Title :
Improved reliability self-aligned C/X-band monolithic power HBT amplifiers fabricated with a low-stress process
Author :
Henderson, T.S. ; Kim, T.S.
Author_Institution :
Corp. Res. & Dev., Texas Instrum. Inc., Dallas, TX, USA
Abstract :
We report extensive reliability testing and analysis on GaAs single-finger C/X-band HBTs fabricated for monolithic amplifiers with a low-stress process, The HBTs are self-aligned to maximize RF power performance, with ledge passivation and a low stress epitaxial base and dielectric overcoat to improve reliability. Performed from T/sub jo/=185-340/spl deg/C and J/sub co/=25-50 kA/cm/sup 2/. The temperature and current dependence of the various observed failure modes and mechanisms are described. Long-term (>3000 hour), low temperature (<250/spl deg/C), high current stress tests are found to be accurate indicators of how HBTs degrade under nominal operating conditions. Shorter, high temperature tests may lead to excessively optimistic predictions of activation energy and median time to failure.
Keywords :
III-V semiconductors; MMIC power amplifiers; bipolar MMIC; failure analysis; gallium arsenide; heterojunction bipolar transistors; integrated circuit reliability; integrated circuit testing; passivation; 185 to 340 degC; C-band; GaAs; RF power performance; X-band; activation energy; dielectric overcoat; failure modes; high current stress tests; ledge passivation; low-stress process; median time to failure; power HBT amplifiers; reliability; self-aligned circuits; Automatic testing; Dielectrics; Gallium arsenide; Heterojunction bipolar transistors; Passivation; Performance analysis; Radio frequency; Radiofrequency amplifiers; Stress; Temperature;
Conference_Titel :
Gallium Arsenide Integrated Circuit (GaAs IC) Symposium, 1996. Technical Digest 1996., 18th Annual
Conference_Location :
Orlando, FL, USA
Print_ISBN :
0-7803-3504-X
DOI :
10.1109/GAAS.1996.567629
