Field-assisted emission in AlGaN/GaN heterostructure field-effect transistors using low-frequency noise technique

摘要

We utilized low-frequency noise measurements to probe electron capture and emission from the traps in AIGaN/GaN heterostructure field-effect transistors as a function of drain bias. The excess noise-spectra due to generation-recombination effect shifted higher in frequency with the elevated temperature from room temperature up to 446 K. These temperature dependent noise measurements were carried out for four different drain-bias values from 4 up to 16 V with 4 V increments. The shift of the excess-noise in frequency was also seen with increasing drain bias. The characteristic recharging times for the trapped electrons varied within the range of 26 μs - 32 ms for the highest and lowest values of the drain voltage and temperature used in the experiment, respectively. The activation energies of the traps corresponding to the four different voltage values were extracted using temperature dependence by Arrhenius analysis. The trap energy at zero drain-bias was obtained as 0.71 eV by the extrapolation technique. This result suggests that the LFN is a very sensitive diagnostic tool to characterize trap states.