IMPROVED PROCESS FOR PRODUCING A PLANAR-TYPE SEMICONDUCTOR DEVICE

摘要

1,244,929. Etching. FUJITSU Ltd. 6 Nov., 1969 [28 Nov., 1968], No. 54414/69. Heading B6J. [Also in Division H1] A Cr layer 7, which is itself shaped by etching through a photoresist mask 8, is used as an etching mask to define the shape of a Pt layer 6 on a semi-conductor device, the Cr layer 7 subsequently being removed. In the embodiment a Si body 1 provided with a Pt 5 Si 2 ohmic contact region 4 through a SiO 2 /Si 3 N 4 passivating layer 2/3 has deposited sequentially thereon a Ti layer 5, the Pt layer 6, the Cr layer 7 and the photoresist layer 8. A specified aqueous KOH/KMnO 4 etchant is used to etch the Cr layer 7 and a 3-10:1 by volume HNO 3 /HCl mixture is used to etch the Pt layer 6. An Au layer and an Au beam lead are electrodeposited on to the Pt layer 6 after complete removal of the photoresist 8 and Cr 7. The exposed area of the Ti layer 5 may finally be removed using an H 2 SO 4 /HF etchant.