Direct Monitoring of the Hot-Carrier Accumulated Charge in GaN HEMT and PHEMT Devices

A Stopel1, A. Khramtsov1, O.Katz1, S. Solodky2, TG. Baksht2, Y. Knafo1, M. Leibovitch2 and Yoram Shapira1

1Department of Electrical Engineering - Physical Electronics, Tel-Aviv University, Ramat-Aviv 69978, Israel

2Gal-El (MMIC), P.O. Box 330, Ashdod 77102, Israel  
Email: shapira@eng.tau.ac.il +972-3-640-9452

A contactless methodology of directly monitoring walkout phenomena in HEMT devices has been demonstrated for PHEMT and GaN HEMT devices.  No walkout phenomena have been observed in GaN HEMT, while evolution of the surface photo voltage spectra (SPS) indicates accumulation of the positive electrical charge the buffer and surface layer of device, after RF power stress.  In PHEMT, walkout phenomena are due to the accumulation of the charge at surface traps, which have been introduced during manufacturing process.  The SPS make it easy to monitor this charge accumulation during RF power stress.

                                                14.19 pdf                 Return to TOC