Selective etching of Al sub(x)Ga sub(1-x)As and In(Al sub(x)Ga sub(1-x))As alloys in succinic acid-hydrogen peroxide solutions

• Published in: Journal of the Electrochemical Society Vol. 140; no. 5; pp. L82 - L83
• Main Authors: Tang, A J, Sadra, K, Streetman, B G
• Format: Journal Article
• Language: English
• Published: 01.01.1993
• ISSN: 0013-4651

Succinic acid-hydrogen peroxide solutions were used to etch Al sub(x)Ga sub(1-x)As and In(Al sub(x)Ga sub(1-x))As alloys, and the etch rates were investigated with the varying alloy mole fractions. It was found that Al sub(x)Ga sub(1-x)As (x less than or approximate to 0.4) may be selectively etched over Al sub(y)Ga sub(1-y)As (y greater than or approximate to 0.5), with a selectivity better than 150. Extended surface exposure to air was found to affect the etch rates, most interestingly for Al sub(0.4)Ga sub(0.6)As. In the In(Al sub(x)Ga sub(1-x))As system, alloys with x less than or approximate to 0.8 can be preferentially etched over In sub(0.52)Al sub(0.48)As with a selectivity of better than 20.