Kinetics of Buffer-Related RON-Increase in GaN-on-Silicon MIS-HEMTs

• Published in: IEEE electron device letters Vol. 35; no. 10; pp. 1004 - 1006
• Main Authors: Bisi, Davide, Meneghini, Matteo, Marino, Fabio Alessio, Marcon, Denis, Stoffels, Steve, Van Hove, Marleen, Decoutere, Stefaan, Meneghesso, Gaudenzio, Zanoni, Enrico
• Format: Journal Article
• Language: English
• Published: IEEE 01-10-2014
• Subjects: Aluminum gallium nitride; Charge carrier processes; current collapse; dynamic RON; Gallium nitride; GaN; HEMT; Kinetic theory; Silicon; Stress; Substrates; temperature; trapping; temperature; current collapse; trapping; dynamic RON; GaN; HEMT
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2014.2344439

This letter reports an extensive analysis of the charge capture transients induced by OFF-state bias in double heterostructure AlGaN/GaN MIS- high electron mobility transistor grown on silicon substrate. The exposure to OFF-state bias induces a significant increase in the ON-resistance (R on ) of the devices. Thanks to time-resolved on-the-fly analysis of the trapping kinetics, we demonstrate the following relevant results: 1) R on -increase is temperature- and field-dependent, hence can significantly limit the dynamic performance of the devices at relatively high-voltage and high temperature (100 °C-140 °C) operative conditions; 2) the comparison between OFF-state and back-gating stress indicates that the major contribution to the R on -increase is due to the trapping of electrons in the buffer, and not at the surface; 3) the observed exponential kinetics suggests the involvement of point-defects, featuring thermally activated capture cross section; and 4) trapping-rate is correlated with buffer vertical leakage-current and is almost independent to gate-drain length.