Experimental and theoretical study of the cracking behavior of sol-gel-derived SiO2 film on InP substrate

In this paper, we study and characterize the cracking behavior of a sol-gel -derived amorphous silica film on a InP substrate. The sol-gel silica films are deposited by spin-coating and rapid thermal processing (RTP). It is ob served that the volatility of the III-V semiconductor results in the cracki ng of the films when the annealing temperature is higher than 450 degrees C , and that the crack patterns are all parallel or perpendicular to (100). T he experimental results on the crack patterns in the sol-gel silica films a re then theoretically analyzed. In addition, the critical thicknesses of th e sol-gel films on InP are compared with those deposited on Si.