Resistive Approach for Extraction of Bias-Dependent Parasitic Resistance, Mobility and Virtual Gate Length in GaN HEMT

In this work, we introduce a resistive approach to extract various device performance parameters such as contact resistance, mobility and effective gate length. Without passivation of the un-gated region, HEMT device leads to forming of an extra gate length either side of gate called virtual gate length (δ
LG
). Carrier mobility (µ
C
) of 2DEG and δ
LG
also depends upon V
GS
(gate bias). The depleted channel also reduces the device current causing a significant increase in source/drain resistance (R
S
/R
D
).