因此，本發明的ㄧ個目的在提供一種結晶矽晶圓的紋理蝕刻液組成物，可以於在其表面上提供一種微型錐體結構時最小化結晶矽晶圓表面上一個範圍內的紋理品質變異，因而改善光吸收的效能。
本發明的另ㄧ個目的在提供一種結晶矽晶圓的紋理蝕刻液組成物而無需應用曝氣製程以及於紋理化時使用額外的蝕刻液成分。
本發明的另ㄧ個目的在提供一種結晶矽晶圓的紋理蝕刻液組成物，其具有顯著減少所使用量的優點，因而比起習用的紋理蝕刻液組成物，增多了處理的片數。
此外，本發明的又ㄧ個目的在提供一種使用前面矽晶圓紋理蝕刻液的紋理蝕刻方法。
為達成上面的目的，本發明提供下列所述。
(1) 一種結晶矽晶圓的紋理蝕刻液組成物，包含0.1至20重量百分比的鹼性化合物；0.000001至1重量百分比的至少一種表面活性劑，該表面活性劑選自於由聚氧乙烯 (POE) 化合物、一種聚氧丙烯(POP)化合物及其共聚物所組成的群組；以及作為剩餘部分的水。
(2) 根據上面(1)的組成物，該組成物尚包含0.1至50重量百分比的環狀化合物。
(3) 根據上面(2)的組成物，該環狀化合物具有攝氏100度或更高的沸點。
(4) 根據上面(1)的組成物，該鹼性化合物是選自於由氫氧化鉀、氫氧化鈉、氫氧化銨、四羥甲基銨以及四羥乙基銨所組成的群組中的至少ㄧ者。
(5) 根據上面(1)的組成物，表面活性劑是選自下述所組成的群組中的至少其中之一：聚氧乙二醇、聚氧乙二醇甲醚、聚氧乙烯單烯丙基醚、聚氧乙烯新戊基醚、聚乙二醇單(三苯乙烯基苯基)醚、聚氧乙烯十六烷基醚、聚氧乙烯月桂基醚、聚氧乙烯油基醚、聚氧乙烯硬脂醯基醚、聚氧乙烯十三烷基基醚、聚氧乙烯癸基醚、聚氧乙烯辛基醚、聚氧乙烯雙酚-A醚、聚氧乙烯甘油醚、聚氧乙烯壬基苯基醚、聚氧乙烯苄基醚、聚氧乙烯苯醚(phenylether)、聚氧乙烯辛基苯基醚、聚氧乙烯酚醚、在烷基中具有六至三十個碳原子之聚氧乙烯烷基環己醚、聚氧乙烯的β-萘基醚、聚氧乙烯篦麻醚、聚氧乙烯氫化篦麻醚、聚氧乙烯月桂酯、聚氧乙烯氫化硬脂酯、聚氧乙烯油烯基酯、聚氧乙烯月桂基、聚氧乙烯硬脂基胺、聚氧乙烯牛脂胺、聚丙二醇、聚氧乙烯-聚氧丙烯共聚物、聚氧乙烯-聚氧丙烯癸基醚共聚物、聚氧乙烯-聚氧丙烯十一烷基醚共聚物、聚氧乙烯-聚氧丙烯十二烷基醚共聚物、聚氧乙烯-聚氧丙烯十四烷基醚共聚物、聚氧乙烯-聚氧丙烯2-乙基己醚共聚物、聚氧乙烯-聚氧丙烯月桂基醚共聚物、聚氧乙烯-聚氧丙烯硬脂醯基醚共聚物、甘油添加聚氧乙烯-聚氧丙烯共聚物、乙二胺附加的聚氧乙烯-聚氧丙烯共聚物。
(6) 根據上面(2)的組成物，環狀化合物是選自下述所組成的群組中的至少其中之一：哌嗪、N-甲基哌嗪、N-乙基哌嗪、羥乙基哌嗪、N-(2-氨基乙基)哌嗪、N- N’二甲基哌嗪、嗎啉、N-甲基嗎啉、N-乙基嗎啉、N-苯基嗎啉、N-椰油基嗎啉、N-（2-氨基乙基）嗎啉、N-（2 - 氰乙基）嗎啉、N-（2 - 羥乙基）嗎啉、N-（2 - 羥丙基）嗎啉、N-乙醯基嗎啉、N-甲醯嗎啉、N-甲基嗎啉-N-氧化物；甲基吡啶、N-甲基哌啶、3,5 - 二甲基哌啶、N-乙基哌啶、N-（2 - 羥乙基）哌啶；N-甲基-4 - 哌啶酮、N-乙烯基-2 - 哌啶酮、N-甲基吡咯烷、N-甲基吡咯烷酮、N-乙基-2 - 吡咯烷酮、N-異丙基-2 - 吡咯烷酮、N-丁基-2 - 吡咯烷酮、N-叔丁基-2 - 吡咯烷酮、N-己基-2 - 吡咯烷酮、N-辛基-2 - 吡咯烷酮、N-芐基-2 - 吡咯烷酮、N-環己基-2 - 吡咯烷酮、N-乙烯基-2 - 吡咯烷酮、N-（2 - 羥乙基）-2 - 吡咯烷酮、N-（2 - 甲氧基乙基）-2 - 吡咯烷酮、N-（2 - 甲氧基丙基）-2 - 吡咯烷酮、N-（2 - 乙氧基乙基）-2 - 吡咯烷酮；N-甲基咪唑啶酮、二甲基咪唑啶酮、N-（2 - 羥乙基）- 亞乙基脲；四氫呋喃、四氫糠醇；N-甲基苯胺、N-乙基苯胺、N,N-二甲基苯胺、N-（2 - 羥乙基）苯胺、N，N-雙 - （2 - 羥乙基）苯胺、N-乙基-N-（2 - 羥乙基）苯胺；N，N-二乙基鄰甲基苯胺、N-乙基-N-（2 - 羥乙基）間甲苯胺；二甲基芐胺；γ-丁內酯、甲苯基三唑、1,2,3 - 苯並三唑、1,2,3 - 三唑、1,2,4 - 三唑、3 - 氨基-1,2,4 - 三唑、4 - 氨基-4H-1,2,4 - 三唑、1 - 羥基苯並三唑、1 - 甲基苯並三唑、2 - 甲基苯並三唑、5 - 甲基苯並三唑、苯並三唑-5 - 羧酸、硝基苯並三唑，以及2 - （2H-苯並三唑-2 - 基）-4,6 - 二 - 叔丁基苯酚。
(7)根據上面(1)的組成物，組成物尚包含0.000001至1重量百分比的至少ㄧ種氟表面活性劑，該氟表面活性劑選自於由：全氟烷基羧酸、全氟烷基磺酸、全氟烷基硫酸、全氟烷基磷酸酯、全氟烷基胺鹽、全氟烷基季銨鹽、全氟烷基羧基甜菜鹼、全氟烷基磺基甜菜鹼、氟代烷基聚氧乙烯及全氟烷基聚氧乙烯所組成的群組，每一者在其每一烷基具有一至三十個碳原子。
(8) 根據上面(1)的組成物，組成物尚包含至少ㄧ種矽化合物，該矽化合物選自於由：細二氧化矽粉末；以Na2O穩定的一種膠體二氧化矽溶液；以K2O穩定的一種膠體二氧化矽溶液；以酸性溶液穩定的一種膠體二氧化矽溶液；以NH3穩定的一種膠體二氧化矽溶液；以至少一有機溶劑穩定的一種膠體二氧化矽溶液，該至少一有機溶劑選自於由乙醇、丙醇、乙二醇、甲基乙基酮、甲基異丁基酮所組成的群組；液體矽酸鈉；液態矽酸鉀；以及液態矽酸鋰。
(9) 一種結晶矽晶圓的紋理蝕刻方法包含：將結晶矽晶圓浸入根據上面(1)至(8)項任一項的蝕刻液組成物中、噴塗組成物於其上、或將矽晶圓浸入組成物中然後噴塗組成物於其上。
(10) 根據上面(9)的方法，所述浸入、噴塗，或浸入及噴塗係在攝氏50至100度的溫度中進行30秒至60分鐘。
根據本發明的結晶矽晶圓的紋理蝕刻液組成物可以最小化結晶矽晶圓表面上一個範圍內的紋理品質變異，繼而，改善紋理的均勻性，以增大太陽能的吸收同時減小光反射，從而增大發光的效能。
此外，在紋理化時無須增加額外的蝕刻液成分，藉之改善生產力並獲致成本方面的經濟優勢。
又，如果另外包含有高沸點的環狀化合物，與現存的紋理蝕刻液組成物比較，則處理的片數會大大的增加，且無需再使用任何額外的蝕刻液成分，因而獲致生產力與成本上的優勢。
另外，由於根據本發明的紋理蝕刻方法不需使用任何替代的曝氣裝置，其達成初始生產與製程成本方面的經濟優勢且亦可形成均勻的微型錐體結構。Accordingly, it is an object of the present invention to provide a textured etchant composition for a crystalline germanium wafer that minimizes texture variation in a range on the surface of a crystalline germanium wafer while providing a micro-cone structure on its surface. , thus improving the efficiency of light absorption.
