A conventional method for manufacturing a Pb(Zr,Ti)O3 (hereinafter, referred to as “PZT”) film will be explained.
On a 4-inch wafer, a Pt film (111)-oriented, for example, is formed, and on the Pt film, a PZT sol-gel solution is spin-coated by a spin coater. Next, the coated PZT sol-gel solution is heated and held on a hot plate to be dried, and the moisture is removed. After that, it is furthermore heated and held on a hot plate kept at higher temperature to be calcined. The repetition of the process a plurality of times generates amorphous PZT.
Next, the amorphous PZT having been calcined is subjected to an annealing treatment by using a pressurizing-type lamp annealing device (RTA: rapidly thermal anneal) and PZT crystallization is performed. The crystallized PZT film has a perovskite structure. (For example, see Patent Document 1)
On the other hand, PZT has the Tc existing at 300° C. or higher, and has good ferroelectric properties and piezoelectric properties, but in circumstances where the whole industrial world aims at making lead free, the problem to be solved is to attain lead-free PZT.
USPTO Backgrounds
USPTO Backgrounds