For Full-Text PDF, please login, if you are a member of IEICE,|
or go to Pay Per View on menu list, if you are a nonmember of IEICE.
Analysis of Passivation-Film-Induced Stress Effects on Electrical Properties in AlGaN/GaN HEMTs
Naoteru SHIGEKAWA Suehiro SUGITANI
IEICE TRANSACTIONS on Electronics
Publication Date: 2010/08/01
Online ISSN: 1745-1353
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Heterostructure Microelectronics with TWHM 2009)
Category: GaN-based Devices
GaN, HEMT, threshold voltage, piezoelectric effects, film stress,
Full Text: PDF(586.5KB)>>
Effects of stress in passivation films on the electrical properties of (0001) AlGaN/GaN HEMTs are numerically analysed in the framework of the edge force model with anisotropical characteristics in elastic properties of group-III nitrides explicitly considered. Practical compressive stresses in passivation films induce negative piezoelectric charges below the gates and bring forth a-few-volt shallower threshold voltages. In addition, the shift in the threshold voltage due to the compressive stress is proportional to LG-1.1-1.5 with gate length LG, which is comparable to the expectation based on the charge balance scheme. These result suggest that passivation films with designed stress might play a crucial role in realising AlGaN/GaN HEMTs with shallow or positive threshold voltages.