201021221 w 六、發明說明： 【發明所屬之技術領域】 本案係關於一種光電元件之製造方法，尤指一種雙面 太陽能電池(Solar cell)之製造方法。 【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 曰倶增’因此如何提供環保且乾淨的能源便成為目前最迫 ❹ 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，且隨著太陽能電池 研發技術之精進，更已研發出雙面之太陽能電池(Bifacial Solar Cell) ’藉由太陽能電池雙面受光之設計，使得太陽能 電池的兩個表面皆可接收光線，並轉換太陽能，進而可有 效地提升雙面太陽能電池之效率。 請參閱第一圖A-E，其係顯示傳統雙面多晶梦薄膜技 ❹ 術(Multi-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10， 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第一表面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11上亦會形 成鱗發玻璃層 12 (Phosphoroussilicateglass，PSG) ’ 如第 201021221 t 一圖B所示。之後，利用钱刻的方式將表面的破石夕玻璃層 12移除，如第一圖C所示。 接著，再如第一圖D所示，使用沈積(Depositi〇n)的方 式於射極層12上形成一層由氮矽化合物（&Νχ)構成的第 一抗反射膜 13 (Anti-reflection coating，ARC)，以降低光 線的反射率並保護射極層12。其後，如第一圖e所示，同 樣於第二表面S2上以三溴化硼(BBr3)做為擴散源進行摻 雜’形成背表面電場層14(Back surface field，BSF)，並再 β 沈積一層由氮矽化合物構成的第二抗反射膜15，之後，再 使用網版印刷（Screen Printing)技術將鋁導電材料印刷在第 一表面S1上，且以同樣的方式將銀導電材料印刷在第二表 面S2上。最後，進行燒結(Firing)步驟，使第一表面S1產 生第一電極Ιό ’以及第二表面S2產生第二電極π，藉此 以完成太陽能電池之製造。 然而在此傳統雙面太陽能電池的製造過程中，主要是 以液態之三溴化硼(ΒβΓ3)做為擴散源，由惰性載送氣體輸 送，例如.Ν2，於樣品表面進行摻雜（Diffusi〇n)，然而三 漠化刪在進行熱擴散過程時需要極高的溫度，才能使硼擴 散至P型半導體基板10内形成P+層，上述之熱擴散過程 不僅製程步驟繁複，且所需花費的時間較久，因而會延長 整體製程時間，且會耗費較高的成本，除此之外，在此熱 擴散的過程中亦會對P型半導體基板10產生極大的破壞， 進而影響雙面太陽能電池之效能。 因此，如何發展一種可節省雙面太陽能電池之製造成 本，且能使雙面太陽能電池之製造過程更為快速、有效率 1 201021221 之製造方法，實為目前迫切需要解決之問題。 【發明内容】 本案之一目的在於提供一種雙面太陽能電池之製造方 法’其係 3A族元素做為摻㈣，铸決傳統雙面太 陽能電池因三溴化硼之熱擴散過程需要較高的溫度且需時 較久，使得製造成本較高，且因該熱擴散過程會^害p型 半導體基板，進而影響雙面太陽能電池之效能之缺失。 ❹ 為達上述目的，本案之一較廣義實施態樣為提供一種 雙面太陽能電池之製造方法，至少包含步驟：提供半導體 基板；於半導體基板之第一表面上形成射極層，並於半導 體基板與射極層間形成pn接面；於射極層上形成第一抗反 射膜’於半導體基板之第二表面上以網版印刷技術形成掺 雜源層，於半導體基板與換雜源層間形成背表面電場層； 於背表面電場層上形成第二抗反射膜；於第二表面上形成 至少一第二電極；以及於第一表面上形成至少一第一電極。 參 為達上述目的，本案之另一較廣義實施態樣為提供一 種雙面太陽能電池之製造方法，至少包含步驟：提供半導 體基板；於半導體基板之第一表面上形成射極層，並於韦 導體基板與射極層間形成pn接面；於射極層上形成第一抗 反射膜；於半導體基板之第二表面上形成摻雜源層；於半 導體基板與摻雜源層間形成背表面電場層；於背表面電場 層上形成第一抗反射膜；於第二表面上形成至少一第二電 極；以及於第一表面上形成至少一第一電極。 6 201021221 9 【實施方式】 體現本案特徵與優點的一些典型實施例將在後段的說 明中詳細敘述。應理解的是本案能夠在不同的態樣上具有 各種的變化’其皆不脫離本案的範圍，且其中的說明及圖 示在本質上係當作說明之用，而非用以限制本案。 »月參閱第一圖A-L ’其係顯不本案較佳實施例之雙面 太陽能電池之製造流程結構示意圖。如第二圖A所示，首 先，提供半導體基板20，並將半導體基板20的第一表面 ® S1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型石夕基板，且於半導體 基板20之第一表面si形成凹凸紋理的方式可採用但不限 於濕钱刻或反應性離子兹刻等方式。 接著’如第二圖B所示’先提供摻雜劑以及利用例如 熱擴散的方式在半導體基板2〇之第一表面si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 ❹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 沈積一氮矽化合物層於第一表面S1之射極層21上，以形 成第一抗反射膜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，可使氫由第一抗反射膜 23内大f穿透切晶片之半導體基板2()内部，以進行氫 201021221 鈍化過程，進而提升太陽能電池之效能。於一些實施例中， 第一抗反射膜23亦可由氮化矽、二氧化矽、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。 接著，再如第二圖E所示，於半導體基板2〇之第二表 面S2上形成一層摻雜源層24，當摻雜源層24形成於第二 表面S2上之後，則如第二圖F所示，再進行爐管燒結之步 驟’使半導體基板20之第二表面S2與摻雜源層24之間產 生一背表面電場層25。 其中，摻雜源層24係由3A族之元素所構成，且其製 程係可採用網版印刷技術，或以濺鍍（Sputtedng)技術形 成摻雜源層24，舉例來說，當以網版印刷技術形成摻雜源 層24時，係可將3A族元素之膠質薄膜，例如：鋁膠、硼 膠等，但不以此為限，印刷附著於第二表面幻上，以形成 摻雜源層24。於另一些實施例中，亦可以3A族之元素做 為靶材進行濺鍍，且於半導體基板2〇之第二表面S2上形 成摻雜源層24。 如此一來，在摻雜源層24的製造過程中，無論是以網 版印刷技術或是以濺鍍技術形成摻雜源層24,其製程步驟 均較為簡便，且可大幅縮短製程時間，另外，在後續進行 爐管燒結的步驟巾，所需耗費的時間純為簡短，因此可 有效節省成本及製程時間。 其後’再如第二圖G所示，移除覆蓋於第二表面S2 上之摻雜源層24 ’於本實施财，係以單面侧㈣啦硫 etch)之方式移除掺雜源層24’但不以此為限，以及單面蝕 刻係可為但不限為化學餘刻（chemical etch)或是乾蚀刻（吻 201021221 etch) ° 接著，再如第二圖H所示，於背表面電場層25上沈 積一層由氮石夕化合物構成的第二抗反射膜26，以降低光線 的反射率並保護背表面電場層25。 之後，再如第二圖I所示，移除部分之第二抗反射膜 26 ’並曝露出部分之背表面電場層25，以形成複數個開口 26a，其中，移除部分第二抗反射臈26的方法可採用但不 限於蝕刻方式或雷射加熱方式。 接著，則如第二圖J所示，於第二表面S2進行金屬鍍 膜(Metallization)過程，其中，金屬鍍膜過程係可採用網版 印刷技術、電鍍(plating)技術或是濺鍍技術將第二導電材料 27a’例如：鋁、銀，但不以此為限，形成於第二表面幻 上。 一好於另一實施例中，第二抗反射膜26亦可由二氧化矽、 了氧化鈦、氧化鋅、氧化錫、二氧化鎮等材質構成且不 士 ^為限’且當第二抗反射膜26係由上述之氧化合物所形 、’則不需進行第二^所示之移除部分第二抗反射膜 嫌％ ^程、可於第二圖H所示形成第二抗反射膜26之步 接進行如第二圖J所示之金屬鍍膜(Metallizati〇n)過 程，將第二導電材料27a形成於第二表面幻上。