Abstract: An etching method includes (a) disposing a substrate having a silicon oxide film on a substrate support in a chamber. The substrate includes a plurality of etching stop layers arranged inside the silicon oxide film. The plurality of etching stop layers are arranged at different positions in a thickness direction of the silicon oxide film. Each of the plurality of etching stop layers is formed of at least one of tungsten and molybdenum. The etching method (b) supplying a processing gas into the chamber, the processing gas including a gas containing at least one of tungsten and molybdenum, a gas containing carbon and fluoride, and an oxygen-containing gas; and (c) generating plasma from the processing gas to etch the silicon oxide film, thereby forming a plurality of recesses that reach the plurality of etching stop layers, respectively, in the silicon oxide film.

Abstract: Disclosed are a light-emitting semiconductor device substrate and a method of manufacturing the same. The substrate is prepared by causing a Ga.sub.1-x Al.sub.x As compound semiconductor single crystalline thick-film layer having a first AlAs mole fraction and a low Al containing and oxidation-delaying Ga.sub.1-y Al.sub.y As compound semiconductor single crystalline thin film serving as a surface protective layer and having a second AlAs mole fraction to be sequentially grown on a GaAs crystal substrate. The method comprises the step of causing the thick-film layer and the thin film to be sequentially grown on the GaAs crystal substrate. The GaAs crystal substrate is removed after sequential epitaxial growth of the thick-film layer and thin film on the GaAs crystal substrate.

Abstract: In a light-emitting semiconductor device of double heterostructure consisting of GaAlAs mixed crystal, a film of Ga.sub.1-y Al.sub.y As having a thickness less than 1 .mu.m is sandwiched in between a p-type clad layer of mixed crystal Ga.sub.1-x1 Al.sub.xl As and an n-type clad layer of mixed crystal Ga.sub.1-z Al.sub.z AS, whereby the wavelength of the emitted light is stabilized, and the thyristor phenomenon is curbed in the n-type clad layer, and at the same time the p-type carrier concentration is increased in the growth layer or in the substrate.