Evaluation of Effective Device Parameters by Comparison of Measured and Simulated C-V Characteristics for Conventional and Pseudomorphic HEMTs

  • R. Deutschmann
  • C. Fischer
  • C. Sala
  • S. Selberherr
Conference paper


Measurements of the gate C-V characteristics of several conventional and pseudomorphic high electron mobility transistors (HEMT) on wafer and the comparison with simulations are presented. In order to study the influence of important technological parameters on the capacitance, the Schrödinger and Poisson equations were solved self-consistently in the structure, using the thickness of the doped layer d A ,the doping density N D and the built-in voltage V b as fit parameters. Measurement and simulation were found to be in good agreement and the fit parameters can be shown to be the effective device parameters. We demonstrate how to apply this technique for monitoring the spatial variation of d A ,N D and V b over the wafer, a result of particular importance for the development of the manufacturing process and for calibrating the design of the device.


High Electron Mobility Transistor Doping Density Dope Layer Gate Capacitance Charge Control 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [1]
    Ando, Y., Itoh, T.: Analysis of charge control in pseudomorphic twodimensional electron gas field-effect transistors. IEEE Trans. Electr. Dev., 35(12), 2295–2301, 1988CrossRefGoogle Scholar
  2. [2]
    Alamkan, J., Happy, H., Cordier, Y., Cappy, A.: Modelling of pseudomorphic AlGaAs/GaInAs/AIGaAs layers using selfconsistent approach. ETT, 1(4), 429–432, 1990Google Scholar
  3. [3]
    Schubert, E.F., Ploog, K.: Shallow and deep donors in direct-gap n-type Al x Ga 1-x As: Si grown by molecular-beam epitaxy. Phys. Rev. B, 30(12), 7021–7029, 1984CrossRefGoogle Scholar
  4. [4]
    Adachi, S.: GaAs, AlAs, and Al x Ga 1 - x As: Material parameters for use in research and device applications. J. Appl. Phys., 58(3), R1–R29, 1985CrossRefGoogle Scholar
  5. [5]
    Zhao, K., Kuhn, K.J.: Dislocation scattering in n-type modulation doped Al 0.3 Ga 0.7 As/In x.Ga 1-x.As/Al 0.3 Ga 0.7 As quantum wells. IEEE Trans. Electr. Dev., 38(12), 2582–2589, 1991CrossRefGoogle Scholar
  6. [6]
    Giugni, S., Tansley, T.L.: Comment on the compositional dependence of bandgap in AIGaAs and band-edge discontinuities in AIGaAs-GaAs heterojunctions. Semicond. Sci. Technol., 7, 1113–1116, 1992CrossRefGoogle Scholar
  7. [7]
    Chow, P.C.: Computer solutions to the Schrödinger equation. Am. J. Phys., 40, 730–734, 1972CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Wien 1993

Authors and Affiliations

  • R. Deutschmann
    • 1
  • C. Fischer
    • 2
  • C. Sala
    • 2
  • S. Selberherr
    • 2
  1. 1.Corporate Research and DevelopmentSiemens AGMünchenGermany
  2. 2.Institute for MicroelectronicsTU ViennaWienAustria

Personalised recommendations