Title :
Inline sheet charge control during MBE production of AlGaAs/InGaAs pHEMTs using AlAs etch stopper for GaAs cap removal
Author :
Zhou, Guoliang ; Liu, Wayne ; Lin, M.-E.
Author_Institution :
Alpha Ind. Inc., Woburn, MA, USA
Abstract :
We report the investigation of using AlAs etch stopper for selective removal of GaAs cap in order to monitor sheet charge density during MBE production of AlGaAs/InGaAs pHEMTs. Etching selectivity/duration and Ohmic contact resistance were compared for AlAs layers with different thickness. PHEMT structures at different etching stages were characterized by Hall measurement, X-ray diffraction, and noncontact sheet resistance measurement. The stopping time for 5 to 25 Å AlAs films in ammonia hydroxide based etching solution was found to be within the range of 5 to 35 minutes. True sheet charge density confined within quantum well is routinely obtained without the interruptions of production for extra calibration growth
Keywords :
III-V semiconductors; aluminium compounds; contact resistance; etching; gallium arsenide; high electron mobility transistors; indium compounds; molecular beam epitaxial growth; semiconductor growth; 5 to 25 A; AlAs; AlAs etch stopper; AlGaAs-InGaAs; AlGaAs/InGaAs pHEMTs; GaAs; GaAs cap removal; Hall measurement; MBE production; Ohmic contact resistance; X-ray diffraction; etching duration; etching selectivity; inline sheet charge control; noncontact sheet resistance; sheet charge density; stopping time; Contact resistance; Electrical resistance measurement; Etching; Gallium arsenide; Indium gallium arsenide; Molecular beam epitaxial growth; Monitoring; Ohmic contacts; PHEMTs; Production;
Conference_Titel :
Compound Semiconductors, 2000 IEEE International Symposium on
Conference_Location :
Monterey, CA
Print_ISBN :
0-7803-6258-6
DOI :
10.1109/ISCS.2000.947125
