GaAs太阳电池帽层腐蚀研究──GaAs/AlGaAs薄膜体系的选择性腐蚀  

STUDY ON THE ETCHING TECHNOLOGY OF CAP LAYER OF GaAs SOLAR CELL THE SELECTIVE ETCHING OF THIN FILM SEQUENCES OF GaAs/AlGaAs

作　　者：公延宁[1] 汪乐[1] 莫金玑[1] 夏冠群[1] 

机构地区：[1]中国科学院上海冶金研究所

出　　处：《太阳能学报》1999年第2期109-115,共7页Acta Energiae Solaris Sinica

摘　　要：由ｐ＋－ＧａＡｓ帽层和ｐ－ＡｌｘＧａ１－ｘＡｓ（ｘ＝０·８—０．９）窗口层构成的异质薄膜体系是ＧａＡｓ太阳电池器件中的常规结构。对该异质结构的只腐蚀ＧａＡｓ而不腐蚀ＡｌＧａＡｓ的选择性腐蚀工艺是ＧａＡｓ太阳电池制备过程中的一道关键工序。针对传统腐蚀工艺中出现的腐蚀后露出的ＡｌＧａＡｓ表面呈现彩色的问题，从改进腐蚀液配方角度，围绕通常采用的氨水－双氧水（ＮＨ４ＯＨ－Ｈ２Ｏ２）腐蚀液体系，对该问题作了深入细致的专门研究，并与柠檬酸－双氧水（Ｃ６Ｈ８Ｏ７－Ｈ２Ｏ２）和柠檬酸－柠檬酸钾－双氧水（Ｃ６Ｈ８Ｏ７－Ｋ３Ｃ６Ｈ５Ｏ７－Ｈ２Ｏ２）腐蚀液体系作对比，最终得到了较满意的氨水－双氧水－磷酸（ＮＨ４ＯＨ－Ｈ２Ｏ２－Ｈ３ＰＯ４）新腐蚀液体系。这种腐蚀液体系不仅可在较宽的溶液浓度范围内实现对高Ａｌ组分ＧａＡｓ／ＡｌＧａＡｓ异质结构的选择性腐蚀。The selective etching of GaAs/Al XGa 1-x As(x=0 8～0 9)heterostructure,of which the GaAs solar cell of conventional structure is made,is a key process in the fabrication of solar cell removing the GaAs cap layer everywhere except under the grid lines and exposing the AlGaAs window layer.To solve the problem of colour surface of AlGaAs layer exposed by use of traditional etchant solutions,this paper,on the basis of generally used aqueous ammonia hydrogen peroxide(NH 4OH-H 2O 2)etchant,and by means of improving echant solution ingradients,has done a careful special research to probe into this issue and finally,comparing with citric acid hydrogen peroxide(C 6H 8O 7-H 2O 2)and citric acid potassium citrate hydrogen peroxide(C 6H 8O 7-K 3C 6H 5O 7-H 2O 2)solutions,obtained the relatively satisfactory new etchant of aqueous ammonia hydrogen peroxide phosphoric acid(NH 4OH-H 2O 2-H 3PO 4).This etchant can not only perform selective etching of GaAs/AlGaAs heterostructure with high Al composition in a much broader range of solution concentrations,but also not produce apparent bad effects on the outward appearance of AlGaAs layer exposed.

关 键 词：太阳电池 帽层 窗口层 选择性腐蚀 砷化镓 薄膜 

分 类 号：TM914.4[电气工程—电力电子与电力传动]