Another object of the present invention is to provide a textured etchant composition for a crystalline germanium wafer without the use of an aeration process and the use of additional etchant composition for texturing.
Another object of the present invention is to provide a textured etchant composition for a crystalline germanium wafer that has the advantage of significantly reducing the amount used, thereby increasing the number of wafers processed compared to conventional texture etchant compositions.
Moreover, it is a further object of the present invention to provide a texture etching method using the front tantalum wafer texture etchant.
In order to achieve the above object, the present invention provides the following.
(1) A textured etching solution composition of a crystalline germanium wafer comprising 0.1 to 20 weight percent of a basic compound; 0.000001 to 1 weight percent of at least one surfactant selected from the group consisting of polyoxyethylene ( POE) a group of compounds, a polyoxypropylene (POP) compound and copolymers thereof; and water as the remainder.
(2) The composition according to the above (1), which further contains 0.1 to 50% by weight of a cyclic compound.
(3) According to the composition of the above (2), the cyclic compound has a boiling point of 100 ° C or higher.
(4) The composition according to the above (1), which is selected from the group consisting of potassium hydroxide, sodium hydroxide, ammonium hydroxide, tetramethylolmonium, and tetrahydroxyethylammonium. At least the best.
(5) The composition according to the above (1), wherein the surfactant is at least one selected from the group consisting of polyoxyethylene glycol, polyoxyethylene glycol methyl ether, and polyoxyethylene single Allyl ether, polyoxyethylene neopentyl ether, polyethylene glycol mono(tristyrylphenyl) ether, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether , polyoxyethylene stearyl decyl ether, polyoxyethylene tridecyl ether, polyoxyethylene decyl ether, polyoxyethylene octyl ether, polyoxyethylene bisphenol-A ether, polyoxyethylene glyceryl ether, poly Oxyethylene nonylphenyl ether, polyoxyethylene benzyl ether, phenylether, polyoxyethylene octyl phenyl ether, polyoxyethylene phenol ether, having six to thirty carbons in the alkyl group Atom polyoxyethylene alkyl cyclohexyl ether, polyoxyethylene beta-naphthyl ether, polyoxyethylene ricinole, polyoxyethylene hydrogenated castor ether, polyoxyethylene lauryl ester, polyoxyethylene hydrogenated stearyl ester, Polyoxyethylene oleyl ester, polyoxyethylene lauryl, polyoxyethylene stearylamine, polyoxyethylene tallow amine, polypropylene glycol, polyoxyethylene-polyoxypropylene copolymer, Polyoxyethylene-polyoxypropylene decyl ether copolymer, polyoxyethylene-polyoxypropylene undecyl ether copolymer, polyoxyethylene-polyoxypropylene lauryl ether copolymer, polyoxyethylene-polyoxypropylene Tetradecyl ether copolymer, polyoxyethylene-polyoxypropylene 2-ethylhexyl ether copolymer, polyoxyethylene-polyoxypropylene lauryl ether copolymer, polyoxyethylene-polyoxypropylene stearyl sulfonate copolymer A polyoxyethylene-polyoxypropylene copolymer and an ethylenediamine-added polyoxyethylene-polyoxypropylene copolymer are added to the glycerin.
(6) The composition according to the above (2), wherein the cyclic compound is at least one selected from the group consisting of piperazine, N-methylpiperazine, N-ethylpiperazine, hydroxy Ethyl piperazine, N-(2-aminoethyl)piperazine, N-N' dimethylpiperazine, morpholine, N-methylmorpholine, N-ethylmorpholine, N-phenylmorpholine , N-cocoylmorpholine, N-(2-aminoethyl)morpholine, N-(2-cyanoethyl)morpholine, N-(2-hydroxyethyl)morpholine, N-(2- Hydroxypropyl)morpholine, N-ethinylmorpholine, N-methylmorpholine, N-methylmorpholine-N-oxide; picoline, N-methylpiperidine, 3,5 - II Methylpiperidine, N-ethylpiperidine, N-(2-hydroxyethyl) piperidine; N-methyl-4-piperidone, N-vinyl-2-piperidone, N-methyl Pyrrolidine, N-methylpyrrolidone, N-ethyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-butyl-2-pyrrolidone, N-tert-butyl-2-pyrrolidone, N-hexyl -2 - pyrrolidone, N-octyl-2-pyrrolidone, N-benzyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-(2-hydroxyethyl) -2 - pyrrolidone, N-(2 - Methoxyethyl)-2 -pyrrolidone, N-(2-methoxypropyl)-2-pyrrolidone, N-(2-ethoxyethyl)-2-pyrrolidone; N-methylimidazolidone , dimethylimidazolidinone, N-(2-hydroxyethyl)-ethylene urea; tetrahydrofuran, tetrahydrofurfuryl alcohol; N-methylaniline, N-ethylaniline, N,N-dimethylaniline, N-(2-hydroxyethyl)aniline, N,N-bis-(2-hydroxyethyl)aniline, N-ethyl-N-(2-hydroxyethyl)aniline; N,N-diethyl ortho Methylaniline, N-ethyl-N-(2-hydroxyethyl) m-toluidine; dimethylbenzylamine; γ-butyrolactone, tolyltriazole, 1,2,3-benzotriazole, 1,2,3 -triazole, 1,2,4-triazole, 3-amino-1,2,4-triazole, 4-amino-4H-1,2,4-triazole, 1-hydroxybenzene And triazole, 1-methylbenzotriazole, 2-methylbenzotriazole, 5-methylbenzotriazole, benzotriazole-5-carboxylic acid, nitrobenzotriazole, and 2 - (2H-benzotriazol-2-yl)-4,6-di-tert-butylphenol.
(7) The composition according to the above (1), the composition further comprising 0.000001 to 1% by weight of at least an antimony fluorosurfactant selected from the group consisting of: perfluoroalkyl carboxylic acid, perfluoroalkane Sulfonic acid, perfluoroalkylsulfuric acid, perfluoroalkyl phosphate, perfluoroalkylamine salt, perfluoroalkyl quaternary ammonium salt, perfluoroalkylcarboxybetaine, perfluoroalkylsulfobetaine, fluorine The group consisting of alkyl polyoxyethylene and perfluoroalkyl polyoxyethylene each having from one to thirty carbon atoms per alkyl group.
