HIGH-RATE SELECTIVE ETCHING OF A-SIH USING HYDROGEN RADICALS

A high-rate selective etching method of hydrogenated amorphous silicon (a-Si:H) using hydrogen radicals is presented. A very high etch rate of 2.7 mum/min was obtained at 50-degrees-C using a microwave hydrogen afterglow method. However, amorphous silicon nitride (a-SiN].2:H), si licon oxide (SiO2), silicon carbide (a-SiCo.5:H), and Al films were no t etched under the same conditions. These results suggest that high-ra te selective etching of a-Si:H can be achieved using hydrogen radicals . This method is suitable for the fabrication of large-area devices.