201021221 w VI. Description of the invention: [Technical field to which the invention pertains] The present invention relates to a method of manufacturing a photovoltaic element, and more particularly to a method of manufacturing a double-sided solar cell. [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 that needs to be studied. In the research of various alternative energy sources, solar cells that use natural sunlight to generate electric energy through photoelectric energy conversion are widely used and actively developed technologies, and with the advancement of solar cell research and development technology, Bifacial Solar Cell 'By the solar cell's double-sided light design, the two surfaces of the solar cell can receive light and convert solar energy, which can effectively improve the efficiency of the double-sided solar cell. Please refer to the first figure A-E, which is a schematic diagram showing the manufacturing process of a conventional double-sided poly-crystalline (mc-Si) solar cell. As shown in FIG. A, first, a p-type semiconductor substrate 10 is provided, and a 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. It is omitted in the first drawing A. Next, a dopant layer and an emitter layer 11 (Emitter) composed of an N+ type semiconductor are formed on the first 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 Layer 12 (PSG) is formed on the emitter layer 11 as shown in Fig. 201021 21 t. Thereafter, the surface of the broken glass layer 12 is removed by means of money engraving, as shown in the first panel C. Then, as shown in the first figure D, a first anti-reflection coating composed of a nitrogen bismuth compound (& Νχ) is formed on the emitter layer 12 by deposition (Anti-reflection coating). , ARC) to reduce the reflectivity of the light and protect the emitter layer 12. Thereafter, as shown in the first diagram e, doping is performed on the second surface S2 with boron tribromide (BBr3) as a diffusion source to form a back surface field layer (BSF), and then沉积 depositing a second anti-reflection film 15 composed of a nitrogen ruthenium compound, and then printing an aluminum conductive material on the first surface S1 using Screen Printing technology, and printing the silver conductive material in the same manner On the second surface S2. Finally, a Firing step is performed to cause the first surface S1 to generate the first electrode Ιό ' and the second surface S2 to generate the second electrode π, thereby completing the fabrication of the solar cell. However, in the manufacturing process of the conventional double-sided solar cell, the liquid boron tribromide (ΒβΓ3) is mainly used as a diffusion source, and is transported by an inert carrier gas, for example, Ν2, to be doped on the surface of the sample (Diffusi〇) n), however, the three desertifications require a very high temperature in the thermal diffusion process in order to diffuse boron into the P-type semiconductor substrate 10 to form a P+ layer. The above thermal diffusion process is not only complicated, but also requires a cost. The longer the time, the longer the overall process time will be, and the higher the cost. In addition, the P-type semiconductor substrate 10 will be greatly damaged during the thermal diffusion process, thereby affecting the double-sided solar cell. Performance. Therefore, how to develop a manufacturing method that can save the manufacturing cost of the double-sided solar cell and make the manufacturing process of the double-sided solar cell faster and more efficient 1 201021221 is an urgent problem to be solved. SUMMARY OF THE INVENTION One object of the present invention is to provide a method for manufacturing a double-sided solar cell, which is a 3A group element as a doping (four), which requires a higher temperature due to the thermal diffusion process of boron tribromide. Moreover, it takes a long time to make the manufacturing cost high, and the thermal diffusion process may damage the p-type semiconductor