BCl 3 /Ar Plasma-Induced Surface Damage in GaInP/InGaAs/GaInP Quantum-Well High-Electron-Mobility Transistors

• Published in: Japanese Journal of Applied Physics Vol. 37; no. 6B; p. L706
• Main Authors: Kuo, Chi-Wein, Su, Yan-Kuin, Kuan, Hrong
• Format: Journal Article
• Language: English
• Published: 01.06.1998
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.37.L706

BCl 3 plasma etching for gate recessing of GaInP/InGaAs/GaInP quantum-well high-electron-mobility transistors (QHEMTs) is found to be improved by the addition of an appropriate amount of Ar to the gas flow. The influence of the BCl 3 /Ar gas flow ratio on the etching selectivity of GaAs to GaInP and surface damage was studied. Surface damage was determined using Raman spectroscopy and drain-source current to gate-source voltage ( I ds - V gs ) measurements. For the BCl 3 /Ar flow ratio either lower or higher than 6/4, Raman spectra indicate that the plasma causes damage that will make the InP- and GaP-like longitudinal optical (LO) modes undergo redshift and their intensities to become smaller. The DC characteristics of QHEMT S 6:4 dry-etched with 6:4 BCl 3 /Ar were superior to those of the QHEMT S wet wet-etched, and QHEMT S 10:0 , dry-etched with pure BCl 3 . These results show that the use of the BCl 3 /Ar gas mixture has considerable potential for achieving high selectivity and low damage in GaInP/InGaAs/GaInP QHEMTs.