Title :
Stress-related hydrogen degradation of 0.1-μm InP HEMTs and GaAs PHEMTs
Author :
Blanchard, Roxann R. ; del Alamo, J.A.
Author_Institution :
MIT, Cambridge, MA, USA
fDate :
6/1/2006 12:00:00 AM
Abstract :
Hydrogen degradation of III-V field-effect transistors (FETs) is a serious reliability concern. Previous work has shown that threshold-voltage shifts induced by H2 exposure in 1-μm-channel InP high-electron mobility transitors (HEMTs) can be attributed to compressive stress in the gate due to the formation of TiHx in Ti/Pt/Au gates. The compressive stress affects the device characteristics through the piezoelectric effect. This paper examined the H2 sensitivity of 0.1-μm strained-channel InP HEMTs and GaAs pseudomorphic HEMTs. After exposure to H2, the threshold voltage VT of both types of devices shifted positive. This positive shift in VT is predicted by a model for hydrogen-induced piezoelectric effect. In situ VT measurements reveal distinct time dependences of the VT shifts, which are also consistent with stress-related phenomena.
Keywords :
III-V semiconductors; field effect transistors; gallium arsenide; gold; indium compounds; piezoelectricity; platinum; power HEMT; titanium; 0.1 micron; GaAs; H2 sensitivity; HEMT; InP; PHEMT; Ti-Pt-Au; compressive stress; field effect transistor; piezoelectric effect; stress related phenomena; stress-related hydrogen degradation; Compressive stress; Degradation; FETs; Gallium arsenide; HEMTs; Hydrogen; Indium phosphide; MODFETs; PHEMTs; Piezoelectric effect; GaAs; InP; high-electron mobility transitor (HEMT); hydrogen; pseudomorphic high-electron mobility transitor (PHEMT); reliability;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2006.873882
