Mitsubishi Denki Kabushiki Kaisha

Kenzo Mori

Nobuaki Kaneno

Tadashi Kimura

Hitoshi Tada

Tatuya Kimura

Yoshitatu Kawama

Yuji Okura

Hirotaka Kizuki

Masayoshi Takemi

A substrate holder employed for MOCVD and supporting a wafer on which crystal growth proceeds includes a molybdenum holder body, a GaAs polycrystalline film with a flat surface grown on a part of the surface of the molybdenum holder body where the wafer is absent, and an InP polycrystalline film grown on the GaAs polycrystalline film. Each of the polycrystalline films is grown to a thickness of 0.3 .mu.m or more at a temperature higher than the epitaxial growth temperature of 575.degree. C. During the MOCVD process, the emissivity of the molybdenum substrate holder is stable at a value near the emissivity of the wafer on the substrate holder and, therefore, the decomposition ratio of PH.sub.3 gas on the substrate holder is stable at a value near the decomposition ratio on the wafer, whereby any variation of the incorporation ratio of P atoms in the grown InGaAsP, i.e., a variation of the composition of the InGaAsP, is reduced and run-to-run variations of the composition of the grown crystal are reduced.

Substrate holder for MOCVD

A method for fabricating a semiconductor laser includes forming a double heterojunction structure on a first conductivity type semiconductor substrate; forming the double heterojunction structure into a stripe mesa shape by selective etching; successively growing a first conductivity type layer, a second conductivity type current blocking layer, and a first conductivity type current blocking layer on opposite sides of the mesa to embed the mesa; and adding an impurity from a surface of the first conductivity type current blocking layer to form impurity doped regions that electrically separate the second conductivity type current blocking layer from an upper part of the mesa at opposite sides of the mesa.

Method of making semiconductor laser

A semiconductor laser includes a first conductivity type semiconductor substrate; a double-heterojunction structure including a first conductivity type cladding layer, an active layer, and a second conductivity type cladding layer successively disposed on the semiconductor substrate; two parallel stripe grooves forming the double-heterojunction structure in a mesa shape; a first conductivity type mesa embedding layer, a second conductivity type current blocking layer, and a first conductivity type current blocking layer successively disposed on the semiconductor substrate and contacting opposite sides of the mesa; and impurity doped regions formed by adding an impurity through the surface of the first conductivity type current blocking layer. The impurity doped regions electrically separate an upper part of the mesa from the second conductivity type current blocking layer at opposite sides of the mesa. Since the second conductivity type current blocking layer is not in contact with the mesa structure, no leakage current path is formed in the laser structure.

Semiconductor laser

Growing community of inventors

Itami, Japan

Kenzo Mori