Scalability of the drain-current drive of AlGaN/GaN HFETs with gate-length

• Studied role of velocity overshoot on scaling of drain current of AlGaN/GaN HFET.
• Provided rigorous matching to experimental results for the models.
• Evaluated drain current scaling without considering the velocity overshoot.
• Evaluated impact of improvement in Ohmic contact quality on scalability signatures.

The scaling-trend of the current-drive of AlGaN/GaN Heterostructure Field Effect Transistors (HFETs) with gate-length is studied with the application of a realistic steady-state drift transport characteristics and an approximate purely-saturating drift transport characteristics. Findings show that due to an overwhelming presence of a region of negative differential mobility in the transport characteristics of GaN, a scaling-trend different from the one observed in mainstream silicon MOSFETs should be expected for AlGaN/GaN HFETs. The role of improvement in Ohmic contact technology on this scaling trend is also investigated.