DEFECT ETCH FOR (100) GaAs
Original Publication Date: 1988-Aug-01
Included in the Prior Art Database: 2005-Feb-15
An improved etching method has been proposed for GaAs crystals which provides a sharp delineation of dislocations on (100) surfaces. In the processing of GaAs crystals for semiconductor devices, defect delineation by chemical etching is used as a fast and simple technique for determining crystallographic perfection of individual crystals. A molten KOH and AB etch [*] is frequently used to delineate crystal defects. Molten KOH requires a high temperature processing step and has the added disadvantage of being extremely corrosive. AB etch provides only a weak delineation of dislocations on (100) surfaces. The proposed etch consists of 3 parts CrO3 (3 molal) and 1 part HF (48%) by volume. This particular etch produces a sharp delineation of dislocations with a smooth background. Fig.