(8) The composition according to the above (1), the composition further comprising at least an antimony compound selected from the group consisting of: fine cerium oxide powder; a colloidal cerium oxide solution stabilized by Na 2 O; a colloidal cerium oxide solution stabilized by K 2 O; a colloidal cerium oxide solution stabilized by an acidic solution; a colloidal cerium oxide solution stabilized by NH 3 ; a colloidal cerium oxide solution stabilized by at least one organic solvent, The at least one organic solvent is selected from the group consisting of ethanol, propanol, ethylene glycol, methyl ethyl ketone, methyl isobutyl ketone; liquid sodium citrate; liquid potassium citrate; and liquid citric acid lithium.
(9) A texture etching method for a crystalline germanium wafer comprising: dipping a crystalline germanium wafer into an etching liquid composition according to any one of (1) to (8) above, spraying a composition thereon, or placing a crucible thereon The wafer is immersed in the composition and the composition is sprayed thereon.
(10) According to the method of (9) above, the immersion, spraying, or immersion and spraying are carried out at a temperature of 50 to 100 degrees Celsius for 30 seconds to 60 minutes.
The textured etchant composition of the crystalline germanium wafer according to the present invention can minimize texture quality variations over a range of crystalline germanium wafer surfaces, and in turn, improve texture uniformity to increase solar absorption while reducing light reflection , thereby increasing the efficiency of the light.
In addition, there is no need to add additional etchant composition during texturing to improve productivity and achieve economic advantages in terms of cost.
Moreover, if a high-boiling cyclic compound is additionally contained, the number of processed sheets is greatly increased as compared with the existing textured etching liquid composition, and no additional etching liquid component is required, resulting in productivity and cost. The advantages.
In addition, since the texture etching method according to the present invention does not require the use of any alternative aeration device, it achieves an economic advantage in terms of initial production and process cost and can also form a uniform micro-cone structure.
本發明是關於一種結晶矽晶圓的紋理蝕刻液組成物以及使用該組成物將結晶矽晶圓紋理蝕刻的方法。
本發明的詳細說明如下文。
本發明的結晶矽晶圓的紋理蝕刻液組成物包括：一種鹼性化合物；至少一種表面活性劑，其選自由一種聚氧乙烯(POE)化合物、一種聚氧丙烯(POP)化合物及其共聚物所組成的群組；以及水。
更特別的，其較佳包括0.1至20重量百分比的鹼性化合物；0.000001至1重量百分比的至少一種表面活性劑，其選自由一種聚氧乙烯(POE)化合物、一種聚氧丙烯(POP)化合物及其共聚物所組成的群組；以及作為剩餘部分的水。
又，本發明的結晶矽晶圓的紋理蝕刻液組成物除了：鹼性化合物；至少一種表面活性劑，其選自於由一種聚氧乙烯(POE)化合物、一種聚氧丙烯(POP)化合物及其共聚物所組成的群組；以及水以外，可更包括一種環狀化合物。
更特別的，其較佳包括：0.1至20重量百分比的鹼性化合物；0.1至50重量百分比的環狀化合物；0.000001至1重量百分比的至少一種表面活性劑，其選自於由一種聚氧乙烯(POE)化合物、一種聚氧丙烯(POP)化合物及其共聚物所組成的群組；以及作為剩餘部分的水。
鹼性化合物是蝕刻結晶矽晶圓表面的成分且此等成分的種類並無特別限制。例如，氫氧化鉀、氫氧化鈉、氫氧化銨、四羥甲基銨、四羥乙基銨等均可被使用。這些化合物可被單獨使用或以其中的二種或更多種結合使用。
相對於共100 wt.％用於結晶矽晶圓的紋理蝕刻液化合物，可以0.1至20重量百分比的量包括鹼性化合物，且較佳為1至5重量百分比。當鹼性化合物的含量是在前面的範圍內時，可以進行蝕刻矽晶圓的表面。
環狀化合物所指的化合物包括：一種環狀碳氫化合物含有4至10個碳原子；具有4至10個碳原子的雜環碳氫化合物，其包括選自氮、氧或硫的至少一雜原子，其可改善結晶矽晶圓表面的潤濕性以避免鹼性化合物造成的過度蝕刻，因而最小化紋理的品質變異，且同時，可迅速減少蝕刻產生的氫氣泡數量故而避免氣泡腔的發生。此外，由於其具有高沸點，與傳統技藝中習用的異丙醇相較，可以相對小的量使用上述材料，並且使用相同量的組成物處理的片數可增加。
本案使用的環狀化合物較佳具有不低於攝氏100度的高沸點，更佳的是在攝氏150至400度的範圍的沸點。
