TEXTURING OF MONOCRYSTALLINE SEMICONDUCTOR SUBSTRATES TO REDUCE INCIDENT LIGHT REFLECTANCE

摘要

PROBLEM TO BE SOLVED: To provide a method of reducing oxygen in texturing solutions for silicon wafers to improve incident light absorption.SOLUTION: The method includes providing a solution with a pH of 13 to 14 and with a surface tension of 72 dyn/cmor less including: one or more alkoxylated glycols having a molecular weight of 170 g/mol or greater and a flash point of 75°C or greater; one or more alkaline compounds; and one or more oxygen scavengers in sufficient amounts to reduce oxygen concentration in the solution to 1000 ppb or less. Monocrystalline semiconductor substrates are textured with alkaline solutions to form pyramid structures thereon to reduce incident light reflectance and improve light absorption of the wafers. The alkaline baths include compounds which inhibit the formation of flat areas between the pyramid structures to improve the light absorption.