Walkout in PHEMTs: Origin and Relation to Device Structure
1 Department of Electrical Engineering – Physical Electronics, Tel-Aviv University, Ramat-Aviv 69978, Israel
2 Gal-El (MMIC), P.O. Box 330, Ashdod 77102, Israel
E-mail: email@example.com; Fax: 972-3-6423508 Phone: 972-3-6408015,
Keywords : HEMT, walkout, device design, impact ionization, empirical modeling
Parameter walkout of more than 250 power Al0.24Ga0.76As/In0.25Ga0.75As/GaAs double-recessed PHEMTs with different layout geometry and epitaxial structure has been experimentally measured and simulated. The relation between DC, small-signal and large-signal behavior has been recognized. The essential parameters of walkout were defined; their geometry and structural dependence have been derived. Possible methods of walkout control are discussed.