環狀化合物的種類無特別限制只要其沸點不低於攝氏100度，且可包括，例如，哌嗪、嗎啉、吡啶、哌啶、哌啶酮、吡咯烷、吡咯烷酮、咪唑啶酮、呋喃、苯胺、甲苯胺以及內酯化合物。這些特別的例子包括：哌嗪、N-甲基哌嗪、N-乙基哌嗪、羥乙基哌嗪、N-（2 - 氨基乙基）哌嗪、N,N'-二甲基哌嗪；嗎啉、N-甲基嗎啉、N-乙基嗎啉、N-苯基嗎啉、N-椰油基嗎啉、N-（2 - 氨基乙基）嗎啉、N-（2 –氰乙基）嗎啉、N-（2–羥乙基）嗎啉、N-（2–羥丙基）嗎啉、N-乙醯基嗎啉、N-甲醯嗎啉、N-甲基嗎啉-N-氧化物；甲基吡啶、甲基哌啶、3,5-二甲基哌啶、N-乙基哌啶、N-（2–羥乙基）哌啶；N-甲基-4-哌啶酮、N-乙烯基-2-哌啶酮；N-甲基-吡咯烷、N-甲基吡咯烷酮、N-乙基-2-吡咯烷酮、N-異丙基-2-吡咯烷酮、N-丁基-2-吡咯烷酮、N-叔丁基-2-吡咯烷酮、N-己基-2-吡咯烷酮、N-辛基-2-吡咯烷酮、N-芐基-2-吡咯烷酮、N-環己基-2-吡咯烷酮、N-乙烯基-2-吡咯烷酮、N-(2-羥乙基)-2-吡咯烷酮、N-(2-甲氧基乙基)-2-吡咯烷酮、N-(2-甲氧基丙基)-2-吡咯烷酮、N-(2-乙氧基乙基)-2-吡咯烷酮；N-甲基咪唑啶酮、二甲基咪唑啶酮、N-(2-羥乙基)-亞乙基脲；四氫呋喃、四氫糠醇；N-甲基苯胺、N-乙基苯胺、N,N-二甲基苯胺、N-(2-羥乙基)苯胺、N,N-雙-(2-羥乙基)苯胺、N-乙基-N-(2-羥乙基)苯胺；N,N-二乙基鄰甲基苯胺、N-乙基-N-(2-羥乙基)間甲苯胺、二甲基芐胺；γ-丁內酯、甲苯基三唑、1,2,3-苯並三唑、1,2,3-三唑、1,2,4-三唑、3-氨基-1,2,4-三唑、4-氨基-1,2,4-三唑、1-羥基苯並三唑、1-甲基苯並三唑、2-甲基苯並三唑、5-甲基苯並三唑、苯並三唑-5-羧酸、硝基苯並三唑、2-(2H-苯並三唑-2-基)-4,6-二-叔丁基苯酚，或類似者，這些可被單獨使用或以其中的二者或多者結合使用。
相對於共100 wt.％用於結晶矽晶圓的紋理蝕刻溶液組成物，可以0.1至50 wt.％(更佳為2至10 wt.％)的量包括環狀化合物。在上面含量的範圍，矽晶圓表面的濕潤性被有效改善而最小化紋理的品質變異因而提高紋理的均勻性。
本發明可以其最理想的含量包括一種表面活性劑，特別是，可選擇性地使用基於含羥基化合物的表面活性劑，例如一種聚氧乙烯(POE)化合物、一種聚氧丙烯(POP)化合物及其共聚物。
基於聚氧乙烯(POE)化合物、聚氧丙烯(POP)化合物及其共聚物的表面活性劑控制了紋理蝕刻液組成物中的氫氧根離子[OH-]的活性，而減小Si100與Si111方向之間的蝕刻率的差異，因而增大以同樣組成物量所能處理的片數。另外，藉由改善結晶矽晶圓表面的濕潤性而快速減小蝕刻時產生的氫氣泡量，可避免氣泡腔的發生，藉此減少紋理化期間一個範圍內的紋理品質變異，從而提高紋理的均勻性以及改善晶圓的外觀。
聚氧乙烯(POE)表面活性劑可包括，例如，聚氧乙二醇、聚氧乙二醇甲醚、聚氧乙烯單烯丙基醚、聚氧乙烯新戊基醚、聚氧乙二醇單(三苯乙烯基苯基)醚、聚氧乙烯十六烷基醚、聚氧乙烯月桂基醚、聚氧乙烯油烯基醚、聚氧乙烯硬脂醯基醚、聚氧乙烯十三烷基醚、聚氧乙烯癸基醚、聚氧乙烯辛基醚、聚氧乙烯雙酚-A醚、聚氧乙烯甘油醚、聚氧乙烯壬基苯基醚、聚氧乙烯苄基醚、聚氧乙烯苯基醚、聚氧乙烯辛基苯基醚、聚氧乙烯酚醚、在烷基中具有六至三十個碳原子的聚氧乙烯烷基環己醚、聚氧乙烯的β-萘基醚、聚氧乙烯篦麻醚、聚氧乙烯氫化篦麻醚；聚氧乙烯月桂酯、聚氧乙烯硬脂醯基酯、聚氧乙烯油烯基酯；氧乙烯月桂基胺、聚氧乙烯硬脂醯胺、聚氧乙烯牛脂胺，或類似物。同時，聚氧丙烯(POP)表面活性劑可包括，例如，聚丙二醇。又，聚氧乙烯(POE)化合物及聚氧丙烯(POP)化合物的共聚物可包括，例如，聚氧乙烯-聚氧丙烯共聚物、聚氧乙烯-聚氧丙烯癸基醚共聚物、聚氧乙烯-聚氧丙烯十四烷基醚共聚物、聚氧乙烯-聚氧丙烯十一烷基醚共聚物、聚氧乙烯-聚氧丙烯十二烷基醚共聚物、聚氧乙烯-聚氧丙烯2-乙基己醚共聚物、聚氧乙烯-聚氧丙烯月桂基醚共聚物、聚氧乙烯-聚氧丙烯硬脂醯基醚共聚物、甘油加成聚氧乙烯-聚氧丙烯共聚物、乙二胺加成的聚氧乙烯-聚氧丙烯共聚物，以及諸如此類，這些可單獨使用或以其中的二者或更多者結合使用。
相對於共100重量百分比用於結晶矽晶圓的紋理蝕刻液組成物，自由聚氧乙烯(POE)化合物、聚氧丙烯(POP)化合物及其共聚物所組成的群組中選出來的至少一表面活性劑較佳是以0.000001至1重量百分比的量被包括在其中，更佳為0.00001至0.1之重量百分比且，最佳為0.0001至0.1重量百分比。於上面含量的範圍內，在矽晶圓表面一個範圍內的紋理品質變異可於蝕刻時被減小，晶圓的外觀可被改善，以及可增多以相同量的組成物能處理的片數。
本發明結晶矽晶圓的紋理蝕刻液組成物，除了選自由聚氧乙烯(POE)化合物、聚氧丙烯(POP)化合物及其共聚物所組成的群組中的的至少一種表面活性劑以外，可更包括一種氟表面活性劑。
氟表面活性劑與上述聚氧化合物一起減小蝕刻液組成物的表面張力而更促進改善結晶矽晶圓的表面濕潤度，從而避免鹼性化合物造成的過度蝕刻。
氟表面活性劑的種類並無特別限制，但可包括，例如：陰離子表面活性劑；例如全氟烷基羧酸、全氟烷基磺酸、全氟烷基硫酸、氟烷基磷酸酯等；陽離子表面活性劑，例如全氟烷基胺鹽、全氟烷基季銨鹽等；兩性表面活性劑，例如全氟烷基羧基甜菜鹼、全氟烷基磺基甜菜鹼等；以及非離子型表面活性劑，例如氟代烷基聚氧乙烯及全氟醇聚氧乙烯等，這些化合物的每一者在其每一烷基具有一至三十個碳原子。這些材料亦可被單獨使用或以其中的二者或更多者結合使用。
相對於共100重量百分比用於結晶矽晶圓的紋理蝕刻液組成物，氟表面活性劑可以0.000001至1重量百分比(較佳為0.00001至0.1的重量百分比，以及更佳為0.0001至0.1重量百分比)的量被包括在結晶矽晶圓的紋理蝕刻液組成物中。於上面含量的範圍內，矽晶圓表面的濕潤度可被有效改善。
本發明結晶矽晶圓的紋理蝕刻液組成物尚可包括一種含矽化合物。
含矽化合物係一種可被物理吸附於結晶矽晶圓的表面而作用為一遮罩的成分，因而可使結晶矽晶圓的表面有一微型錐體形式。
含矽化合物可包括粉末、膠體溶液型式或液相矽酸鹽化合物，或類似物。更特別的是，細二氧化矽粉末；以Na2O穩定的一種膠體二氧化矽溶液；以K2O穩定的一種膠體二氧化矽溶液；以酸性溶液穩定的一種膠體二氧化矽溶液；以NH3穩定的一種膠體二氧化矽溶液；使用至少一有機溶劑穩定的一種膠體二氧化矽溶液，該至少一有機溶劑選自於由乙醇、丙醇、乙二醇、甲基乙基酮及甲基異丁基酮所組成的群組；液體矽酸鈉；液態矽酸鉀以及液態鋰矽酸鹽，等等。這些可被單獨或以其中的二者結合使用。
相對於共100重量百分比用於結晶矽晶圓的紋理蝕刻液組成物，可以0.00001至10 重量百分比(較佳為0.0001至1 重量百分比)的量包含含矽化合物。在上面含量範圍內，微型錐體可被容易地形成在結晶矽晶圓的表面上。
結晶矽晶圓的紋理蝕刻液組成物尚包括水作為共100重量百分比（的組成物）的剩餘部分。
水分的種類無特別限制，但較佳是去離子水，且更佳的是用於半導體製程的具有18MΩ/cm或更高之特定電阻的去離子水。
本發明的結晶矽晶圓紋理蝕刻液組成物，其包括上面的成分，可特別以最理想的含量使用至少一種表面活性劑(其選自於由在最佳含量範圍之一種聚氧乙烯(POE)化合物、聚氧丙烯(POP)化合物及其共聚物所組成的群組)以及環狀化合物，以最小化結晶矽晶圓表面上一個範圍內之紋理品質變異，並提高該紋理的均勻性。因而，太陽能吸收被最大化同時光反射被減小，而提高光的效能。另外，顯著減少的所使用組成物的量可增多處理的片數。此外於蝕刻時不需導入替代性的蝕刻液成分，因而獲致生產力與製程成本的優勢。
