| 摘要 |
PROBLEM TO BE SOLVED: To provide a dry etching method superior in workability in the formation of high dielectric capacity, which forms a lower electrode where platinum is used in a recessed area, and to provide a capacity forming method using the dry etching method. SOLUTION: A platinum film 509 is removed by a process for depositing a first insulating film 504 constituted of SiO2 on a semiconductor substrate 501 and a second insulating film 505 constituted of SiN on the film, a process for forming the first insulating film and the second insulating film in a recessed part 506, a process for depositing platinum films 507 and 509 on the first and second insulating films including the inner part of the recessed part, a process for depositing a third insulating film 508 constituted of SiO2 on the platinum film, a process for exposing the platinum film 509 in an area except for the recessed area, and a process for dry-etching the platinum film 509 by using Ar, Cl2, O2 mixed gas where (O2/(O2+Cl2) flow rate ratio) is 40% and [(Ar flow rate)/(Ar+Cl2+O2) total gas flow rate] is 33%. |
