Improved Thermally Stimulated Current Spectroscopy to Characterize Levels in Semi-Insulating GaAs

Abstract

Deep levels in semi-insulating GaAs were observed at low temperatures by means of improved thermally stimulated current (TSC) spectroscopy. The improvement was done by thinning the specimen and adding a guard ring electrode. The ionization energy of the levels was limited to below 0.7 eV. The concentration of 10 13 cm -3 was easily measured with an electrode area of 5 mm 2 . Spectra by electron traps and hole traps were separated by changing the bias polarity.