Drain-Current Deep Level Transient Spectroscopy Study of Carrier Emission Process from InAs Quantum Dots in GaAs Narrow-Wire Field Effect Transistors

摘要

We studied the states working in the memory operation of GaAs narrow-wire field-effect transistors (FETs) with embedded InAs quantum dots (QDs). The GaAs narrow-wire FETs with a few InAs QDs above the channel were fabricated by selective-area metal organic vapor-phase epitaxy (SA-MOVPE). The drain current, measured by sweeping the gate voltage forward and backward, exhibited clear clockwise hysteresis due to the charging of electrons into the states induced by InAs QDs with a threshold voltage shift (Δ V_(th)) of 30 mV at 20 K. To better understand the mechanism of this memory operation, we studied the traps concerning the InAs QDs by drain-current deep-level transient spectroscopy (DLTS). Peaks representing three kinds of electron traps concerning InAs QDs were observed in the DLTS spectra. These peaks exhibited different dependences on the applied gate pulsed voltage during the DLTS measurement. In comparison with the temperature dependence of ΔV_(th), we found that our memory operation was attributed to one localized state introduced by InAs QDs.