The earliest reference I know about is: Buckling of Thermally-Grown SiO2 Thin Films, C.W. Wilmsen, E.G. Thompson, and G.H. Meisner, IEEE Trans. Elec. Dev., Jan 1972, p. 122. Yes, they do work if they are small enough. Signed: Hal Jerman, Ph.D., EG&G IC Sensors phone: 408-955-1211 Director of Technology fax: 408-434-6687 1701 McCarthy Blvd, Milpitas, CA 95035