Electron mobility-lifetime and resistivity mapping of GaAs:Cr wafers
- 1 February 2017
- journal article
- Published by IOP Publishing in Journal of Instrumentation
- Vol. 12 (2), C02016
- https://doi.org/10.1088/1748-0221/12/02/c02016
Abstract
Previous works onchromium compensated gallium arsenide (GaAs:Cr) have shown high efficiency, good spatial and energy resolution, which is obviously connected with the high quality of material itself. The purpose of this research was to aggravate the diffusion process by increasing the annealing temperature and to observe whether there will be any degradation of material characteristics. The investigation of three 3-inch GaAs:Cr wafers with different annealing temperature of chromium was carried out. Resistivity and mobility-lifetime measurements were made using pad sensors made of these wafers. The I-V curves were built to estimate the resistivity across the wafer. Furthermore charge collection efficiency (CCE) measurements were carried out in order to estimate the μeτ e product of GaAs:Cr. The resistivity mapping has showed a variation of resistivity across the wafer in the range from 1.25 × 109 to 5.5 × 108 Ohm cm. Although the third wafer showed quite good uniformity, the resistance didn't reached values higher than 3.5 × 108 Ohm cm. In spite of harsh diffusion conditions all the materials showed quite good CCE (about 90%) and μ eτe more than 5 × 10−5 cm2/V. Also a strong dependency between the resistivity and mobility-lifetime product was found only for one wafer. So the uniformity of μeτ e product across the wafer can be stated independently of resistivity. More detailed information and discussion of experimental results is presented in the article.Keywords
This publication has 11 references indexed in Scilit:
- Chromium compensated gallium arsenide detectors for X-ray and γ-ray spectroscopic imagingNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2014
- Characterization of photon counting pixel detectors based on semi-insulating GaAs sensor materialJournal of Physics: Conference Series, 2013
- X-ray and γ-ray detectors based on GaAs epitaxial structuresNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2004
- GaAs detectors for medical imagingNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2003
- GaAs as a material for particle detectorsNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2002
- Epitaxial structures based on compensated GaAs for γ- and X-ray detectorsNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2001
- Modeling of processes of charge division and collection in GaAs detectors taking into account trapping effectsNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2001
- GaAs X-ray coordinate detectorsNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2001
- GaAs structures with deep centres for ionizing radiation detectionNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1997
- Radiation resistance of GaAs structures based on pi - nu junctionsJournal of Physics D: Applied Physics, 1995