MANUFACTURE OF SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To finely process ferroelectric substance or platinum in a semiconductor device easily. SOLUTION: A device insulating film 2 is formed on a semiconductor substrate 1. A lower platinum film 3, a ferroelectric film 4, an upper platinum film 5 and a titanium film 6 are formed, and a desired pattern of photoresist mask 7 is formed thereon. In this case, the thickness of the titanium film 6 is made not less than one-tenth of the sum of the upper platinum film 5, the ferroelectric film 4 and the lower platinum film 3. In a dry etching step, the titanium film 6 is etched and the photoresist mask 7 is removed in an ashing treatment step. With a patterned mask of titanium 6, three laminated layers 3 to 5 are etched using a mixed gas of chlorine and 40vol% of oxygen in a dry etching step. In addition, the titanium film 6 is etched by chlorine gas plasma in the dry etching step.