Semiconductor laser, semiconductor device, and their manufacture methods

摘要

A substrate is made of SiC. A plurality of AlxGa1-xN patterns (0<=x<=1) is formed on a surface of the substrate and dispersively distributed in an in-plane of the substrate. An AlyGa1-yN buffer layer (0<=y<=1) covers the surface of the substrate and the AlxGa1-xN patterns. A laser structure is formed on the AlyGa1-yN buffer layer. Since the AlGaN buffer layer is grown by using the AlGaN patterns as seed crystals, a dislocation density of a predetermined region in the AlGaN buffer layer can be lowered. The characteristics of a laser structure can be improved by forming the laser structure above the region having a low dislocation density. Since the AlGaN pattern has electric conductivity, the device resistance can be suppressed from being increased.