High-Rate Selective Etching of a-Si:H 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 µm/min was obtained at 50°C using a microwave hydrogen afterglow method. However, amorphous silicon nitride ( a-SiN1.2:H), silicon oxide ( SiO2), silicon carbide ( a-SiC0.5:H), and Al films were not etched under the same conditions. These results suggest that high-rate selective etching of a-Si:H can be achieved using hydrogen radicals. This method is suitable for the fabrication of large-area devices.