InAlAs/InGaAs/InP MODFET's with uniform threshold voltage obtained by selective wet gate recess

• Published in: IEEE electron device letters Vol. 13; no. 10; pp. 525 - 527
• Main Authors: Tong, M., Nummila, K., Ketterson, A., Adesida, I., Caneau, C., Bhat, R.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.10.1992; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Cutoff frequency; Electronics; Etching; Exact sciences and technology; HEMTs; Indium compounds; Indium gallium arsenide; Indium phosphide; MODFET circuits; MODFET integrated circuits; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Threshold voltage; Transconductance; Transistors; Cut off frequency; Voltage threshold; High electron mobility transistor; Microelectronic fabrication; Gallium Indium Arsenides Mixed; Indium Phosphides; Junction field effect transistor; Aluminium Indium Arsenides Mixed; Selective etching; Current gain; Transconductance
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/55.192822

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.< >