PROCESS FOR PREPARING SPIN-ON-GLASS COATING-LIQUID

摘要

The pH of tetra alkoxy silane of formula (I) is adjusted below 3.0 by adding acid together with isopropyl alcohol or its solvent mixture, and then coating liquid is prepared by reacting trialkoxy silane of formula (II) and water in a weight ratio of 0.5:1-8:1 for 1-24hrs at 25-90 deg.C, and finally diluting the liquid to have solid content of 5-15wt.%. The mole ratio of H2O/Si in the coating liquid is 1.5-10. In formula, R1 and R2 is C1-C6 alkyl; R3 is H, C1-C6 alkyl or C6-C20 aryl.