根據本發明的結晶矽晶圓紋理蝕刻液組成物，可適於用在常用的蝕刻製程，例如浸沒、噴塗、崁入式蝕刻等等。
本發明提供一種使用上述結晶矽晶圓紋理蝕刻液組成物的結晶矽晶圓紋理蝕刻方法。
結晶矽晶圓的紋理蝕刻方法可包括將結晶矽晶圓浸入結晶矽晶圓紋理蝕刻液組成物中、噴塗組成物，或將結晶矽晶圓浸入其中時同時噴塗。
浸入及/或噴塗的次數可無特別的限制且，在同時進行浸入與噴塗時，其操作的順序亦可無限制。
浸入、噴塗或浸入與噴塗可在攝氏50至100度進行30秒至60分鐘。
如上所述，根據本發明之結晶矽晶圓的紋理蝕刻方法不需使用額外的曝氣設備供應氧氣，因此，在起始生產和製程成本上是經濟的且甚至能以簡單的方法形成均勻的微型錐體結構。
下文參酌實例與對照實例將說明較佳具體實例以更具體地了解本發明。但熟悉此項技藝者會明白這些具體實例是供作說明性的目的，且在不違反本發明之範圍與精神下可做各種修改與變化，且這些修改與變化充分地包含在如附申請專利範圍所定義的本發明中。
實例
實例1至27
藉由混合2重量百分比的氫氧化鉀(KOH)、0.016重量百分比的聚氧乙烯苄基醚(PBE)、0.016重量百分比的全氟烷基磷酸酯(PFAS)以及作為剩餘部分的去離子蒸餾水，製備出實例1的結晶矽晶圓紋理蝕刻液組成物。
根據上述的同樣程序，使用表1所列的成分以其相應的量(重量百分比)製備出實例2至27的每一種結晶矽晶圓紋理蝕刻液組成物。
表1
對照實例1至10
根據如實例1所述的相同程序，在對照實例1至10每一者的每一結晶矽晶圓紋理蝕刻液組成物是使用表2所列的成分以其相應的量(重量百分比)所製備。
表2
實驗實例1
藉由下述程序將每個根據實例1至11及對照實例1至6製備的單結晶矽晶圓的紋理蝕刻液組成物，進行紋理蝕刻效果的評估，其結果被顯示於下面表3。
-- 在80℃將單結晶矽晶圓基板浸沒於所製備的單結晶矽晶圓的紋理蝕刻液組成物二十分鐘。
(1)紋理均勻性
經由數位相機以及3D光學顯微鏡來視覺地觀察於紋理蝕刻後在單結晶矽晶圓基板的表面上形成的紋理變異，亦即，均勻性，並根據下面的評估標準做評估。在此處，變色是指當溫度上升至紋理處理溫度時由於隨時間自變異，而無需紋理測試。
<評估標準>
◎錐體形成遍及整個晶圓基板。
○錐體未形成在晶圓基板的一部分(錐體未形成的程度低於5%)。
△錐體未形成在晶圓基板的一部分(錐體未形成的程度為5%至50%)。
×錐體未形成在晶圓基板的一部分(錐體未形成的程度不低於90%)。
(2)錐體平均尺寸()
於紋理蝕刻後獲得的單結晶矽晶圓基板上形成的微型錐體的尺寸是用掃描型電子顯微鏡(SEM)測量。在此處，於測量出形成在一個單位區域上的微型錐體的尺寸後，所測量值的平均被計算及標示出來。
(3) 平均反射(百分比)
當具有400至800nm波長範圍的光被輻射在紋理蝕刻後獲致的單結晶矽晶圓基板的表面上時，使用UV光譜儀決定平均反射率。
表3
如表3所示，經確認當使用根據本發明實例1至11中每一者的紋理蝕刻液組成物來對基板進行紋理蝕刻時，形成在單結晶矽晶圓基板表面上的微型錐體顯示出在微型錐體一個範圍內的減小的品質變異，及達成了極佳的均勻性，並且具有低光反射與增大的光效能。上述紋理蝕刻液組成物包括：一種鹼性化合物；至少一種表面活性劑，其選自於由一種聚氧乙烯(POE)化合物、聚氧丙烯(POP)化合物及其共聚物所組成的群組；以及水。又，經確認，當氟表面活性劑也被加入時，蝕刻液組成物有減小的表面張力且復可促進改善結晶矽晶圓表面的潤濕性，因而避免鹼性化合物的過度蝕刻。
第1圖是一個3D光學顯微鏡影像，其顯示使用實例1製備的紋理蝕刻液組成物作紋理蝕刻的結晶矽晶圓的表面；以及第2圖是一個掃描型電子顯微鏡影像，其顯示經紋理蝕刻的結晶矽晶圓的表面。結果，可以看到微形錐體形成遍及晶圓的表面因而減小了品質變異而增大了紋理均勻性。
另ㄧ方面，在使用對照實例1沒有聚氧化合物為基礎的表面活性劑的紋理蝕刻液組成物的情況下，發生了氫氧化鉀造成的矽過度蝕刻而使得錐體隨意形成遍及晶圓的表面上。又，當使用包含過量聚氧化合物為基礎的表面活性劑的紋理蝕刻液組成物時，蝕刻率會降低而造成無椎體形成。
在對照實例3的紋理蝕刻液組成物中，由於組成物所含異丙醇(IPA)的低沸點，當紋理處理期間繼續使用組成物時，發生了溫度梯度而造成紋理失敗及增加成本。
與本發明的實例比較，在對照實例4的蝕刻液組成物顯示出紋理均勻性與光反射的特性顯著減小。
此外，在對照實例5和6每一者中的紋理蝕刻液組成物於溫度升高至紋理處理的溫度時顯示蝕刻液組成物隨時間而自變異。
實驗實例2
對於上述實例12至27與對照實例3至10每一者中所分別製備的單結晶矽晶圓的紋理蝕刻液組成物，紋理蝕刻效果是用實驗實例1所述的相同方法做評估。此外，工作能力是分別用根據實例13與對照實例7至10的紋理蝕刻液組成物做評估。評估結果如表4與5所示。
(4)工作能力(即將處理的片數)
使用實例13與對照實例7至10的各紋理蝕刻液組成物來紋理蝕刻單結晶矽晶圓基板，並調查使用相同量的組成物的處理片數。在此處，參照根據實例13的處理片數，分別計算出對照實例7至10中每一者的處理片數，以及基於被計算出的數量評估工作能力。
<評估標準>
◎, ○：與實例13相同的處理片數。
△：少於實例13百分之5至百分之10的處理片數。
×：少於實例13高於百分之10的處理片數。
表4
表5
如表4與5所示，當使用本發明實例12至27每一者中的紋理蝕刻液組成物來紋理蝕刻單結晶矽晶圓時，減小了單結晶矽晶圓表面形成的微型錐體的一個範圍內的品質變異而達成極佳的均勻性，減少光反射而改善光效能，且以相同量的組成物處理的片數增加，從而獲致極佳的工作能力，上述紋理蝕刻液組成物以最理想含量包括：一種鹼性化合物；至少一種表面活性劑，其選自於由聚氧乙烯(POE)化合物、聚氧丙烯(POP)化合物及其共聚物所組成的群組；以及水。
由於在上述每一實例的紋理蝕刻液組成物尚包括一種環狀化合物，與既存的紋理蝕刻液組成物比較，發現處理的片數可被大大的增多。又經確認在蝕刻時不再需要使用額外的蝕刻液成分，因而獲致生產力與成本的優勢。
又，由於在上述每一實例的紋理蝕刻液組成物尚包括一種氟表面活性劑，經發現組成物顯示減小的表面張力，而更促進了改善結晶矽晶圓表面的潤濕性，因而避免了鹼性化合物引起的過度蝕刻。
第3圖是一個3D光學顯微鏡影像，其顯示使用實例12製備的紋理蝕刻液組成物作紋理蝕刻的結晶矽晶圓的表面；第4圖是一個掃描型電子顯微鏡影像，其顯示經紋理蝕刻的結晶矽晶圓的表面。從這些圖式，可以看到微形錐體被形成遍及整個晶圓的表面而減小了品質變異，同時改善了紋理均勻性。
另ㄧ方面，在對照實例7與9中，其中以聚氧化合物為基礎的表面活性劑或環狀化合物的含量未在本發明界定的範圍內，與本發明的實例比較，以相同量組成物處理的片數被減少且工作能力變的相當低劣，雖然在矽表面的微型錐體的結構形成良好。此外，在對照實例8與10中，用鹼性化合物的矽蝕刻率顯著下降而錐體形成不佳。
至於對照實例3中的紋理蝕刻液組成物，由於在蝕刻液組成物中所含的異丙醇(IPA)的低沸點，於紋理化時繼續使用該組成物時，發生了溫度梯度而造成紋理失敗及增加成本。
至於在對照實例4中的紋理蝕刻液組成物，與本發明的實例比較，在紋理均勻性與光反射率方面於溫度上升至紋理化的溫度時顯示了顯著減小的特性。
在對照實例5和6中的紋理蝕刻液組成物顯示當溫度升高至紋理化的溫度時蝕刻液組成物會隨時間而發生自變異。The present invention relates to a textured etchant composition for a crystalline germanium wafer and a method of etching a crystalline germanium wafer texture using the composition.
