Abstract
Silica gel films were deposited on Si wafers by spin-coating using solutions of mole ratios, Si (OC2H5)4: H2O : HNO3: C2H5OH = 1 : x : 0.01: 4 (x=2, 4, 10). The gel films were heated at 10°C min-1, and in situ observation was made using an optical microscope. The cracking onset temperature was found to decrease with increasing H2O content in the starting solutions. The gel films were also heated at 5°C min-1 up to 500°C, and in situ measurement of stress in films were conducted using a thin film stress measurement instrument (FLX-2320, Tencor). In-plane intrinsic stress was tensile, increasing with increasing temperature, irrespective of the H2O content in the starting solutions, while larger stress was found in films prepared from solutions of higher H2O contents.
