200952185200952185
* I 九、發明說明： 【發明所屬之技術領域】 本案係關於一種光電元件及其製造方法’尤指一種太 陽能電池(Solar cell)及其製造方法。 【先前技術】 現今，由於全球能源的持續短缺且對於能源的需求與 ❿ 日俱增，因此如何提供環保且乾淨的能源便成為目前最迫 切需要研究的議題。在各種替代性能源的研究當中’利用 自然的太陽光經由光電能量轉換產生電能的太陽能電池’ 為目前所廣泛應用且積極研發之技術。 請參閱第一圖A-Η，其係顯示傳統微晶矽薄膜技術 (Micro-crystalline，mc-Si)之太陽能電池之製造流程結構示 意圖。如第一圖A所示，首先，提供p型半導體基板1〇， 並將P型半導體基板10的表面形成凹凸的紋理 (texturing)，以減低光線的反射率，其中由於凹凸的紋理 相當細微，因此在第一圖A中省略繪示。接著，提供摻雜 劑及利用熱擴散的方式在受光面S1形成由N-型半導體所 構成的射極層11 ( emitter)，且在p型半導體基板10與射 極層11之間形成pn接面。此時，在射極層η上亦會形成 雄矽玻璃層 12 ( phosphorous silicate glass，PSG)，如第一 圖B所示。之後，利用蝕刻的方式將表面的磷矽玻璃層12 移除，如第一圖C所示。再於射極層u上沈積一層由氮梦 6 200952185 化合物（SiNx)構成的抗反射膜 13( anti-reflection coating，* I. Description of the Invention: [Technical Field of the Invention] The present invention relates to a photovoltaic element and a method of manufacturing the same, and particularly to a solar cell and a method of manufacturing the same. [Prior Art] Nowadays, due to the continuous shortage of global energy and the increasing demand for energy, how to provide environmentally friendly and clean energy is the most urgent issue to be studied. In the research of various alternative energy sources, a solar cell that uses natural sunlight to generate electric energy via photoelectric energy conversion is a widely used and actively developed technology. Please refer to the first figure A-Η, which is a schematic diagram showing the manufacturing process structure of a conventional micro-crystalline (mc-Si) solar cell. As shown in FIG. A, first, a p-type semiconductor substrate 1 is provided, and the surface of the P-type semiconductor substrate 10 is textured to reduce the reflectance of the light, wherein the texture of the unevenness is rather fine. Therefore, it is omitted in the first drawing A. Next, a dopant layer and an emitter layer 11 made of an N-type semiconductor are formed on the light-receiving surface S1 by means of thermal diffusion, and a pn junction is formed between the p-type semiconductor substrate 10 and the emitter layer 11. surface. At this time, a phosphorous silicate glass (PSG) is also formed on the emitter layer η as shown in the first panel B. Thereafter, the surface of the phosphorous glass layer 12 is removed by etching as shown in the first panel C. An anti-reflection coating 13 (Anti-reflection coating) composed of Nitrogen 6 200952185 compound (SiNx) is deposited on the emitter layer u.
ARC)，以降低光線的反射率並保護射極層11，如第一圖D 所示；接著，利用蝕刻的方式選擇性地移除部分之抗反射 膜13並曝露出部分之射極層11 ’如第一圖E所示。隨後 進行第二次熱擴散，使曝露之射極層11部分形成高摻雜之 N+型半導體區域11’，如第一圖F所示；此時，在高摻雜 之N+型半導體區域11’上亦會形成磷矽玻璃層14，而該填 _ 矽玻璃層14則接著以蝕刻方式移除，如第一圖g所示。 & 之後’使用網版印刷（screen printing)技術將銘導電材料 印刷在背光面S2上，再以同樣的方式將銀導電材料印刷在 受光面S1上’最後進行燒結（firing)步驟，使受光面si 產生第一電極15，以及背光面S2產生背表面電場層 (back surface field，BSF)以及第二電極 π，如第一圖 H 所示’藉此以完成太陽能電池之製造。 上述製私係形成具選擇性射極（selective emitter ) ❹之太陽能電池，亦即在不同的區域中形成摻雜濃度高低不 同、擴散深淺不同之射極區域，例如在受光面S1之第一電 極15下形成高摻雜之N+型半導體區域u，，其他區域則形 成低摻雜之N-型半導體區域u (如第一圖H所示）。由於 選擇性射極具有兩種不同之摻雜區域，可降低第一電極15 與射極之間的接觸電阻（c〇ntact resistance)，並降低太陽 月b電池表面的電子電洞再結合率（rec〇mbjnati〇n rate)，使得 太陽能電池對藍光的吸收增加，因而提高整個太陽能電池 的光電轉換效率。 