Band-structure of ultra-thin InGaAs channels: Impact of biaxial strain and thickness scaling

The band-structure of ultra-thin InGaAs layers is calculated using a nearest neighbor sp3d5s* tight binding approach to assess the impact of compressive and tensile biaxial strain on effective in-plane masses, non-parabolicity factor α, and conduction band minimum (CBM) shift down to channel thicknesses of 4 nm. The reported results show that the effective mass increases with body thickness decrease, whereas it decreases with the strain increase from compressive to tensile. Furthermore, the difference between the position of pinned Fermi level and CBM increases with strain. The impact of band-structure effects on electron transport is demonstrated for the InGaAs-OI structure. The extracted band-structure parameters provide electron mobility results consistent with experiments. Our calculations make it possible to assess the electron mobility in a wide range of both compressive and tensile strain values and body thicknesses from 15 nm down to 4 nm.