Method of electrochemical-mechanical polishing of silicon carbide wafers

摘要

The subject of the invention is a method of electrochemical-mechanical polishing of silicon carbide wafers, used in electronics, especially for manufacturing diodes and transistors based on SiC in high power and high frequency systems. The method according to the invention consists in that in the 1st stage, a silicon carbide SiC wafer (1) is adhesively fixed on a replaceable insert (4) of a conductive material in a socket of a cassette (3) that does not conduct current and has at least one socket, said cassette (3) being permanently fixed to a polishing holder (2) made of a conductive material, said holder (2) being positioned in the head of an electrochemical-mechanical polishing device and the polishing plate (5) of the polishing device is being lined with a polishing pad (6) for chemical polishing, resistant to aggressive chemical agents, after which the holder is connected with the anode and the polishing pad (6) moistened with an electrolyte layer that enables current flow is connected to the cathode, connecting the electrode outputs with a direct current feeder and electric current is passed through thus prepared system, an then in the 2nd stage, after washing and rinsing, the wafer (1) is placed in the cassette (3) socket again, onto an insert (4) replaced to a non-conductive one, and the wafer is subjected to polishing with colloidal silica, after which the thus obtained the wafer (1) is washed, rinsed with water and dried.