7 200952185 習知太陽能電池於製造時，通常係以電漿輔助化學氣 相沉積法（plasma enhanced chemical vapor deposition， PECVD )於該半導體基板l〇上形成氮矽化合物（SiNx:H) 層以構成抗反射膜13 ’其優點包含可用來降低光線的反射 率並保護射極層11，尤其在该氮梦化合物層形成之抗反射 膜13内含有大量的氫，在後續的加熱製程中，氫可穿透至 矽晶片之P型半導體基板1〇内部進行氫鈍化過程，當氫穿 透的量越大時，則太陽能電池之效能越好，因此一般的太 陽能電池通常係以電漿辅助化學氣相沉積法來形成抗反射 膜13之氮矽化合物，然而，習知太陽能電池在第二次形成 磷矽玻璃層14(如第一圖F所示）之熱擴散過程中係以三氯 氧填(P0C13)為擴散源進行鱗捧雜，此三氯氧填之熱擴散過 程以及以姓刻方式移除填碎玻璃層14(如第一圖G所示）之 過程中’會對以電漿輔助化學氣相沉積法形成之氮矽化合 物產生極大的破壞’使得抗反射膜13之厚度變薄，進而影 響太陽能電池之效能。 因此，如何發展一種可改善上述習知技術缺失之太陽 月&電池及其製造方法，實為目前迫切需要解決之問題。 【發明内容】 本案之主要目的在於提供一種太陽能電池及其製造方 法，其係利用保護薄膜覆蓋於抗反射膜上，以解決傳統太 陽能電池因抗反射制於三氯氧叙熱擴散過程以及移除 磷矽玻璃層之蝕刻過程中受到破壞而導致厚度變薄，進而 8 200952185 影響太陽能電池之效能之缺失。 太陽ίίΓ目的’本案之一較廣義實施態樣為提供-種 ΐ 該太陽能電池至少包含：半導體基板;射極 二門形ΐ 基板之至少—表面上，且與半導體基板 ρη接面；抗反射膜’形成於該射極層上； 溥膜，形成於該抗反射膜上；射 ’、 射極接觸區域，形成於射極 ❹ φ 層的射4域；以及-第一電極，與射極接觸區域連接。 種太目的，本案之另一較廣義實施態樣為提供- 製造方法，該方法至少包含步驟:⑷提供 層間形成沖接面，.⑹於射極層上形成 之佯1¾㈣i於抗反射膜上形成保護薄膜；⑷移除部分 ^呆㈣膜及抗反射膜並曝^部分 形成至少—射極接觸區域以= 至夕一第一電極於該射極接觸區域。 【實施方式】 明t:=T優點的—些典型實施例將在後段的說 二==是本案能夠在不同的態様上具有 脫離本$的範圍，且其中的說明及圖 不在本質上係备作㈣之用’而非用以限制本案。 電池之製造流程結構示意圖。如第二圖丄首= 9 200952185ARC) to reduce the reflectivity of the light and protect the emitter layer 11, as shown in the first diagram D; then, selectively remove a portion of the anti-reflection film 13 by etching and expose a portion of the emitter layer 11 'As shown in the first picture E. A second thermal diffusion is then performed to partially expose the exposed emitter layer 11 to the highly doped N+ type semiconductor region 11', as shown in FIG. F; at this time, in the highly doped N+ type semiconductor region 11' A phosphorous-glass layer 14 is also formed thereon, and the filled-glass layer 14 is then removed by etching, as shown in the first graph g. & then 'printing the conductive material on the backlight surface S2 using screen printing technology, and printing the silver conductive material on the light-receiving surface S1 in the same manner'. Finally, the firing step is performed to receive the light. The face si generates the first electrode 15, and the backlight surface S2 generates a back surface field (BSF) and a second electrode π, as shown in the first figure H, to complete the manufacture of the solar cell. The above-mentioned system forms a solar cell with a selective emitter, that is, an emitter region having different doping concentrations and different diffusion depths in different regions, for example, a first electrode on the light receiving surface S1. A highly doped N+ type semiconductor region u is formed under 15, and other regions form a low doped N-type semiconductor region u (as shown in the first figure H). Since the selective emitter has two different doping regions, the contact resistance between the first electrode 15 and the emitter can be reduced, and the electron hole recombination rate on the surface of the solar cell b can be reduced ( Rec〇mbjnati〇n rate), so that the absorption of blue light by the solar cell is increased, thereby improving the photoelectric conversion efficiency of the entire solar cell. 7 200952185 Conventional solar cells are usually fabricated by plasma enhanced chemical vapor deposition (PECVD) to form a layer of nitrogen