公开(公告)号：GB1195944A

公开(公告)日：1970-06-24

申请号：GB1130068

申请日：1968-03-08

Applicant: IBM

Inventor： HOBBS DAVID EDWARD ,  JONES ARTHUR SCOTT

IPC: H01L21/311

Abstract: 1,195,944. Etching silicon oxide material. INTERNATIONAL BUSINESS MACHINES CORP. 8 March, 1968, No. 11300/68. Heading B6J. [Also in Division H1] Silicon oxide materials, especially of silicon monoxide, are etched by aqueous solutions containing hydrofluoric acid and potassium permanganate at temperatures between 10 and 60‹ C. The solutions preferably contain between 50 and 300 grams/litre of hydrofluoric acid and between 1 and 15 gms./litre of potassium permanganate, optionally in the presence of glacial acetic acid or phosphoric acid. The etohant is particularly useful in the construction of printed circuits, wherein the silicon oxide is coated with a metal layer and a photo-resist which are substantially unaffected by the etchant. In particular, a workpiece, Fig. 1, which comprises a substrate 1 of copper, a layer 2 of chromium, a silicon monoxide layer 3, a copper layer 4 and a photo-resist 5 may be provided with an aperture 6 by washing away the resist 5 in the exposed areas, etching through layer 4 with FeCl 3 , through layer 3 with HF/KMnO 4 and through layer 2 with K 3 Fe(CN) 6 , before electro-deposition of copper therein.