substrate, thereby affecting the lack of performance of the double-sided solar cell. ❹ In order to achieve the above object, a generalized embodiment of the present invention provides a method for manufacturing a double-sided solar cell, comprising at least the steps of: providing a semiconductor substrate; forming an emitter layer on the first surface of the semiconductor substrate, and forming a semiconductor layer on the semiconductor substrate Forming a pn junction with the emitter layer; forming a first anti-reflection film on the emitter layer to form a doped source layer on the second surface of the semiconductor substrate by a screen printing technique, and forming a back between the semiconductor substrate and the impurity-changing layer a surface electric field layer; forming a second anti-reflection film on the back surface electric field layer; forming at least one second electrode on the second surface; and forming at least one first electrode on the first surface. In order to achieve the above object, another broad aspect of the present invention provides a method for manufacturing a double-sided solar cell, comprising at least the steps of: providing a semiconductor substrate; forming an emitter layer on the first surface of the semiconductor substrate, and Forming a pn junction between the conductor substrate and the emitter layer; forming a first anti-reflection film on the emitter layer; forming a doped source layer on the second surface of the semiconductor substrate; and forming a back surface electric field layer between the semiconductor substrate and the doped source layer Forming a first anti-reflection film on the back surface electric field layer; forming at least one second electrode on the second surface; and forming at least one first electrode on the first surface. 6 201021221 9 [Embodiment] Some exemplary embodiments embodying the features and advantages of the present invention will be described in detail in the following description. It is to be understood that the present invention is capable of various modifications in the various aspects of the invention, and the description and the drawings are in the nature of Referring to the first figure A-L', the structure of the manufacturing process of the double-sided solar cell of the preferred embodiment of the present invention is shown. As shown in the second diagram A, first, the semiconductor substrate 20 is provided, and the first surface ® S1 of the semiconductor substrate 20 is formed into a textured texture to reduce the reflectance of the light, wherein the concave and convex texture is relatively fine, so in the second figure A The illustration is omitted. In some embodiments, the semiconductor substrate 20 may be, but not limited to, a p-type slab substrate, and a concave-convex texture may be formed on the first surface si of the semiconductor substrate 20, but is not limited to wet etching or reactive ion etching. the way. Then, as shown in FIG. B, 'the dopant layer is first provided and the emitter layer 21 is formed on the first surface si of the semiconductor substrate 2 by, for example, thermal diffusion. In this embodiment, the emitter layer may 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 reused. The phosphor glass layer 22 is removed by etching (as shown in the second figure c), at which time only the emitter layer 21 is covered on the semiconductor substrate 20. Subsequently, as shown in FIG. D, a layer of a ruthenium ruthenium compound is deposited on the emitter layer 21 of the first surface S1 by plasma-assisted chemical vapor deposition to form a first anti-reflection film 23, which has a The utility model has the advantages of reducing the reflectance of the light, protecting the emitter layer 21 and having high permeability, and