Title :
Selective wet etching of GaAs on Al0.24Ga0.76As for GaAs/Al0.24Ga0.76As/In0.22Ga0.78 As PHEMT
Author :
Lee, Jong-Lam ; Moon, Eun-A ; Oh, Jung-Woo ; Ryu, Seong Wook ; Yoo, Hyung Mo
Author_Institution :
Dept. of Mater. Sci. & Eng., Pohang Univ. of Sci. & Technol., South Korea
fDate :
11/9/2000 12:00:00 AM
Abstract :
A selective etching solution of GaAs over Al0.24Ga0.76As, composed of acid-buffer solution (citric acid monohydrate+potassium citrate) and H2O2 has been developed for GaAs/Al0.24Ga0.76As/In0.22Ga0.78 As PHEMT applications. The best selectivity of 776 was achieved using the mixed solution (citric acid-buffer solution:H2O2=5:1). The etch rate of GaAs in the solution is as low as 46.6 Å/s. Both the low etch rate of GaAs and the high selectivity exhibit the standard deviation of pinch-off voltage of 1.0 μm-gate PHEMTs as low as ±0.029 V across a 3 in wafer. This demonstrates the applicability of this solution to the gate recess process
Keywords :
III-V semiconductors; aluminium compounds; etching; gallium arsenide; high electron mobility transistors; indium compounds; reaction rate constants; surface chemistry; 1.0 mum; 3 in; Al0.24Ga0.76As; GaAs; GaAs-Al0.24Ga0.76As-In0.22Ga 0.78As; GaAs/Al0.24Ga0.76As/In0.22Ga 0.78As PHEMT; H2O selectivity; acid-buffer solution; citric acid monohydrate; citric acid-buffer solution; etch rate; gate recess process; low etch rate; pinch-off voltage; potassium citrate; selective etching solution; selective wet etching; standard deviation;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:20001337
