Thin Solid Films, Vol.517, No.6, 1983-1988, 2009
Stress evolution of sol-gel-derived silica coatings during heating: The effects of the chain length of alcohols as solvents
The effects of the solvent on in-plane stress evolution were studied on sol-gel-derived silica gel coatings during heating. Si(OC(2)H(5))(4)-H(2)O-HNO(3)-ROH (ROH = CH(3)OH, C(2)H(5)OH, n-C(3)H(7)OH, and n-C(4)H(9)OH) solutions were prepared where the mole ratio Si(OC(2)H(5))(4):H(2)O:HNO(3)=1:8:0.01 and the volume ration Si(OC(2)H(5))(4): ROH=1:1.1. Silica gel films were deposited by spin coating on Si (100) wafers 4 in. in diameter, and heated at 5 degrees C/min up to 500 degrees C, where in situ stress measurement was conducted by measuring the substrate curvature. The stress was tensile and increased with increasing temperature. The stress was found 10 be identical below 200 degrees C between the films prepared with different alcohols while the stress above 200 degrees C Was larger in the order n-C(4)H(9)OH