A detailed description of the invention follows.
The texture etching liquid composition of the crystalline germanium wafer of the present invention comprises: a basic compound; at least one surfactant selected from the group consisting of a polyoxyethylene (POE) compound, a polyoxypropylene (POP) compound and a copolymer thereof The group formed; and water.
More particularly, it preferably comprises from 0.1 to 20% by weight of a basic compound; from 0.000001 to 1% by weight of at least one surfactant selected from a polyoxyethylene (POE) compound, a polyoxypropylene (POP) compound a group consisting of its copolymer; and water as the remainder.
Further, the texture etching liquid composition of the crystalline germanium wafer of the present invention comprises: a basic compound; at least one surfactant selected from the group consisting of a polyoxyethylene (POE) compound, a polyoxypropylene (POP) compound, and A group consisting of copolymers thereof; and water, may further comprise a cyclic compound.
More particularly, it preferably comprises: 0.1 to 20 weight percent of a basic compound; 0.1 to 50 weight percent of a cyclic compound; 0.000001 to 1 weight percent of at least one surfactant selected from a polyoxyethylene a group of (POE) compounds, a polyoxypropylene (POP) compound and copolymers thereof; and water as the remainder.
The basic compound is a component which etches the surface of the crystallization wafer and the kind of these components is not particularly limited. For example, potassium hydroxide, sodium hydroxide, ammonium hydroxide, tetramethylolmonium chloride, tetrahydroxyethylammonium or the like can be used. These compounds may be used singly or in combination of two or more of them.
The basic etchant compound may be included in an amount of 0.1 to 20% by weight, and preferably 1 to 5% by weight, based on a total of 100 wt.% of the texture etchant compound for crystallizing the ruthenium wafer. When the content of the basic compound is within the foregoing range, the surface of the ruthenium wafer can be etched.
The compound referred to by the cyclic compound includes: a cyclic hydrocarbon having 4 to 10 carbon atoms; a heterocyclic hydrocarbon having 4 to 10 carbon atoms, which includes at least one selected from nitrogen, oxygen or sulfur. Atom, which improves the wettability of the surface of the crystalline germanium wafer to avoid excessive etching caused by the alkaline compound, thereby minimizing the quality variation of the texture, and at the same time, can rapidly reduce the number of hydrogen bubbles generated by the etching, thereby avoiding the occurrence of bubble chambers. . Further, since it has a high boiling point, the above materials can be used in a relatively small amount as compared with the conventionally used isopropanol, and the number of sheets treated with the same amount of the composition can be increased.
The cyclic compound used in the present invention preferably has a high boiling point of not lower than 100 ° C, and more preferably a boiling point in the range of 150 to 400 ° C.
The kind of the cyclic compound is not particularly limited as long as its boiling point is not lower than 100 degrees Celsius, and may include, for example, piperazine, morpholine, pyridine, piperidine, piperidone, pyrrolidine, pyrrolidone, imidazolidinone, furan, Aniline, toluidine and lactone compounds. These particular examples include: piperazine, N-methylpiperazine, N-ethylpiperazine, hydroxyethylpiperazine, N-(2-aminoethyl)piperazine, N,N'-dimethylperazine Pyrazine; morpholine, N-methylmorpholine, N-ethylmorpholine, N-phenylmorpholine, N-cocoylmorpholine, N-(2-aminoethyl)morpholine, N-(2 - cyanoethyl)morpholine, N-(2-hydroxyethyl)morpholine, N-(2-hydroxypropyl)morpholine, N-ethylmercaptomorpholine, N-methylmorpholine, N-methyl morpholine-N-oxide; picoline, methylpiperidine, 3,5-dimethylpiperidine, N-ethylpiperidine, N-(2-hydroxyethyl)piperidine; N-A 4-piperidone, N-vinyl-2-piperidone; N-methyl-pyrrolidine, N-methylpyrrolidone, N-ethyl-2-pyrrolidone, N-isopropyl-2- Pyrrolidone, N-butyl-2-pyrrolidone, N-tert-butyl-2-pyrrolidone, N-hexyl-2-pyrrolidone, N-octyl-2-pyrrolidone, N-benzyl-2-pyrrolidone, N-ring Hexyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-(2-hydroxyethyl)-2-pyrrolidone, N-(2-methoxyethyl)-2-pyrrolidone, N-(2- Methoxypropyl)-2-pyrrolidone, N-(2-ethoxyethyl)-2-pyrrolidine N-methylimidazolidinone, dimethylimidazolidinone, N-(2-hydroxyethyl)-ethylene urea; tetrahydrofuran, tetrahydrofurfuryl alcohol; N-methylaniline, N-ethylaniline, N , N-dimethylaniline, N-(2-hydroxyethyl)aniline, N,N-bis-(2-hydroxyethyl)aniline, N-ethyl-N-(2-hydroxyethyl)aniline; N,N-Diethyl o-methylaniline, N-ethyl-N-(2-hydroxyethyl) m-toluidine, dimethylbenzylamine; γ-butyrolactone, tolyltriazole, 1,2 , 3-benzotriazole, 1,2,3-triazole, 1,2,4-triazole, 3-amino-1,2,4-triazole, 4-amino-1,2,4-tri Azole, 1-hydroxybenzotriazole, 1-methylbenzotriazole, 2-methylbenzotriazole, 5-methylbenzotriazole, benzotriazole-5-carboxylic acid, nitrobenzene And triazole, 2-(2H-benzotriazol-2-yl)-4,6-di-tert-butylphenol, or the like, these may be used alone or in combination of two or more of them. .
The cyclic compound may be included in an amount of 0.1 to 50 wt.% (more preferably 2 to 10 wt.%) with respect to a total of 100 wt.% of the texture etching solution composition for crystallizing the germanium wafer. In the above range of content, the wettability of the surface of the wafer is effectively improved to minimize the quality variation of the texture and thus improve the uniformity of the texture.
The present invention may include a surfactant in an optimum amount thereof, and in particular, a surfactant based on a hydroxyl group-containing compound, such as a polyoxyethylene (POE) compound, a polyoxypropylene (POP) compound, and Its copolymer.
Surfactants based on polyoxyethylene (POE) compounds, polyoxypropylene (POP) compounds and copolymers thereof control the activity of hydroxide ions [OH - ] in the texture etching solution composition, and reduce Si 100 and The difference in etching rate between the Si 111 directions, thus increasing the number of sheets that can be handled with the same composition amount. In addition, by improving the wettability of the surface of the crystallization wafer, the amount of hydrogen bubbles generated during etching can be quickly reduced, and the occurrence of bubble chambers can be avoided, thereby reducing texture quality variation within a range during texturing, thereby improving texture. Uniformity and improved wafer appearance.
