Document Type and Number:
Japanese Patent JPS5716736
Kind Code:
B2
Abstract:
1436603 Etching WESTERN ELECTRIC CO Inc 25 Sept 1973 [25 Sept 1972] 44776/73 Heading B6J A structure having a first layer comprising Al x1 Ga 1-x1 As and a second layer adjacent the first layer comprising Al x2 Ga 1-x2 As wherein x 2 > x 1 and the value of x l being from 0-0À25, the value of x 2 being less than unity and x 2 - x 1 # 0À02, is etched in an aqueous solution comprising H 2 O 2 and a source of hydroxyl ions (e.g. NH 4 OH), the pH of the solution being from 6 to 8 so that the first layer is preferentially etched relative to the second layer. As shown a substrate of n-type GaS 10 supports a layer of ntype AlGaAs 11, a layer of n-type GaAs 12 and a layer of p-type AlGaAs 13. The assembly is etched in an aqueous solution of 10-70% by weight H 2 O 2 containing NH 4 OH at solution pH of 7À05 to give preferential attack on layer 12, Fig. 1B.
Application Number:
JP10706073A
Publication Date:
April 07, 1982
Filing Date:
September 25, 1973
Export Citation:
International Classes:
C23F1/00; H01L21/306; H01L21/308; H01L33/00