。なお、レーザ光を照射する際に、光量を
少なくして、低抵抗の層２２を、Ｐ+型微結晶シリコン
層としてもよい。Next, in the manufacturing method of the above-mentioned solar cell, in the manufacturing flow shown in FIG. 2, step S8 and step S8 are performed.
It is the one in which another step is introduced between the first and second steps. In other words, after the opening 21 is formed, the opening 21 of the P + -type microcrystalline silicon layer 17 is irradiated with a laser beam to convert the portion into polysilicon, thereby reducing the resistance of the P + -type polysilicon. The layer 22 of is obtained. Here, since laser light is used to form the low-resistance layer 22, a photo-etching step is not necessary, the steps can be simplified, and the cost can be reduced. The laser light is A
An rF excimer laser (wavelength: 195 nm), a KrF excimer laser (wavelength: 248 nm), a XeCl excimer laser (wavelength: 308 nm), or the like can be used. The irradiation laser light amount was set to 500 mJ / cm 2 , but it is not limited to this. Note that when the laser light is emitted, the light amount may be reduced and the low-resistance layer 22 may be a P + -type microcrystalline silicon layer.
【００３２】また、レーザ光を照射する雰囲気に、３塩
化ボロン（ＢＣｌ3）、トリメチルボロン（Ｂ（ＣＨ3）
3）、ジボラン等のＰ型のドーパントガスを加えておけ
ば、より低抵抗の層２２が得られ、正孔を効率よく導出
することができる。Further, in the atmosphere for irradiating the laser beam, boron trichloride (BCl 3 ), trimethylboron (B (CH 3 ))
3 ), if a P-type dopant gas such as diborane is added, a layer 22 having a lower resistance can be obtained, and holes can be efficiently led out.
【００３３】なお、レーザ光を絶縁膜層１８上からＰ+
型微結晶シリコン層１７に照射して低抵抗の層２２を形
成した後で開口部２１を開口することも可能である。The laser light is emitted from above the insulating film layer 18 to P +
It is also possible to form the low-resistance layer 22 by irradiating the type microcrystalline silicon layer 17 and then open the opening 21.
【００３４】以上の実施例では、Ｐ型シリコン半導体基
板を用いた場合について説明したが、Ｎ型シリコン基板
を用いた場合にも適用できる。その場合、Ｎ型シリコン
基板の光入射側に拡散される不純物はＰ型のボロン
（Ｂ）などであり、裏面電界層である微結晶シリコン層
はＮ型の不純物を高濃度に添加されたものが用いられ
る。In the above embodiments, the case of using the P-type silicon semiconductor substrate has been described, but the present invention can be applied to the case of using the N-type silicon substrate. In that case, the impurity diffused to the light incident side of the N-type silicon substrate is P-type boron (B) or the like, and the microcrystalline silicon layer which is the back surface electric field layer is a high-concentration N-type impurity. Is used.
【００３５】[0035]
【発明の効果】本発明によれば、太陽電池の裏面電界効
果をより向上できるので、光電変換効率を高めることが
できる。According to the present invention, the back surface field effect of the solar cell can be further improved, so that the photoelectric conversion efficiency can be increased.
【００３６】また、太陽電池の曲線因子を向上できるの
で、さらに光電変換効率を高めることができる。Further, since the fill factor of the solar cell can be improved, the photoelectric conversion efficiency can be further improved.
【００３７】また、製造工程の熱処理を高温にできるた
め、製造工程上の熱処理マージンを増加させることがで
きる。Since the heat treatment in the manufacturing process can be performed at a high temperature, the heat treatment margin in the manufacturing process can be increased.
【図１】本発明の実施例の太陽電池の断面構造を示す図
である。FIG. 1 is a diagram showing a cross-sectional structure of a solar cell according to an example of the present invention.
【図２】本発明の実施例の太陽電池の製造フローを示す
図である。FIG. 2 is a diagram showing a manufacturing flow of a solar cell according to an example of the present invention.
【図３】本発明の太陽電池の内部収集効率の波長依存性
を示す図である。FIG. 3 is a diagram showing wavelength dependence of internal collection efficiency of the solar cell of the present invention.
【図４】従来の太陽電池の断面構造を示す図である。FIG. 4 is a diagram showing a cross-sectional structure of a conventional solar cell.
【図５】本発明の他の実施例の太陽電池の断面構造を示
す図である。FIG. 5 is a diagram showing a cross-sectional structure of a solar cell according to another embodiment of the present invention.
