Inventors:
Robert L. Thornton - East Palo Alto CA
Fernando A. Ponce - Sunnyvale CA
Assignee:
Xerox Corporation - Stamford CT
International Classification:
H01S 319
Abstract:
A buried-layer semiconductor structure solving the problem of defect and dislocation generation which typically results when impurity induced layer disordering occurs across interfaces where there are changes in both the column III and the column V constituents in the manufacture of III-V compound semiconductors, for use, for example, in lasers. The structure is characterized by a thin buried active layers entirely bounded by thick layers on a substrate. Defect generation is avoided by maintaining the thin layer below a critical thickness and lattice matching the thick layers to the substrate. As a further feature, the problem of relatively poor thermal conductivity in AlGaInP based laser structures is avoided by minimizing the amount of AlGaInP material contained in the laser structure, restricting these materials only to the critical active layers, and using AlGaAs for the majority of the optical guiding and carrier confining layers. As a further feature, high levels of p-type doping in AlInP, which is desired because of its low refractive index, is obtained by replacing AlInP layers with AlGaAs layers of high aluminum composition and therefore comparable refractive index.