The polyoxyethylene (POE) surfactant may include, for example, polyoxyethylene glycol, polyoxyethylene glycol methyl ether, polyoxyethylene monoallyl ether, polyoxyethylene neopentyl ether, polyoxyethylene glycol. Mono(tristyrylphenyl)ether, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, polyoxyethylene tridecane Ether, polyoxyethylene decyl ether, polyoxyethylene octyl ether, polyoxyethylene bisphenol-A ether, polyoxyethylene glyceryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene benzyl ether, polyoxygen Ethylene phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene phenol ether, polyoxyethylene alkyl cyclohexyl ether having six to thirty carbon atoms in the alkyl group, β-naphthyl group of polyoxyethylene Ether, polyoxyethylene ricinole, polyoxyethylene hydrogenated castor ether; polyoxyethylene lauryl ester, polyoxyethylene stearyl phthalate, polyoxyethylene oleyl ester; oxyethylene laurylamine, polyoxyethylene hard Lipidamine, polyoxyethylene tallow amine, or the like. Meanwhile, the polyoxypropylene (POP) surfactant may include, for example, polypropylene glycol. Further, a copolymer of a polyoxyethylene (POE) compound and a polyoxypropylene (POP) compound may include, for example, a polyoxyethylene-polyoxypropylene copolymer, a polyoxyethylene-polyoxypropylene decyl ether copolymer, polyoxygen. Ethylene-polyoxypropylene tetradecyl ether copolymer, polyoxyethylene-polyoxypropylene undecyl ether copolymer, polyoxyethylene-polyoxypropylene lauryl ether copolymer, polyoxyethylene-polyoxypropylene 2-ethylhexyl ether copolymer, polyoxyethylene-polyoxypropylene lauryl ether copolymer, polyoxyethylene-polyoxypropylene stearyl hydroxy ether copolymer, glycerin addition polyoxyethylene-polyoxypropylene copolymer, Ethylenediamine-added polyoxyethylene-polyoxypropylene copolymers, and the like, these may be used singly or in combination of two or more thereof.
At least one selected from the group consisting of a free polyoxyethylene (POE) compound, a polyoxypropylene (POP) compound, and a copolymer thereof, relative to a total of 100 weight percent of the texture etching liquid composition used for the crystalline germanium wafer The surfactant is preferably included in an amount of 0.000001 to 1% by weight, more preferably 0.00001 to 0.1% by weight, and most preferably 0.0001 to 0.1% by weight. Within the above range of content, texture quality variations over a range of the wafer surface can be reduced during etching, the appearance of the wafer can be improved, and the number of sheets that can be processed with the same amount of composition can be increased.
The texture etching liquid composition of the crystalline germanium wafer of the present invention, except for at least one surfactant selected from the group consisting of polyoxyethylene (POE) compounds, polyoxypropylene (POP) compounds and copolymers thereof, A fluorosurfactant may also be included.
The fluorosurfactant together with the above polyoxygen compound reduces the surface tension of the etchant composition and further promotes the improvement of the surface wettability of the crystallization wafer, thereby avoiding excessive etching by the alkaline compound.
The kind of the fluorosurfactant is not particularly limited, but may include, for example, an anionic surfactant; for example, a perfluoroalkylcarboxylic acid, a perfluoroalkylsulfonic acid, a perfluoroalkylsulfuric acid, a fluoroalkyl phosphate, or the like; Cationic surfactants such as perfluoroalkylamine salts, perfluoroalkyl quaternary ammonium salts, etc.; amphoteric surfactants such as perfluoroalkylcarboxybetaine, perfluoroalkylsulfobetaine, etc.; and nonionic Surfactants, such as fluoroalkylpolyoxyethylene and perfluoroalcohol polyoxyethylene, etc., each of these compounds have from one to thirty carbon atoms per alkyl group. These materials may also be used singly or in combination of two or more of them.
The fluorosurfactant may be 0.000001 to 1 weight percent (preferably 0.00001 to 0.1 weight percent, and more preferably 0.0001 to 0.1 weight percent) relative to a total of 100 weight percent of the texture etchant composition used to crystallize the ruthenium wafer. The amount is included in the texture etchant composition of the crystalline germanium wafer. The wettability of the surface of the tantalum wafer can be effectively improved within the range of the above content.
The textured etchant composition of the crystalline germanium wafer of the present invention may further comprise a cerium-containing compound.
The ruthenium containing compound is a component that can be physically adsorbed onto the surface of the crystallization wafer to act as a mask, thereby allowing the surface of the crystallization wafer to have a micro-cone form.
The cerium-containing compound may include a powder, a colloidal solution type or a liquid phase citrate compound, or the like. More particularly, a fine cerium oxide powder; a colloidal cerium oxide solution stabilized by Na 2 O; a colloidal cerium oxide solution stabilized by K 2 O; a colloidal cerium oxide solution stabilized with an acidic solution; a colloidal cerium oxide solution stabilized by NH 3 ; a colloidal cerium oxide solution stabilized with at least one organic solvent selected from the group consisting of ethanol, propanol, ethylene glycol, methyl ethyl ketone and a group consisting of isobutyl ketone; liquid sodium citrate; liquid potassium citrate and liquid lithium silicate, and the like. These can be used alone or in combination of the two.
The cerium-containing compound may be contained in an amount of 0.00001 to 10% by weight (preferably 0.0001 to 1% by weight) with respect to a total of 100% by weight of the texture etching liquid composition for crystallization of the cerium wafer. Within the above content range, a micro-cone can be easily formed on the surface of the crystalline germanium wafer.
The textured etchant composition of the crystalline germanium wafer also includes water as the remainder of a total of 100 weight percent (composition).
The type of moisture is not particularly limited, but is preferably deionized water, and more preferably deionized water having a specific resistance of 18 M?/cm or higher for a semiconductor process.
The crystalline germanium wafer texture etchant composition of the present invention comprises the above ingredients, and at least one surfactant (which is selected from a polyoxyethylene (POE) in an optimum content range can be used in an especially desirable amount. a compound, a group of polyoxypropylene (POP) compounds and copolymers thereof, and a cyclic compound to minimize texture quality variations over a range of crystalline germanium wafer surfaces and to improve the uniformity of the texture. Thus, solar absorption is maximized while light reflection is reduced, improving light performance. In addition, the significantly reduced amount of the composition used can increase the number of sheets processed. In addition, there is no need to introduce an alternative etchant composition during etching, resulting in productivity and process cost advantages.
The crystalline germanium wafer texture etchant composition according to the present invention can be suitably used in conventional etching processes such as immersion, spray coating, immersion etching, and the like.
The present invention provides a crystalline germanium wafer texture etching method using the above crystalline germanium wafer texture etching solution composition.
The texture etching method of the crystalline germanium wafer may include dipping the crystalline germanium wafer into the crystalline germanium wafer texture etching solution composition, spraying the composition, or simultaneously spraying the crystalline germanium wafer while dipping therein.
The number of times of immersion and/or spraying may be not particularly limited, and the order of operation may be unlimited without immersion and spraying.
Immersion, spraying or immersion and spraying can be carried out at 50 to 100 degrees Celsius for 30 seconds to 60 minutes.
As described above, the texture etching method of the crystalline germanium wafer according to the present invention does not require the use of an additional aeration device to supply oxygen, and therefore, is economical in initial production and process cost and can even form a uniform method in a simple manner. Miniature cone structure.
Preferred embodiments will be described in more detail below with reference to examples and comparative examples to more specifically understand the present invention. However, those skilled in the art will understand that the specific examples are for illustrative purposes, and various modifications and changes can be made without departing from the scope and spirit of the invention. The scope is defined in the invention.
Example Examples 1 to 27
By mixing 2 weight percent potassium hydroxide (KOH), 0.016 weight percent polyoxyethylene benzyl ether (PBE), 0.016 weight percent perfluoroalkyl phosphate (PFAS), and as the remainder of the deionized distilled water, A crystalline germanium wafer texture etchant composition of Example 1 was prepared.
