Patent ID: 7736923
Filing Date: 2010-06-15
Classification: H01L,H01S

Abstract:
1. A method for fabricating an optical semiconductor device including a light emitting section, a photodetector section, and a transistor section, the method comprising the steps of: forming a first conductivity type second semiconductor region directly on a first conductivity type first semiconductor region; forming selectively a first buried layer having the first conductivity type of which impurity concentration is higher than that of the first semiconductor region by ion implantation to a boundary face between the first semiconductor region and the second semiconductor region in a region except the light emitting section; after forming the first buried layer, forming selectively a second buried layer having the second conductivity type by ion plantation to the second semiconductor region, after forming the second buried layer, forming a second conductivity type third semiconductor region in an upper part of the second semiconductor region, where an impurity concentration of the second conductivity type third semiconductor region is lower than that of the second buried layer; forming a photodetector made of the second semiconductor region and the third semiconductor region in the photodetector section; forming selectively a transistor in a region of the second semiconductor region and the third semiconductor region in the transistor section, forming, by forming a trench by performing selective anisotropic etching on a region of the first semiconductor region and the second semiconductor region in the photodetector section, a micro mirror formed of a wall face of the trench; and bonding a semiconductor laser element, which is prepared beforehand in a form of a chip, onto a bottom face of the thus formed trench, wherein the second buried layer is formed in the upper part of the second semiconductor region.