Numerical simulation of InN based HEMTs

Abstract

Invented in 1980, High Electron Mobility Transistors(HEMTs) are now widely used in high-frequency electronics. They are fabricated in different material systems and a possible new material for future devices is indium nitride (InN). InN HEMTs are considered very promising because of the good electron transport properties of the material predicted by Monte Carlo simulations. InN has a lower effective mass, higher mobility and higher peak drift velocity than GaN. Compared to (In)GaAs, the material also performs well. However, due to current problems with the InN material growth, the field of InN HEMTs is still at an early stage. This master’s thesis reports (one of) the first numerical simulations of InN HEMTs. It covers the implementation of a simulation model for such a device starting from a theoretical proposal in the literature. Its DC and AC output are analysed and compared to analytical calculations. Based on the agreement between both, it is concluded that the simulation model works correctly. The model was used to extract the potential performance of an InN HEMT. Using the best parameters and for a gate length of 100 nm, an extremely high ft and fmax of 400 and 430 GHz are obtained, respectively. However, it is also noted that these values depend a lot on the assumed high saturation velocity used in the model. At the end of the project, the simulation deck was also used to simulate some other InN HEMT structures.