Title :
Reliability of InGaAs HEMTs on GaAs substrates
Author :
Christou, A. ; Hu, J.M. ; Anderson, W.T.
Author_Institution :
Maryland Univ., College Park, MD, USA
Abstract :
The authors report on the reliability results of an optimised doped channel heterojunction field effect transistor (DCHEMT) with an InGaAs channel delta-doped to 1.5*10/sup 12/ cm/sup -2/. They compare the reliability results with those obtained for a single channel HEMT (SHEMT). The transistors were fabricated with a T-gate process and with 0.5*150 mu m or 1.0*200 mu m, PdAu or TiPdAu gates. Pseudomorphic-based devices were found to have better turn-off characteristics, output conductance, and breakdown characteristics than InP-based devices or GaAlAs/GaAs HEMTs. The doped channel pseudomorphic HEMT median time before failure (MTBF) of 4*10/sup 4/ h at 110 degrees C is shown to be limited by dislocations at the InGaAs-GaAs interface and ohmic contact degradation.<>
Keywords :
III-V semiconductors; failure analysis; gallium arsenide; high electron mobility transistors; indium compounds; reliability; GaAs substrates; InGaAs-GaAs interface; MTBF; PdAu gate; T-gate process; TiPdAu gates; breakdown characteristics; delta-doped channel; dislocations; heterojunction field effect transistor; median time before failure; ohmic contact degradation; optimised doped channel; output conductance; pseudomorphic HEMT; reliability; turn-off characteristics; Degradation; Electric breakdown; FETs; Gallium arsenide; HEMTs; Heterojunctions; Indium gallium arsenide; MODFETs; Ohmic contacts; PHEMTs;
Conference_Titel :
Reliability Physics Symposium, 1991, 29th Annual Proceedings., International
Conference_Location :
Las Vegas, NV, USA
Print_ISBN :
0-87942-680-2
DOI :
10.1109/RELPHY.1991.146015
