Comparative study of subthreshold characteristics of different antimonide-based and nitride-based dual material gate (DMG) HEMTs

As MOSFET technology reaching its limits, new devices like HEMTs (high electron mobility transistors) are gradually gaining more interests. HEMTs have high mobility due to reduce scattering for the spatially separated doped region. But as their dimensions reach the nano-scale region, different SCEs (short channel effects) and carrier transport inefficiency creep in. To solve these problems a new structure, DMG (dual material gate) HEMT has been proposed. In this paper we have shown comparison of subthreshold characteristics among different antimonide-based DMG HEMTs and between antimonide-based and nitride-based DMG HEMTs. We have found that as the band-offsets in the heterojunction become deeper, the effect of using DMG over SMG (single material gate) reduces in case of antimonide-based HEMTs. Our work also shows that DMG structure is more effective in reducing SCEs for antimonide-based HEMTs than nitride-based HEMTs, while nitride-based DMG HEMTs give more efficient carrier transport than its antimonide-based counterpart.