Delta-doped HfO2/In0.53Ga0.47As inversion layers: Density-of-states bottleneck and electron mobility

In_0.53Ga_0.47As has become a material of interest for the continuation of Moore´s Law because of its high bulk electron mobility compared to Si. One problem associated with small effective-mass semiconductors such as InGaAs is the density-of-states bottleneck, or the loss of gate-capacitance due to the low density-of-states in the conduction band. The delta-doping profile is one way to reduce the effective gate oxide thickness by confining the band-bending (and thus electron density) to a few-nanometer region under the gate. This work seeks to theoretically understand the effect of a delta-doping profile on the capacitance-voltage characteristic and electron mobility of high-k/In_0.53Ga_0.47As inversion layers.