ULTRASONIC ETCHING OF GAAS IN CRO3-HF AQUEOUS-SOLUTIONS

An ultrasonic vibration aided etching technique for revealing dislocat ions in GaAs has been developed. This technique, which employs CrO3-HF aqueous solutions aided by ultrasonic vibration, produces clear etch pit patterns in thinly etched layers of GaAs, without light irradiatio n and agitation, at room temperature. Therefore, this technique is sui table to reveal dislocations in epitaxial layers of GaAs.