Analysis of Thermally Stimulated Current Spectroscopy in Semiinsulating GaAs. I. Initialization

Abstract

The operation of improved thermally stimulated current (TSC) spectroscopy is described and analysed. This method is suited for studying defects in semi-insulating (SI) GaAs at liquid-helium temperatures. This paper, the first in a series, presents an analysis of the first half process of TSC, that is, initialization, which consists of three stages: carrier generation, transport, and trapping. The initialization is analysed in terms of such parameters as electrode spacing, biasing voltage and polarity, excitation light energy and dose, and temperature. The analysis leads to new methods of determining the cross section of a deep level trap. From the photocurrent transient, the cross section was estimated for the dominant trap(s) as 5×10-15 cm2. Another method offers an estimation for nondominant trap levels.

Phosphorus-Vacancy-Related Deep Levels in Gainp Layers Grown by Molecular Beam Epitaxy

“…Therefore we conclude that the trap A is responsible for the hopping conduction. The absence of any change for trap A under different illumination time can not be explained by the carrier trapping process [16,17]. Analogous phenomina were also observed by Fang et al [ 18 ] and Desnica et al 1 9] in the semi-insulating GaAs ( T 3 in ref.…”

“…The capture cross section 0 n of trap B can be obtained by the method suggested by Tomozane et al [ 16 ]. This method is based on the dependence of peak height on illumination period.…”

Dielectric relaxation and defect analysis of Ta2O5thin films

“…However, when minority carriers are also involved, it is possible to have the sign of the effect reversed (C < 0), and thus have the apparent capacitance become negative [21,22]. The presence of such possible minority carriers (holes) in semiconductors were observed by Tomozane et al [23].…”

Identification of electron-irradiation defects in semi-insulating GaAs by normalized thermally stimulated current measurements

“…3 However, the TDH and DLTS techniques cannot be applied in semi-insulating ͑SI͒ GaAs, an important material that forms the basis of the GaAs microwave and integrated-circuit industries. A wellestablished method for looking at traps in SI materials is thermally stimulated current ͑TSC͒ spectroscopy; [5][6][7][8] however, TSC is not considered to be a quantitative technique because it involves carrier mobility, lifetime, and geometric factors, which are either unknown or poorly known. In this work we first show how to quantify a TSC spectrum, by normalizing with infrared photocurrent, and then apply this quantitative method ͑called NTSC͒ to study traps produced by electron irradiation in SI GaAs.…”