Chromium etching characteristics using a planar type plasma reactor

The dry etching characteristics of Cr film in the CCl sub 4 /O sub 2 mixed gas plasma have been investigated with a variety of etching parameters in the planar-type reactor with the 13.56 MHz radiofrequency power. Moreover, the dry etching resistance of EB resists and variation of the feature size on a 12.5 and 15 cm Cr Mask are described. The etch rate of Cr film depends strongly on the etchant gas composition ratio, the electrode separation and the electrode surface materials. In the cathode coupling mode with a gas pressure of 0.2 torr, a gas flow rate of CCl sub 4 /O sub 2 of 0.5, electrode separation of 80 mm and radiofrequency power density of 0.38 W/cm exp 2 , the following results are obtained: the etch rate of Cr film is approx 30 nm/min, whereas that of the EB resist is 15-70 nm/min; the resistance of the polystylene-type resist for the plasma etching is the same or better than that of AZ-1350 photoresist; the standard deviation (3 sigma ) of the Cr feature size within 15 cm Mask is 0.169 mu m.--AA