Abstract: A method of manufacturing a semiconductor device including a substrate; a first nitride layer containing gallium on the substrate; and a second nitride layer containing silicon on the first nitride layer includes generating an etchant of a gas containing chlorine atoms or bromine atoms; and selectively removing the second nitride layer, wherein the etchant is generated by plasma discharge of the gas, wherein the second nitride layer and the first nitride layer are prevented from being irradiated with ultraviolet rays generated at a time of the plasma discharge, and wherein the selectively removing the second nitride layer includes etching the second nitride layer under a first atmosphere at a first pressure that is lower than a first saturated vapor pressure of a silicon compound and that is higher than a second saturated vapor pressure of a gallium compound.

Abstract: A method of manufacturing a semiconductor device including a substrate; a first nitride layer containing gallium on the substrate; and a second nitride layer containing silicon on the first nitride layer includes generating an etchant of a gas containing chlorine atoms or bromine atoms; and selectively removing the second nitride layer, wherein the etchant is generated by plasma discharge of the gas, wherein the second nitride layer and the first nitride layer are prevented from being irradiated with ultraviolet rays generated at a time of the plasma discharge, and wherein the selectively removing the second nitride layer includes etching the second nitride layer under a first atmosphere at a first pressure that is lower than a first saturated vapor pressure of a silicon compound and that is higher than a second saturated vapor pressure of a gallium compound.

Abstract: The present invention relates to a molding die comprising a base portion and a pattern portion having recesses and protrusions provided on a surface of the base portion, wherein a distance between the centers of protruding portions of the pattern portion is 15 to 50 nm, a ratio of recessed and protruding portion (protrusion/distance between centers of the protruding portions) of the pattern portion is 0.5 or less, a height of the protruding portion of the pattern portion is 2 nm or more, and a defect density of the pattern portion is 10×1010 cm2 or less. The present invention also relates to a lens comprising a base portion and a pattern portion having recesses and protrusions provided on a surface of the base portion, wherein a distance between centers of protruding portions of the pattern portion is 15 to 50 nm.