SELECTIVE ETCHING METHOD OF NITRIDE BASE COMPOUND SEMICONDUCTOR, AND SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To make feasible the selective etching of a nitride base semiconductor from underneath a layer by using an etching gas made from the blended gas made from a gas out of a halogen gas and a halogen compound and the second gas made from one gas out of hydrogen gas and an insert gas. ;SOLUTION: After the formation of SiO₂ layer 8 on the entire surface of an n⁺-type GaN layer 7 on a C-surfaced sapphire substrate 1, this SiO₂ layer 8 is patterned in striped shape. For this etching step, e.g. a hydrofluoric acid base etching is used. Next, aperture parts 8a, 8b are formed by etching the SiO₂. Next, after the removable of the SiO₂ layer 8 in a gate electrode forming region, the n⁺-type GaN layer 7 is thermally etched using an etching gas made from a blended gas of HCl and N₂ which contain 10% of HCl. Finally, sidewall spacers 11 are formed on the sidewalls of the n⁺-type GaN layer 6 and the SiO₂ layer 8.;COPYRIGHT: (C)1998,JPO