Patent ID: 9202976
Filing Date: 2015-12-01
Classification: H01L

Abstract:
1. A method for producing a Group III nitride semiconductor light-emitting device, the method comprising: preparing a sapphire substrate having a periodic structure of mesas on a main surface which is a flat plane; forming a low-temperature buffer layer on of the sapphire substrate; and growing a semiconductor layer comprising a Group III nitride semiconductor on the low-temperature buffer layer, wherein each of the mesas has at least one shape selected from a group consisting of a cone, a truncated cone, a hexagonal pyramid, a polygonal pyramid other than the hexagonal pyramid, a hexagonal truncated pyramid, and a polygonal truncated pyramid other than the hexagonal truncated pyramid, including a bottom surface which is a part of the main surface, wherein the periodic structure has a pitch width in a range from 1.0 μm to 3.0 μm, each mesa has a height in a range from 0.5 μm to 3.0 μm, an angle θ between an inclined surface of the mesa and the bottom surface of the mesa is in a range from 40° to 60°, the bottom surface of the mesa has a width in a range from 2 μm to 4 μm, and a shortest distance between the bottom surfaces of two adjacent mesas is in a range from 0.1 μm to 1.0 μm, and wherein the growing the semiconductor layer comprises forming a first semiconductor layer on the low-temperature buffer layer by supplying at least two types of gases including a raw material gas containing a Group III element and a raw material gas containing a Group V element, so as to satisfy following equation: Y: Partial pressure ratio of the raw material gas containing the Group V element to the raw material gas containing the Group III element K: Total area of the main surface including the bottom surface of the mesa S: Area of a flat surface which is an area obtained by subtracting an area of a bottom surface just below the inclined surface of the mesa from the total area K R: Area ratio of the area S to the total area K, thereby suppressing a growth of the first semiconductor layer on the inclined surface of the mesa and promoting a growth of the first semiconductor layer on the flat surface.