１１ Ｐ型シリコン半導体基板 １２ Ｎ型シリコン半導体層 １３ シリコン酸化膜層 １４ 反射防止膜層 １５ グリッド電極 １６ シリコン酸化膜 １７ Ｐ+ 型微結晶シリコン層 １８ 絶縁膜層 １９ 裏面電極 ２０ シリコン酸化膜１６が形成された領域 ２１ 開口部 ２２ 低抵抗の層11 P-type silicon semiconductor substrate 12 N-type silicon semiconductor layer 13 Silicon oxide film layer 14 Antireflection film layer 15 Grid electrode 16 Silicon oxide film 17 P + type microcrystalline silicon layer 18 Insulating film layer 19 Backside electrode 20 Silicon oxide film 16 Formed area 21 Opening 22 Low resistance layer
フロントページの続き (72)発明者 山嵜 一郎 大阪府大阪市阿倍野区長池町22番22号 シ ャープ株式会社内 (72)発明者 小松 雄爾 大阪府大阪市阿倍野区長池町22番22号 シ ャープ株式会社内 (72)発明者 南森 孝幸 大阪府大阪市阿倍野区長池町22番22号 シ ャープ株式会社内Front page continuation (72) Inventor Ichiro Yamazaki, 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Prefecture Sharp Co., Ltd. (72) Yuji Komatsu 22-22, Nagaike-cho, Abeno-ku, Osaka, Osaka Sharp Corporation (72) Inventor Takayuki Minamimori 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka
Claims (5)
基板上に第２導電型のシリコン半導体層が設けられ、 光入射側と反対側の上記シリコン半導体基板上に第１絶
縁層が所定領域のみに設けられ、 上記シリコン半導体基板より高濃度の第１導電型の微結
晶シリコン半導体層が上記所定領域を覆うように設けら
れ、 上記所定領域に対応する開口部を有する第２絶縁層が上
記微結晶シリコン半導体層上に設けられ、 裏面電極が上記開口部を覆うように設けられ上記微結晶
シリコン半導体層と導通することを特徴とする太陽電
池。1. A second-conductivity-type silicon semiconductor layer is provided on a first-conductivity-type silicon semiconductor substrate on the light-incident side, and a first insulating layer is provided on the silicon-semiconductor substrate opposite to the light-incident side. A second insulating layer which is provided only in the region, is provided so as to cover the predetermined region with a first-conductivity-type microcrystalline silicon semiconductor layer having a higher concentration than the silicon semiconductor substrate, and has an opening corresponding to the predetermined region. A solar cell provided on the microcrystalline silicon semiconductor layer, wherein a back electrode is provided so as to cover the opening and electrically connected to the microcrystalline silicon semiconductor layer.
半導体層より低抵抗の層が、上記開口部に対応して上記
微結晶シリコン半導体層に設けられると共に上記裏面電
極に接続されていることを特徴とする請求項１に記載の
太陽電池。2. A layer of the first conductivity type having a resistance lower than that of the microcrystalline silicon semiconductor layer is provided in the microcrystalline silicon semiconductor layer corresponding to the opening and is connected to the back electrode. The solar cell according to claim 1, wherein the solar cell is a solar cell.
リコン膜のいづれかであることを特徴とする請求項１，
２に記載の太陽電池。3. The first insulating layer is either a silicon oxide film or a silicon nitride film.
The solar cell according to 2.
面上に第２導電型のシリコン半導体層を形成する工程
と、 上記シリコン半導体基板の他方面上の所定領域のみに第
１絶縁層を形成する工程と、 上記所定領域を覆うように上記シリコン半導体基板より
高濃度の第１導電型微結晶シリコン半導体層を形成する
工程と、 上記微結晶シリコン半導体層上に第２絶縁層を形成する
工程と、 上記所定領域に対応して第２絶縁層に開口部を形成する
工程と、 上記開口部を覆うように裏面電極を形成して上記第１導
電型微結晶シリコン半導体層と接続する工程と、 裏面電極形成後に３００〜４００℃の熱処理を行う工程
と、を含むことを特徴とする太陽電池の製造方法。4. A step of forming a second conductivity type silicon semiconductor layer on one surface of a first conductivity type silicon semiconductor substrate, and a step of forming a first insulating layer only in a predetermined region on the other surface of the silicon semiconductor substrate. Forming step, forming a first conductivity type microcrystalline silicon semiconductor layer having a higher concentration than the silicon semiconductor substrate so as to cover the predetermined region, and forming a second insulating layer on the microcrystalline silicon semiconductor layer A step of forming an opening in the second insulating layer corresponding to the predetermined region, and a step of forming a back surface electrode so as to cover the opening and connecting to the first conductivity type microcrystalline silicon semiconductor layer. And a step of performing a heat treatment at 300 to 400 ° C. after forming the back surface electrode, the method for producing a solar cell.
