Title :
InAlAs/InGaAs/InP MODFET´s with uniform threshold voltage obtained by selective wet gate recess
Author :
Tong, M. ; Nummila, K. ; Ketterson, Andrew ; Adesida, Ilesanmi ; Caneau, C. ; Bhat, Rajaram
Author_Institution :
Dept. of Electr. & Comput. Eng., Illinois Univ., Urbana, IL, USA
Abstract :
Excellent uniformity in the threshold voltage, transconductance, and current-gain cutoff frequency of InAlAs/InGaAs/InP MODFETs has been achieved using a selective wet gate recess process. An etch rate ratio of 25 was achieved for InGaAs over InAlAs using a 1:1 citric acid:H/sub 2/O/sub 2/ solution. By using this solution for gate recessing, the authors have achieved a threshold voltage standard deviation of 15 mV and a transconductance standard deviation of 15 mS/mm for devices across a quarter of a 2-in-diameter wafer. The average threshold voltage, transconductance, and current-gain cutoff frequency of 1.0- mu m gate-length devices were -234 mV, 355 mS/mm, and 32 GHz, respectively.<>
Keywords :
III-V semiconductors; aluminium compounds; etching; gallium arsenide; high electron mobility transistors; indium compounds; solid-state microwave devices; -234 mV; 1 micron; 2 in; 32 GHz; HEMT; InAlAs-InGaAs-InP; citric acid; current-gain cutoff frequency; etch rate ratio; etch selectivity; selective wet gate recess; semiconductors; transconductance; uniform threshold voltage; wafer size; Cutoff frequency; Etching; HEMTs; Indium compounds; Indium gallium arsenide; Indium phosphide; MODFET circuits; MODFET integrated circuits; Threshold voltage; Transconductance;
Journal_Title :
Electron Device Letters, IEEE
