Etching Characteristics of Defects in the InGaAsP ‐ InP LPE Layers

Abstract

Defects in the normalInGaAsP‐normalInP multiepitaxial layers on the normalInP (111)P substrate were investigated using chemical etching techniques. Threading dislocations, stacking faults, dislocation rosettes, and dislocation crowds were revealed on normalInP epitaxial layers by the AB etch at 60°C. They were identified from their etch features and it was suggested that dislocation rosettes and crowds were caused by localized mismatch stress.

A Study of Inclusions in Indium Phosphide

“…The work reported here is a detailed study of unusual inclusions in InP. We believe that similar defects have been detected, but not identified as such, by several previous workers (2,3). The occurrence of "precipitate complexes," seen either by transmission x -r a y topography (4,5) or by optical examination of etched {001} and {111} surfaces (6)(7)(8)(9)(10)(11) has been noted, and recently optical and x -r a y topography (XRT) observations of "dislocation clusters" have been presented (12).…”

A Defect Etchant for <100> InGaAsP

“…Chemical etching is the simplest method for revealing dislocations and other defects in crystals. A number of papers have been published recently dealing with chemical, electrochemical, and photochemical etching of InP (7)(8)(9)(10)(11), InGaAs (12,13), and InGaAsP grown on <111> B InP (14,15). However, the <100> orientation is widely utilized for LED's, lasers, and other devices, but no chemical etchant that selectively reveals dislocations in <100> InGaAsP layers has yet been reported.…”