Study of InGaAs-Based Modulation Doped Field Effect Transistor Structures Using Variable-Angle Spectroscopic Ellipsometry

Authors

• S. A. Alterovitz, National Aeronautics and Space Administration, Lewis Research Center, Cleveland, Ohio
• R. M. Sieg, Cleveland State University, Department of Electrical Engineering, Cleveland, Ohio
• H. D. Yao, University of Nebraska - Lincoln
• Paul G. Snyder, University of Nebraska-LincolnFollow
• John A. Woollam, University of Nebraska-LincolnFollow
• J. Pamulapati, University of Michigan, Department of Electrical Engineering and Computer Science, Ann Arbor, MI
• P. K. Bhattacharya, University of Michigan, Department of Electrical Engineering and Computer Science, Ann Arbor, MI
• P. A. P. A. Sekula-Moise, Spire Corporation, Bedford, MA

Document Type

Article

Date of this Version

1991

Comments

Published in Thin Solid Films, 206 (1991) 288-293. Copyright © 1991 Elsevier Sequoia, Lausanne. Used by permission.

Abstract

Variable-angle spectroscopic ellipsometry was used to estimate the thicknesses of all layers within the optical penetration depth of InCaAs-based modulation doped field effect transistor structures. Strained and unstrained InGaAs channels were made by molecular beam epitaxy (MBE) on InP substrates and by metal-organic chemical vapor deposition on GaAs substrates. In most cases. ellipsometrically determined thicknesses were within 10% of the growth-calibration results. The MBE-made InCaAs strained layers showed large strain effects, indicating a probable shift in the critical points of their dielectric function toward the InP lattice-matched concentration.