Reliable method for low field temperature dependent mobility extraction at Al2O3/GaN interface

Accurate split-CV mobility measurements require to overcome Bias Temperature Instabilities (BTI) which are a key issue in GaN-on-Si MOS-channel HEMTs (MOSc-HEMT). In this article, a rigorous methodology to extract the split-CV mobility as a function of the electron density and the temperature at Al
2
O
3
/GaN MOS interface is depicted. Drain current In(VG) and gate-to-channel capacitance CGc(VG) measurements are performed simultaneously under fast gate voltage V
G
ramp to prevent BTI. The voltage ramp enables fast C
GC
(V
G
) measurements and allows to bypass the frequency effect which can be observed when using small signal C
GC
(V
G
) measurements. Thus, this technique paves the way to a reliable determination of intrinsic electron transport properties of GaN transistors.