DRY ETCH PROCESS IN MAGNETIC NEUTRAL LOOP DISCHARGE PLASMA

Magnetic neutral loop discharge (NLD) plasma, which has attractive cha racteristics in terms of plasma production and spatial controllability , was successfully applied to a high-rate etch process with satisfacto ry uniformity, In the application to the SiO2 etch process, an etch ra te of about 1 mu m/min was obtained with C4F8 gas pressure of 0.4 Pa, and the uniformity was better than 3% for the 6-inch wafer. A highly s elective process was achieved by mixing C4F8 with H-2. At a gas flow r atio of H-2/(H-2 + C4F8) x 100 = 65%, the obtained selectivity of SiO2 /Si was higher than 100 and the etch rate of SiO2 was sustained on the order of 800 nm/min, where 13.6 MHz rf power was supplied in the cont inuous wave (CW) mode.