Patent ID: 6543107
Filing Date: 2003-04-08
Classification: H01L,Y10S,Y10T

Abstract:
A method for preparing a piezoelectric thin film by a sol-gel process, comprising the steps of:a) coating a substrate with a sol composition comprising a sol, of a metal component, and a polymer compound and then drying the coating to form a film; b) pre-sintering the film to form a porous thin film of gel comprising an amorphous metal oxide; f) repeating the steps a) and b) at least once to form laminated layers of porous thin films comprising the amorphous metal oxide; câ€²) pre-annealing the laminated layers of the porous thin films to convert the laminated layers to a crystalline metal oxide; dâ€²) repeating the steps f) and câ€²) at least once to form laminated films of the crystalline metal oxide; and eâ€²) annealing the films prepared in the step dâ€²) to grow crystal grains of perovskite type in the laminated films into a larger size, wherein this annealing step is carried out in two stages, a first stage of which is carried out at a temperature in a range of from 600 to 800Â° C. with a second stage being carried out at a temperature in a range of from 800 to 1000Â° C.