Texturization of Si(1 0 0) substrates using tensioactive compounds

Random pyramid texturization of Si(1 0 0) substrates in alkaline solutions with addition of surface active compounds is considered. Technological difficulties connected with the application of alcohol additives are analyzed and a new solution for the wet-chemical texturization is proposed. The commonly applied alcohols in the texturization process, such as isopropanol and tertbutanol have been replaced in this work by diols (the alcohols with multiple hydroxyl groups). The results of texturization in KOH solution with 1,2-pentanediol are presented. Optimization of the solution composition and process conditions is performed. Measurements of the coefficient of light reflection carried out in the spectral range from 300 nm to 1200 nm, for the textured substrates with and without an additional anti-reflection layer are presented. The reflection coefficient for the substrates obtained in the optimal etching conditions (1 M KOH + 2% 1,2-pentanediol, 90 °C, 20 min) is close to 10%, which is comparable with the coefficient of light reflection obtained in KOH solutions with isopropyl alcohol addition. Unquestioned advantages of the solutions with diol addition (higher process temperature, shorter etching time, technological improvements) show that they can successfully replace the currently applied solutions.