Each of the crystalline germanium wafer texture etchant compositions of Examples 2 to 27 was prepared in accordance with the same procedure as described above using the ingredients listed in Table 1 in their respective amounts (percent by weight).
Table 1
Comparative Examples 1 to 10
According to the same procedure as described in Example 1, each of the crystallization wafer texture etchant compositions of each of Comparative Examples 1 to 10 was prepared using the components listed in Table 2 in their respective amounts (% by weight). .
Table 2
Experimental example 1
The texture etching liquid composition of each of the single crystal germanium wafers prepared according to Examples 1 to 11 and Comparative Examples 1 to 6 was evaluated by the following procedure, and the results of the texture etching were evaluated. The results are shown in Table 3 below.
-- The single crystal germanium wafer substrate was immersed in the textured etchant composition of the prepared single crystal germanium wafer at 80 ° C for twenty minutes.
(1) Texture uniformity The texture variation, that is, uniformity, formed on the surface of a single crystal germanium wafer substrate after texture etching was visually observed by a digital camera and a 3D optical microscope, and evaluated according to the following evaluation criteria. . Here, discoloration refers to self-variation over time when the temperature rises to the texturing temperature without the need for texture testing.
<Evaluation criteria>
◎The cone is formed throughout the entire wafer substrate.
o The cone is not formed on a portion of the wafer substrate (the extent to which the cone is not formed is less than 5%).
The delta cone is not formed on a portion of the wafer substrate (the cone is not formed to a degree of 5% to 50%).
The cone is not formed on a part of the wafer substrate (the extent of the pyramid is not formed to be not less than 90%).
(2) Average cone size ( )
The size of the micro-cone formed on the single-crystal germanium wafer substrate obtained after the texture etching was measured by a scanning electron microscope (SEM). Here, after measuring the size of the micro-cone formed on one unit area, the average of the measured values is calculated and indicated.
(3) Average reflection (percentage)
When light having a wavelength range of 400 to 800 nm is irradiated on the surface of the single crystal germanium wafer substrate obtained after texture etching, the average reflectance is determined using a UV spectrometer.
table 3
As shown in Table 3, it was confirmed that the micro-cone display formed on the surface of the single-crystal germanium wafer substrate when the substrate was subjected to texture etching using the texture etching liquid composition according to each of Examples 1 to 11 of the present invention. Reduced quality variation within a range of micro-cones, and achieves excellent uniformity with low light reflection and increased light efficiency. The texture etchant composition includes: a basic compound; at least one surfactant selected from the group consisting of a polyoxyethylene (POE) compound, a polyoxypropylene (POP) compound, and a copolymer thereof; And water. Further, it has been confirmed that when a fluorosurfactant is also added, the etchant composition has a reduced surface tension and recombination promotes improvement of the wettability of the surface of the crystallization wafer, thereby avoiding excessive etching of the basic compound.
Figure 1 is a 3D optical microscope image showing the surface of a textured etched wafer using the textured etchant composition prepared in Example 1; and Figure 2 is a scanning electron microscope image showing texture etched The surface of the crystalline germanium wafer. As a result, it can be seen that the micro-cone is formed throughout the surface of the wafer, thereby reducing quality variations and increasing texture uniformity.
On the other hand, in the case of using the texture etching liquid composition of the surfactant of Comparative Example 1 without a polyoxyl compound-based surfactant, excessive etch of cesium caused by potassium hydroxide occurs, so that the cone is randomly formed over the surface of the wafer. on. Also, when a texture etching liquid composition containing a surfactant based on an excess of polyoxygen compound is used, the etching rate is lowered to cause no vertebral body formation.
In the texture etchant composition of Comparative Example 3, due to the low boiling point of the isopropyl alcohol (IPA) contained in the composition, when the composition was continuously used during the texture treatment, a temperature gradient occurred to cause texture failure and increase cost.
The etching liquid composition of Comparative Example 4 showed a significant decrease in texture uniformity and light reflection characteristics as compared with the example of the present invention.
Furthermore, the texture etchant composition in each of Comparative Examples 5 and 6 showed that the etchant composition self-mutated over time as the temperature rose to the temperature of the texturing treatment.
Experimental example 2
For the texture etchant composition of the single crystal germanium wafer prepared separately in each of the above Examples 12 to 27 and Comparative Examples 3 to 10, the texture etching effect was evaluated in the same manner as described in Experimental Example 1. Further, the working ability was evaluated by the texture etching liquid compositions according to Example 13 and Comparative Examples 7 to 10, respectively. The evaluation results are shown in Tables 4 and 5.
(4) Working ability (number of pieces to be processed)
The single crystal germanium wafer substrate was texture-etched using each of the texture etching liquid compositions of Example 13 and Comparative Examples 7 to 10, and the number of processed sheets using the same amount of the composition was investigated. Here, with reference to the number of processed sheets according to Example 13, the number of processed sheets of each of Comparative Examples 7 to 10 was calculated, and the working ability was evaluated based on the calculated number.
<Evaluation criteria>
◎, ○: The same number of processed sheets as in Example 13.
△: less than 5 to 10 percent of the number of processed sheets of Example 13.
×: Less than the number of processed sheets of Example 13 higher than 10%.
Table 4
table 5
As shown in Tables 4 and 5, the micro-cone formed on the surface of the single-crystal germanium wafer was reduced when the single-crystal germanium wafer was texture-etched using the texture etchant composition in each of Examples 12 to 27 of the present invention. A range of quality variations to achieve excellent uniformity, reduced light reflection and improved light efficiency, and increased number of sheets treated with the same amount of composition, resulting in excellent workability, the above-described texture etching solution composition The most desirable content comprises: a basic compound; at least one surfactant selected from the group consisting of polyoxyethylene (POE) compounds, polyoxypropylene (POP) compounds and copolymers thereof; and water.
Since the texture etchant composition of each of the above examples further includes a cyclic compound, the number of sheets treated can be greatly increased as compared with the existing texture etchant composition. It has also been confirmed that no additional etchant composition is required during etching, resulting in productivity and cost advantages.
Moreover, since the texture etchant composition of each of the above examples further includes a fluorosurfactant, it is found that the composition exhibits a reduced surface tension, which further promotes the improvement of the wettability of the surface of the crystallization wafer, thereby avoiding Excessive etching caused by basic compounds.
Figure 3 is a 3D optical microscope image showing the surface of a textured etched wafer using the textured etchant composition prepared in Example 12; and Figure 4 is a scanning electron microscope image showing texture etched Crystallize the surface of the wafer. From these patterns, it can be seen that the micro-cones are formed throughout the surface of the wafer to reduce quality variations while improving texture uniformity.
On the other hand, in Comparative Examples 7 and 9, wherein the content of the polyoxyl compound-based surfactant or cyclic compound is not within the scope of the present invention, the composition is the same amount as compared with the examples of the present invention. The number of sheets processed is reduced and the working ability becomes quite inferior, although the structure of the micro-cone on the surface of the crucible is well formed. Further, in Comparative Examples 8 and 10, the ruthenium etching rate with the basic compound was remarkably lowered and the pyramid formation was poor.
As for the texture etching liquid composition in Comparative Example 3, due to the low boiling point of isopropanol (IPA) contained in the etching liquid composition, when the composition was continuously used during texturing, a temperature gradient occurred to cause texture. Failure and increased costs.
As for the texture etchant composition in Comparative Example 4, compared with the example of the present invention, a significantly reduced characteristic was exhibited in terms of texture uniformity and light reflectance at a temperature rise to a textured temperature.
The texture etchant composition in Comparative Examples 5 and 6 showed that the etchant composition self-mutated over time as the temperature rose to the textured temperature.