分别以氢氧化钠(NaOH)、碳酸钠(Na2CO3)和磷酸钠(Na3PO4.12H2O)作为刻蚀剂,研究刻蚀浓度、温度(θ)、刻蚀时间(te)和添加剂(异丙醇(IPA)、碳酸氢钠(NaHCO3))对晶体硅表面织构化的影响,用场发射扫描电子显微镜表征织构效果.通过优化工艺,可得到较低的平均表面反射率(Rav),按使用的刻蚀剂分别为:9.70%(NaOH)、9.76%(Na2CO3)和8.63%(Na3PO4.12H2O).据此分析了Rav和织构表面形貌之间的关系.发现添加剂IPA在Na3PO4.12H2O或Na2CO3与NaOH 3种刻蚀剂溶液中均可明显起改善织构效果.NaHCO3在某些方面具有与IPA的相同作用,同时又能促进大金字塔的形成.文中同时初步提出有关刻蚀过程的机理.

The texturization of(100) crystalline silicon(c-Si) wafer was studied by field-emission scanning electron microscope using different kinds of etchant: sodium hydroxide,sodium carbonate and tribasic sodium phosphate.By optimizing the etching parameters,the lowest values of averaged reflectance(Rav) were obtained to be 9.70% for NaOH,9.76% for Na2CO3 and 8.63% for Na3PO4·12H2O,which is comparable to that of the wafer with textured surface covered with an anti-reflection coating of either silicon nitride or thermally grown silicon dioxide.The relation of Rav and surface morphology of textured wafer was analyzed.Moreover,special emphasis was put on the role of isopropyl alcohol(IPA) and sodium bicarbonate for texturization.It is proved that IPA decreased the etching rate but improved the morphology of the textured surface.It seems that played NaHCO3 played the similar role of IPA but resulted in the formation of large pyramid.The mechanism of texturization by different kinds of etchant was suggested.