Characterization of multilayer gaas/algaas transistor structures by variable angle spectroscopic ellipsometry

Kenneth G. Merkel, John A. Woollam

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Variable angle of incidence spectroscopic ellipsometry (VASE) has been implemented as a means of determining layer thickness, alloy composition, and growth quality of GaAs/AlGaAs samples composed of relatively thick layers as well as superlattices. The structures studied in this work contained GaAs/AlGaAs multilayers with a superlattice 舠barrier舡 and were grown for later formation of modulation-doped field effect transistors (MODFETs). Sample modeling was performed by treating the superlattice as a bulk AlGaAs layer of unknown composition. Extremely good data fits were realized when five layer thicknesses and two alloy ratios were allowed to vary in a regression analysis. Room temperature excitonic effects associated with the e-hh(1), e-lh(1) and e-hh(2) transitions were observed in the VASE data.

Original languageEnglish (US)
Pages (from-to)1118-1123
Number of pages6
JournalJapanese Journal of Applied Physics
Issue number6 R
StatePublished - Jun 1989
Externally publishedYes


  • Ellipsometry
  • Gaas, algaas multilayer transistors
  • Layer thicknesses
  • Spectroscopic
  • Variable angle

ASJC Scopus subject areas

  • General Engineering
  • General Physics and Astronomy


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