bismuth compound (SiNx:H) on the semiconductor substrate to form an anti- The reflective film 13' has the advantages of reducing the reflectivity of the light and protecting the emitter layer 11, in particular, the anti-reflection film 13 formed by the nitrogen compound layer contains a large amount of hydrogen, and in the subsequent heating process, the hydrogen can be worn. The hydrogen passivation process is performed inside the P-type semiconductor substrate 1 of the germanium wafer. When the amount of hydrogen permeation is larger, the solar cell performance is better. Therefore, the general solar cell is usually plasma-assisted chemical vapor deposition. The method is to form a nitrogen bismuth compound of the anti-reflection film 13, however, the conventional solar cell is filled with trichlorooxide during the thermal diffusion process of the second formation of the phosphorous-glass layer 14 (as shown in FIG. F) (P0C13). ) for the diffusion source, the thermal diffusion process of the trichlorooxane filling and the removal of the glass frit layer 14 by the surname (as shown in the first graph G) will be plasma-assisted chemistry Nitrogen bonded silicide phase deposition method of forming a tremendous damage 'such that the antireflection film 13 of the thin thickness, and thus affect the efficiency of the solar cell. Therefore, how to develop a solar cell & battery and a method for manufacturing the same that can improve the above-mentioned conventional techniques is an urgent problem to be solved. SUMMARY OF THE INVENTION The main object of the present invention is to provide a solar cell and a manufacturing method thereof, which are coated on an anti-reflection film by using a protective film to solve the problem that the conventional solar cell is diffused and prevented by the anti-reflection process. The thickness of the phosphorous-glass layer is destroyed during the etching process, resulting in a thinning of the thickness of the solar cell. The solar cell is provided in a generalized embodiment. The solar cell comprises at least: a semiconductor substrate; at least a surface of the emitter two-gate substrate, and a surface of the semiconductor substrate; the anti-reflection film Formed on the emitter layer; a ruthenium film formed on the anti-reflection film; an emitter', an emitter contact region formed in the emitter 4 region of the emitter φ φ layer; and a first electrode, the emitter contact region connection. Another purpose of the present invention is to provide a manufacturing method comprising at least the steps of: (4) providing a nip between the layers, and (6) forming a 佯13⁄4(4)i formed on the emitter layer on the antireflective film. a protective film; (4) removing a portion of the film (4) and the anti-reflective film and exposing the portion to form at least an emitter contact region to the first electrode in the emitter contact region. [Embodiment] The typical embodiment of the t:=T advantage will be described in the following paragraph === This is the case that the case can be deviated from the scope of the $ in different states, and the description and the diagram are not in essence. Use (4) instead of limiting the case. Schematic diagram of the manufacturing process of the battery. As shown in the second figure = 9 200952185
