Study of the charge transport mechanism in pulsed laser deposited AlN:Cr films

Abstract

AlN thin films doped with Cr (AlN:Cr) were prepared on p-Si(100) substrates by pulsed laser deposition. Al-AlN:Cr-Si MIS structures were formed and their current-voltage and 1 MHz admittance characteristics were measured and analyzed. The current through the MIS structure is proportional to the square of the applied voltage, which is evidence that the current is limited by space charge at traps in the AlN:Cr films. These traps are responsible also for the observed negative differential resistance and hysteresis of the current-voltage characteristics. The C-V and G-V characteristics measured at 1 MHz and the impedance measurements in 500 Hz-500 kHz frequency range without applying bias voltage are also influenced by the traps in the AlN:Cr films. © 2010 IOP Publishing Ltd.