Ultraviolet Light-Based Current–Voltage Method for Simultaneous Extraction of Donor- and Acceptor-Like Interface Traps in $\beta$ -Ga 2 O 3 FETs

A novel technique is proposed for the simultaneous extraction of energy distribution of donor- and acceptor-like interface trap states [ ${D}_{\text {it}\_{}{D}}$ ( ${E}$ ) and ${D}_{\text {it}\_{}{A}}$ ( ${E}$ )] over a wide range of bandgap energy using deep UV light with sub-bandgap ( ${E}_{\text {ph}}={h}\nu ) photons less than the bandgap of the $\beta$ -gallium oxide ( $\beta$ -Ga 2 O 3 ) channel material in the $\beta$ -Ga 2 O 3 field-effect transistors. In the proposed technique, we characterized ${D}_{\text {it}\_{}{D}}$ ( ${E}$ ) and ${D}_{\text {it}\_{}{A}}$ ( ${E}$ ) separately based on the difference in the gate voltage ( ${V} _{\text {GS}}$ )-dependent ideality factors [ ${d} \Delta \eta$ ( ${V} _{\text {GS}}$ )/ $dV_{\text {GS}}$ ] for the photoresponsive carriers excited from ${D} _{\text {it}\_{}{D}}$ (E) and ${D} _{\text {it}\_{}{A}}$ ( ${E}$ ) under two different regions ( ${V} _{\text {ON}} and ${V} _{\text {FB}} ) in the subthreshold operation.