• I 供半導體基板20 ’並將半導體基板20的表面形成凹凸紋 理，以減低光線的反射率’其中由於凹凸紋理相當細微， 因此在第二圖A中省略繪示。於一些實施例中，半導體基 板20可為但不限於P型矽基板’且於半導體基板20表面 形成凹凸紋理的方式可採用但不限於濕蝕刻或反應性離子 蝕刻等方式。 接著，如第一圖B所示’先提供摻雜劑以及利用例如 ❹ 熱擴散的方式在半導體基板2〇之受光面S1形成射極層 21，於本實施例中’射極層可為但不限為N型射極層，且 在半導體基板20與射極層21之間形成pn接面，此時，在 射極層21上亦會形成磷矽玻璃層22，其後，再利用蝕刻 的方式將磷矽玻璃層22移除(如第二圖C所示），此時，在 半導體基板20上僅覆蓋射極層21。 隨後，如第二圖D所示’以電漿辅助化學氣相沉積法 (plasma enhanced chemical vapor deposition，PECVD)於 ❹ 受光面SI沈積一氮石夕化合物（SiNx)層於射極層21上， 以形成一抗反射膜23，其係具有可降低光線的反射率、保 護射極層21並具有高通透性等優點，可使氫由抗反射膜 23内大量穿透至石夕晶片之半導體基板2〇内部，以進行氫 鈍化過程，進而提升太陽能電池之效能。於一些實施例申， 抗反射膜23亦可由氮化石夕、氧化矽、二氧化鈦、氧化鋅、 氧化錫、二氧化鎂等材質構成，且不以此為限。另外於 本實施例中，抗反射膜23之厚度可為70-no nm，其厚度 係可因實際施作情形而任施變化，並不以此為限。 200952185 • , 接著，再如第二圖E所示，以低壓化學氣相沉積法(low pressure chemical vapor deposition，LPVCD)於受光面 S1 再沈積一較薄之氮矽化合物（SiNx)層於抗反射膜23之 上，以形成一保護薄膜24，其係具有良好之抗熱及抗化學 之特性，可用以保護抗反射膜23於後續熱擴散及磷矽玻璃 層26移除過程中不受破壞，以及，保護薄膜24同樣可降 低光線反射率’且保有抗反射膜23之氫鈍化的特性。另 ❹ 外，於本實施例中’該保護薄膜24係為四氮化三矽 (Si3N4) ’且其厚度係為5-20nm，但不以此為限，該保護薄 膜24之材質及厚度係可依實際施作情形而任施變化。 之後，再如第二圖F所示，移除部分之抗反射膜23及 保護薄膜24,並曝露出部分之射極層21，其中，移除部分 抗反射膜23及保護薄膜24的方法可採用但不限於蝕刻方 式或雷射加熱方式。 接著，再將上述半導體結構放入熱擴散爐中，以三氯 ί 氧磷（POC13)為擴散源進行磷摻雜，如第二圖^所示， 使曝露之部分射極層21形成高摻雜之Ν+半導體區域^， 並且在高摻雜之Ν+半導體區域25上形成一磷矽玻屏 26，藉此擴散製程以形成具有高摻雜區域及低摻雜區口 射極層21，其中，該高摻雜之Ν+半導體區域25係 陽能電池之射極接觸區域。 、馬太 隨後，利用蝕刻的方式將表層的磷矽玻璃層％ 如第二圖Η所示。於一實施例中，該餘刻方式可為但不于'， 於氫氟酸濕钱刻（HFdip)，且鱗石夕玻璃層26係可輕易藉 11 200952185 身 . 由氫氟醆濕餘刻而移除。 其後’如第二圖I所示，透過金屬鍍膜(Metallization) 過程’於射極接觸區域上形成第一電極27,於本實施例中， 第一電極27可為但不限為銀。並且，使用網版印刷技術將 導電材料28形成於背光面S2上。於此實施例中，導電材 料28可為但不限於鋁。此外’背光面S2部份半導體基板 20因導電材料28導熱而形成背表面電場層20,，並且背光 φ 面S2之部分導電材料28形成第二電極29，藉此以完成太 陽能電池之製造。 综上所述，本案所提供之太陽能電池及其製造方法主 要係於以電漿輔助化學氣相沉積法形成之抗反射膜上覆蓋 一層以低壓化學氟相沉積法形成之保護薄膜’藉由保護薄 膜具有良好之抗熱及抗化學之特性，進而可保護抗反射 膜，俾可大幅改善習知抗反射膜於後續製造過程中，例如： 三氣氧構之熱擴散過程以及移除碟梦玻璃層之姑刻過程 ❹ 等’因遭受破壞而使其厚度變薄’進而影響其抗反射性及 太陽能電池之效能等缺點，並可進一步增加太陽能電池之 良率。是以，本案之太陽能電池及其製造方法具有極高之 實用性，實為一具虞業價值之發明，爰依法提出申請。 本案得由熟習此技術之人士任施匠思而為諸般修飾， 然皆不脫如附申讀專利範圍所欲保護者。 12 200952185• I is supplied to the semiconductor substrate 20' and the surface of the semiconductor substrate 20 is textured to reduce the reflectance of the light. </ RTI> Since the uneven texture is relatively fine, it is omitted in the second drawing A. In some embodiments, the semiconductor substrate 20 can be, but not limited to, a P-type germanium substrate, and a textured texture can be formed on the surface of the semiconductor substrate 20, but is not limited to wet etching or reactive ion etching. Next, as shown in FIG. B, 'the dopant layer is first provided and the emitter layer 21 is formed on the light-receiving surface S1 of the semiconductor substrate 2 by, for example, thermal diffusion. In the present embodiment, the 'emitter layer can be It is not limited to an N-type emitter layer, and a pn junction is formed between the semiconductor substrate 20 and the emitter layer 21. At this time, a phosphor glass layer 22 is also formed on the emitter layer 21, and then etching is