Comparative investigation of MBE and MOCVD PMHEMT structures for high frequency applications

This work presents a comparison of DC, RF and power characteristics at high frequency as well as a comparison of the uniformity of these parameters ac ross each wafer in pseudomorphic high electron mobility transistor structur es grown by MBE and MOCVD. In either case, both single and double heterostr uctures grown on 3" S. I. GaAs substrates were investigated. The comparison revealed that uniformity characteristics are similar, independent of the e pitaxial method used or of the type of heterostructure grown, and that devi ce uniformity mapping does not correlate to material uniformity mapping. In terms of power characteristics, double heterostructures exhibited better p erformance than single heterostructures for both epitaxial methods. (C) 199 9 Elsevier Science S.A. All rights reserved.