the hydrogen can be penetrated from the inside of the semiconductor substrate 2 () of the cut wafer by the large f in the first anti-reflection film 23 to perform passivation of hydrogen 201021221. Process to improve the performance of solar cells. In some embodiments, the first anti-reflection film 23 may be made of a material such as tantalum nitride, hafnium oxide, titanium dioxide, zinc oxide, tin oxide, or magnesium dioxide, and is not limited thereto. Then, as shown in the second figure E, a doping source layer 24 is formed on the second surface S2 of the semiconductor substrate 2, and after the doping source layer 24 is formed on the second surface S2, as shown in the second figure. As shown by F, the step of sintering the furnace tube is further performed to generate a back surface electric field layer 25 between the second surface S2 of the semiconductor substrate 20 and the dopant source layer 24. Wherein, the doping source layer 24 is composed of elements of the 3A group, and the process thereof may adopt a screen printing technique or a doping source layer 24 by sputtering, for example, when using a screen When the doping source layer 24 is formed by a printing technique, a colloidal film of a 3A group element, such as an aluminum paste or a boron adhesive, may be used, but not limited thereto, and the printing is attached to the second surface to form a doping source. Layer 24. In other embodiments, the 3A element can also be sputtered as a target, and the doped source layer 24 can be formed on the second surface S2 of the semiconductor substrate 2 . In this way, in the manufacturing process of the doped source layer 24, whether the screen source technology is formed by screen printing technology or by sputtering technology, the process steps are relatively simple, and the process time can be greatly shortened, and In the subsequent step of sintering the tube, the time required is purely short, so that cost and process time can be effectively saved. Thereafter, as shown in the second figure G, the doped source layer 24' covering the second surface S2 is removed, and the doping source is removed by the single-sided side (four) sulfur etch). The layer 24' is not limited thereto, and the single-sided etching system may be, but is not limited to, a chemical etch or a dry etch (kiss 201021221 etch). Then, as shown in the second figure H, A second anti-reflection film 26 composed of a Nitrogen compound is deposited on the back surface electric field layer 25 to reduce the reflectance of the light and protect the back surface electric field layer 25. Thereafter, as shown in FIG. 1A, a portion of the second anti-reflection film 26' is removed and a portion of the back surface electric field layer 25 is exposed to form a plurality of openings 26a, wherein a portion of the second anti-reflection layer is removed. The method of 26 may be, but not limited to, an etching method or a laser heating method. Then, as shown in the second figure J, a metallization process is performed on the second surface S2, wherein the metal plating process can be performed by using a screen printing technique, a plating technique, or a sputtering technique. The conductive material 27a' is, for example, aluminum or silver, but is not limited thereto, and is formed on the second surface. In another embodiment, the second anti-reflection film 26 may also be made of a material such as ceria, titanium oxide, zinc oxide, tin oxide, or oxidized town, and is not limited to 'and when the second anti-reflection The film 26 is formed by the above-mentioned oxygen compound, and the second anti-reflection film 26 is formed without removing the second anti-reflection film shown in FIG. Steps are followed by a metallization process as shown in FIG. J, and the second conductive material 27a is formed on the second surface.
