Numerical simulation of electron-beam-induced gate currents in a GaAs MESFET. I. Theory and model

Abstract

Electron-beam-induced current (EBIC) measurements can be used in order to investigate microscopic electrical properties of semiconductor materials and devices. However, for the estimation of material parameters and the unequivocal interpretation of EBIC micrographs, very often additional simulations are necessary. Up to now, these simulations have been carried out mostly using analytical models based on some restrictive simplifications. These models can only be used for simple specimen structures of high symmetry or for specimens that can be definitely separated into such simple structures. These models are not well suited to the simulation of electron beam currents in small devices such as MESFETs (metal-semiconductor field-effect transistors). Thus, we have used the more adaptable finite difference method for two-dimensional numerical simulations of electron-beam-induced gate currents in these devices. In this first part of the paper, the model and tools used are presented.

Numerical simulation of electron-beam-induced gate currents in a GaAs MESFET. II. Numerical and experimental results

“…In this section results obtained by the application of the simulation model presented in part I of this paper (Kaufmann and Balk 1995) are shown. Owing to the limited computer resources available, only two dimensional simulations have been carried out.…”

“…As the meaning of the simulation parameters is explained in part I of this paper (Kaufmann and Balk 1995), here only the values of parameters used for the subsequently shown simulation results are summarized in table I . Many parameters are known material parameters (Sze 1981).…”

“…The two-dimensional electron4ole-pair generation rate distribution is shown in figure 4 for primary electron energies of WPE = 4 and 20 keV. For the calculations of the generation rate distribution, the equations given in paxt I of this paper are used (Kaufmann and Balk 1995). At WPE = 4 keV the electron-hole pairs are generated mainly within the doped layer.…”