面上に第２導電型のシリコン半導体層を形成する工程
と、 上記シリコン半導体基板の他方面上の所定領域のみに第
１絶縁層を形成する工程と、 上記所定領域を覆うように上記シリコン半導体基板より
高濃度の第１導電型微結晶シリコン半導体層を形成する
工程と、 上記微結晶シリコン半導体層上に第２絶縁層を形成する
工程と、 上記所定領域に対応して第２絶縁層に開口部を形成する
工程と、 第１導電型であって上記微結晶シリコン半導体層より低
抵抗の層を上記微結晶シリコン半導体層に上記開口部に
対応させて形成する工程と、 上記開口部を覆うように裏面電極を形成して上記低抵抗
の層と接続する工程と、 裏面電極形成後に３００〜４００℃の熱処理を行う工程
と、を含むことを特徴とする太陽電池の製造方法。5. A step of forming a second conductivity type silicon semiconductor layer on one surface of a first conductivity type silicon semiconductor substrate, and a step of forming a first insulating layer only on a predetermined region on the other surface of the silicon semiconductor substrate. Forming step, forming a first conductivity type microcrystalline silicon semiconductor layer having a higher concentration than the silicon semiconductor substrate so as to cover the predetermined region, and forming a second insulating layer on the microcrystalline silicon semiconductor layer A step of forming an opening in the second insulating layer corresponding to the predetermined region, and a layer of a first conductivity type having a resistance lower than that of the microcrystalline silicon semiconductor layer is formed on the microcrystalline silicon semiconductor layer. A step of forming corresponding to the opening, a step of forming a back surface electrode so as to cover the opening and connecting to the low resistance layer, and a step of performing heat treatment at 300 to 400 ° C. after forming the back surface electrode, Including Method of manufacturing a solar cell according to claim.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30725395A JP3158028B2 (en) | 1995-07-25 | 1995-11-27 | Solar cell and method of manufacturing the same |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7-188997 | 1995-07-25 | ||
| JP18899795 | 1995-07-25 | ||
| JP30725395A JP3158028B2 (en) | 1995-07-25 | 1995-11-27 | Solar cell and method of manufacturing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0997916A true JPH0997916A (en) | 1997-04-08 |
| JP3158028B2 JP3158028B2 (en) | 2001-04-23 |
Family
ID=26505259
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP30725395A Expired - Fee Related JP3158028B2 (en) | 1995-07-25 | 1995-11-27 | Solar cell and method of manufacturing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3158028B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004100273A1 (en) | 2003-05-09 | 2004-11-18 | Shin-Etsu Handotai Co., Ltd. | Solar cell and process for producing the same |
| EP2626914A2 (en) | 2012-02-10 | 2013-08-14 | Shin-Etsu Chemical Co., Ltd. | Solar Cell and Method of Manufacturing the Same |
-
1995
- 1995-11-27 JP JP30725395A patent/JP3158028B2/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004100273A1 (en) | 2003-05-09 | 2004-11-18 | Shin-Etsu Handotai Co., Ltd. | Solar cell and process for producing the same |
| EP1630873A1 (en) * | 2003-05-09 | 2006-03-01 | Shin-Etsu Handotai Company Limited | Solar cell and process for producing the same |
| EP1630873A4 (en) * | 2003-05-09 | 2007-03-14 | Shinetsu Handotai Kk | Solar cell and process for producing the same |
| AU2004237524B2 (en) * | 2003-05-09 | 2009-09-17 | Shin-Etsu Chemical Co., Ltd. | Solar cell and process for producing the same |
| US8030223B2 (en) | 2003-05-09 | 2011-10-04 | Shin-Etsu Chemical Co., Ltd. | Solar cell and method of fabricating the same |
| EP2626914A2 (en) | 2012-02-10 | 2013-08-14 | Shin-Etsu Chemical Co., Ltd. | Solar Cell and Method of Manufacturing the Same |
| KR20130092494A (en) | 2012-02-10 | 2013-08-20 | 신에쓰 가가꾸 고교 가부시끼가이샤 | Solar cell and method of manufacturing the same |
| US9871156B2 (en) | 2012-02-10 | 2018-01-16 | Shin-Etsu Chemical Co., Ltd. | Solar cell and method of manufacturing the same |
| EP3712968A1 (en) | 2012-02-10 | 2020-09-23 | Shin-Etsu Chemical Co., Ltd. | Solar cell manufacturing method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3158028B2 (en) | 2001-04-23 |
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