C-V analysis of the Schottky barrier in undoped semi-insulating GaAs

Abstract

An analysis is presented of the influence of the quasi-neutral base and the back contact on the measured C-V dependence of the Schottky barrier in undoped semi-insulating (USI) GaAs. It is shown that under specific experimental conditions, which include temperature, test signal frequency and sample geometry, routine C-V analysis can be applied to calculate the effective charge in the Schottky barrier, which is controlled by the concentration of fully ionized ELEo/+, native donor-like states, if the capacitance is measured at a sufficiently low test signal frequency. Results of the low-frequency C-V analysis of the Schottky barrier in bulk us GaAs supplied by four different manufacturers are presented. The existence of a depletion regionin USI GaAs under the metal or injecting contact is demonstrated in a convincing way and the concentration of the effective charge in the barrier is determined.

Saturated electric field effect at semi-insulating GaAs-metal junctions studied with a low energy positron beam

“…Recently metal/semi-insulating ͑SI͒-GaAs constants have attracted both scientific and technological interest. [1][2][3][4][5] Some of the SI-GaAs Schottky contact devices, such as radiation detectors, require operation under large reverse bias conditions and thus the distribution of the electric field at such contacts has become an important area of study. [3][4][5] The positron, being a positive carrier of electric charge that possesses a simpler band structure and a relatively larger effective mass than its hole counterpart, 6 can be usefully employed as an effective electric field probe within a semiconductor since the drift motion of the particle can be detected in a number of ways.…”

GaAs Pixel-Detector Technology for X-ray Medical Imaging: A Review

“…Methods for characterization of bulk materials include measurement of conductivity and the Hall mobility, glow-discharge mass spectroscopy, and current-voltage and capacitance-voltage techniques [25,29]. Sensing capabilities are evaluated with gamma-ray sources using 57 Co or 241 Am.…”