Characterization of deep centers in undoped semi-insulating GaAs substrates by normalized thermally stimulated current spectroscopy: Comparison of 100 and 150 mm wafers

Bulk GaAs grown under high oxygen potential shows an intermediate resistivity (ρ∼3×103 Ω cm at room temperature) with an electron activation energy E=0.42 eV. The relevant defect has been identified in literature as off-centered substitutional oxygen with three different charge states. Photoelectrical measurements on such GaAs material exhibit distinctly anomalous signals. Photoinduced current transient spectroscopy (PICTS) shows a signal with a negative sign, whereas thermally stimulated currents (TSCs) are clearly lower than the dark current. By means of a set of coupled differential equations, the carrier exchange between the defect levels and the conduction band is described. Solving these rate equations, the PICTS and TSC curves are modeled. In this way, it could be demonstrated that the anomalous PICTS and TSC signals are caused by the negative-U behavior of the off-center oxygen. This is in agreement with results of infrared spectroscopy.

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Characterization of deep centers in undoped semi-insulating GaAs substrates by normalized thermally stimulated current spectroscopy: Comparison of 100 and 150 mm wafers

Cited by 6 publications

References 11 publications

Role of contacts in characterization of deep traps in semi-insulating GaAs by thermally stimulated current spectroscopy

Role of contacts in characterization of deep traps in semi-insulating GaAs by thermally stimulated current spectroscopy

Oxygen in GaAs and its relation to the EL3 defect investigated by TSC and PICTS

Negative signals of photoinduced current transient and thermally stimulated current spectroscopy in GaAs due to negative-U properties of oxygen

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