performed. The phosphorous glass layer 22 is removed (as shown in FIG. 2C), at which time only the emitter layer 21 is covered on the semiconductor substrate 20. Subsequently, as shown in FIG. D, 'a plasma-assisted chemical vapor deposition (PECVD) is deposited on the emitter layer 21 on the ❹ light-receiving surface SI, a layer of a Nitrix compound (SiNx) layer, An anti-reflection film 23 is formed, which has the advantages of reducing the reflectance of light, protecting the emitter layer 21, and having high permeability, and allowing a large amount of hydrogen to penetrate from the anti-reflection film 23 to the semiconductor of the Shixi wafer. The inside of the substrate 2 is used to perform a hydrogen passivation process, thereby improving the performance of the solar cell. In some embodiments, the anti-reflection film 23 may be made of a material such as cerium nitride, cerium oxide, titanium dioxide, zinc oxide, tin oxide, or magnesium dioxide, and is not limited thereto. In addition, in the present embodiment, the thickness of the anti-reflection film 23 may be 70-no nm, and the thickness thereof may be varied depending on the actual application, and is not limited thereto. 200952185 • Then, as shown in the second figure E, a thinner nitrogen bismuth compound (SiNx) layer is deposited on the light-receiving surface S1 by low pressure chemical vapor deposition (LPVCD) for anti-reflection. Above the film 23, a protective film 24 is formed which has good heat and chemical resistance properties and can be used to protect the anti-reflective film 23 from damage during subsequent thermal diffusion and removal of the phosphorous glass layer 26, Further, the protective film 24 can also reduce the light reflectance 'and maintain the hydrogen passivation property of the anti-reflection film 23. In addition, in the present embodiment, the protective film 24 is made of silicon nitride (Si3N4) and the thickness thereof is 5-20 nm, but not limited thereto, the material and thickness of the protective film 24 are Changes may be made depending on the actual application. Then, as shown in FIG. F, a portion of the anti-reflection film 23 and the protective film 24 are removed, and a portion of the emitter layer 21 is exposed, wherein the method of removing the portion of the anti-reflection film 23 and the protective film 24 can be performed. Use, but not limited to, etching or laser heating. Then, the semiconductor structure is placed in a thermal diffusion furnace, and phosphorus doping is performed using phosphorus oxychloride (POC13) as a diffusion source. As shown in FIG. 2, the exposed partial emitter layer 21 is highly doped. a semiconductor region ^, and a phosphor screen 26 is formed on the highly doped germanium + semiconductor region 25, whereby the diffusion process is performed to form the emitter layer 21 having a highly doped region and a low doped region. Wherein, the highly doped germanium + semiconductor region 25 is an emitter contact region of the anode battery. Matthew Subsequently, the surface layer of the phosphorous-glass