App 1實施例巾第二導電材料27a係為18，但不以此 U W以網版印刷技術將銘導電材料沉積於第二表面S2 ，=可進行燒結步驟，用以於第二表面幻之開口 W 處元成第二電極27。 接著再如第二圖K所示，於第-表面S1上進行金 201021221 • · 屬鍍膜過程，於本實施例中，係使用網版印刷技術將第〆 導電材料28a形成於第一表面S1上’再如第二圖l所承， 進行燒結步雜，使第一表面S1上之第一導電材料28a形成 第一電極28，其中該第一電極28穿過第一抗反射膜23炎 延伸連接至射極層21’藉此以完成雙面太陽能電池之製造。 綜上所述，本案所提供之雙面太陽能電池之製造方法 主要係利用3A族元素做為摻雜源，且採用網版印刷技術 或賤鑛技術於雙面太陽能電池之第二表面形成摻雜源層， ❿ 藉由此摻雜源及對應之製造技術以有效簡化製程，並可大 幅縮短整體之製程時間，且可進一步節省成本，俾可改善 習知技術中採用三溴化硼之熱擴散過程需要較高的溫度且 需時較久，導致製造成本較高，且會損害P型半導體基板 及影響雙面太陽能電池之效能等缺點，使得雙面太陽能電 池之製造過程更為簡便、快速以及有效率。是以，本案之 雙面太陽能電池之製造方法具有極高之實用性，實為一具 產業價值之發明，爰依法提出申請。 ❹ 本案得由熟習此技術之人士任施匠思而為諸般修飾， 然皆不脫如附申請專利範圍所欲保護者。 【圖式簡單說明】 第一圖A-E:係為傳統雙面太陽能電池之製造流程結 構示意圖。 第二圖A-L :係為本案較佳實施例之雙面太陽能電池 之製造流程結構不意圖。 201021221 【主要元件符號說明】 10、 20 :半導體基板 11、 21 :射極層 12、 22 :翁玻璃層 13、 23 :第一抗反射膜 16、 28 :第一電極 14、 25 :背表面電場層 ❿ 15、26:第二抗反射膜 17、 27:第二電極 24 :麵源J| 26a :開口 27a :第二導電材料 28a:第一導電材料 S1 ··第一表面 參 S2 :第二表面The second conductive material 27a of the App 1 embodiment is 18, but the UW is not deposited by the UW with the screen printing technology on the second surface S2, and the sintering step can be performed for the opening of the second surface. The portion at W is the second electrode 27. Then, as shown in the second figure K, gold 201021221 is performed on the first surface S1. · The coating process is performed. In this embodiment, the second conductive material 28a is formed on the first surface S1 by using a screen printing technique. Further, as shown in FIG. 1 , a sintering step is performed to form the first conductive material 28 a on the first surface S1 to form the first electrode 28 , wherein the first electrode 28 passes through the first anti-reflective film 23 and extends Thereby, the emitter layer 21' is used to complete the manufacture of the double-sided solar cell. In summary, the manufacturing method of the double-sided solar cell provided by the present invention mainly utilizes a Group 3A element as a doping source, and uses a screen printing technique or a germanium ore technique to form a doping on the second surface of the double-sided solar cell. The source layer, 藉 can effectively simplify the process by using the doping source and the corresponding manufacturing technology, and can greatly shorten the overall process time, and can further save costs, and can improve the thermal diffusion of boron tribromide in the prior art. The process requires a higher temperature and takes a longer time, resulting in higher manufacturing costs, and can damage the P-type semiconductor substrate and affect the performance of the double-sided solar cell, making the manufacturing process of the double-sided solar cell easier and faster. Efficient. Therefore, the manufacturing method of the double-sided solar cell in this case has extremely high practicability, and is actually an invention of industrial value, and the application is made according to law. ❹ This case has been modified by people who are familiar with this technology, but it is not intended to be protected by the scope of the patent application. [Simple description of the diagram] The first figure A-E: is a schematic diagram of the manufacturing process of a conventional double-sided solar cell. The second drawing A-L is not intended to be a manufacturing process structure of the double-sided solar cell of the preferred embodiment of the present invention. 201021221 [Description of main component symbols] 10, 20: semiconductor substrate 11, 21: emitter layer 12, 22: engeng glass layer 13, 23: first anti-reflection film 16, 28: first electrode 14, 25: back surface electric field Layers 15 and 26: second anti-reflection film 17, 27: second electrode 24: surface source J| 26a: opening 27a: second conductive material 28a: first conductive material S1 · first surface reference S2: second surface