Photo-Induced Current Transient Spectroscopy in High-Resistivity Bulk Material. III. Scanning-PICTS System for Imaging Spatial Distributions of Deep-Traps in Semi-Insulating GaAs Wafer

Abstract

Atomic force microscope (AFM) oxidation was applied for the direct oxidation of a thin InAs layer in order to fabricate a single-electron transistor (SET) from an InAs/AlGaSb heterostructure. By employing the oxidized InAs as an insulator to form an in-plane-gate structure, SET structures were fabricated. For the improvement of the electrical properties of the InAs oxide as an insulator, a thinner InAs channel layer (10 nm) was introduced. This layer enables the AFM oxidation process at relatively low tip voltages with reduced tip wear. An improved breakdown voltage of as high as 1 V with a negligible leakage current of less than 1 nA was obtained. By using the 10-nm-thick InAs channel layer, SETs with a one-or two-isolated island structure were fabricated. The device characteristics measured at 4.2 K show SET characteristics confirming the successful formation of the gate insulator. While the SET with one island showed reproducible Coulomb oscillations, the other showed unstable oscillatory behavior due to the sensitivity of the structure to background charges. The improved SET characteristics evidenced by the clear Coulomb diamond structure indicate that the introduction of the thinner InAs channel layer is critical.

Local Mapping of Generation and Recombination Lifetime in BiFeO3 Single Crystals by Scanning Probe Photoinduced Transient Spectroscopy

“…Photoconductance decay and photoinduced transient spectroscopy are methods developed at the eve of the semiconductor physics and technology to characterize the electronic properties of semiconductors, especially lifetime and trap states in the band gap. , PITS uses light pulses to excite ehp and to study the decay of photoelectric currents after the cessation of the optical excitation. It gives information on the recombination lifetime and a temperature-dependent study allows to determine trapping levels in the band gap even with a certain spatial resolution limited by the excitation beam. − …”

Defect topography on GaAs wafers by microwave‐detected photo‐induced current transient spectroscopy

“…We assume that γ in our experiments is still much lower in the case of MD-PICTS compared to conventional PICTS. Therefore defect 5 is only recognisable because the maximum possible heights of defect 4 and defect 6 are not yet achieved. The MD-BB-PICTS spectra only detects defects 2 and 3.…”

“…There are also PICTS measurements by microwave absorption in the literature [4,5], however, without spatial resolution. On the other hand, there are spatially resolved PICTS measurements with destructive contacts, but with a spatial resolution of only 1 mm [6].…”

Optical Transient Current Spectroscopy of Deep Levels in Semi‐Insulating Indium Phosphide

“…As well as making the process excessively time consuming, the large temperature sweeps can induce degradation of the sample. Abele et al (9) noted changes in dark current as an order of magnitude from sweep to sweep.Digital OTCS, in which the whole transient is digitized and stored, (10,12,9) still allows the classical method of …”

“…Digital OTCS, in which the whole transient is digitized and stored, (10,12,9) still allows the classical method of * Electrochemical Society Student Member. ** Electrochemical Society Active Member.…”