layer is etched as shown in the second figure. In an embodiment, the residual mode may be but not ', in hydrofluoric acid wet etching (HFdip), and the scale stone layer 26 can easily borrow 11 200952185 body. And removed. Thereafter, as shown in the second FIG. 1, a first electrode 27 is formed on the emitter contact region through a metallization process. In the present embodiment, the first electrode 27 may be, but is not limited to, silver. Also, the conductive material 28 is formed on the backlight surface S2 using a screen printing technique. In this embodiment, the electrically conductive material 28 can be, but is not limited to, aluminum. Further, the portion of the semiconductor substrate 20 of the backlight surface S2 is thermally formed by the conductive material 28 to form the back surface electric field layer 20, and a portion of the conductive material 28 of the backlight φ surface S2 forms the second electrode 29, thereby completing the fabrication of the solar cell. In summary, the solar cell and the manufacturing method thereof provided by the present invention are mainly for protecting the anti-reflection film formed by the plasma-assisted chemical vapor deposition method with a protective film formed by a low-pressure chemical fluorine phase deposition method. The film has good heat and chemical resistance, which can protect the anti-reflection film. It can greatly improve the conventional anti-reflection film in the subsequent manufacturing process, for example: the heat diffusion process of the three gas oxygen structure and the removal of the dish glass The layering process of the layer, such as thinning its thickness due to damage, affects its anti-reflection and solar cell performance, and can further increase the yield of solar cells. Therefore, the solar cell and its manufacturing method of the present invention have extremely high practicality, and it is an invention of industrial value, and the application is made according to law. This case has to be modified by people who are familiar with this technology, but it is not to be protected as intended. 12 200952185
【圖式簡單說明】 第一圖A-Η:係為傳統太陽能電池之製造流程結構示意圖。 第二圖A-Ι:係為本案較佳實施例之太陽能電池之製造流程 結構不意圖。 13 200952185 【主要元件符號說明】 10、20:半導體基板 1卜21 :射極層 11’、25 :高摻雜之N+型半導體區域 12、 14、22、26 :雜夕玻璃層 13、 23 :抗反射膜 ❹ 15、27:第一電極 16、 20’ ：背表面電場層 17、 29 :第二電極 24 :保護薄膜 28 :導電材料 51 :受光面 52 :背光面 φ 14[Simple description of the diagram] The first diagram A-Η: is a schematic diagram of the manufacturing process structure of a conventional solar cell. Second Figure A-Ι: The manufacturing process of the solar cell of the preferred embodiment of the present invention is not intended. 13 200952185 [Description of main component symbols] 10, 20: semiconductor substrate 1 21: emitter layer 11', 25: highly doped N + -type semiconductor regions 12, 14, 22, 26: solar glass layers 13, 23: Antireflection film ❹ 15, 27: first electrode 16, 20': back surface electric field layer 17, 29: second electrode 24: protective film 28: conductive material 51: light receiving surface 52: backlight surface φ 14