Achieving a low interfacial density of states in atomic layer deposited Al$_{2}$O$_{3 }$on In$_{0.53}$Ga$_{0.47}$As

Atomic-layer-deposited (ALD) Al$_{2}$O$_{3}$ dielectrics on In$_{0.53}$Ga$_{0.47}$As with short air exposure between oxide and semiconductor deposition has been demonstrated nearly ideal capacitance-voltage ($C-V)$ characteristics with negligible frequency dispersion at flat-band and accumulation. A relationship of surface potential versus gate voltage derived by the excellent quasi-static $C-V$ curve shows high efficiency of 63{\%} for Fermi-level movement near the mid-gap. A low mean interfacial density of states ($\overline D it) \quad \sim $ 2.5x10$^{11}$ cm$^{-2}$eV$^{-1}$ was determined using the charge pumping method, which was also employed to probe the depth profile of bulk trap density ($N_{bt})$ and the energy dependence of $D_{it}$ measured at 50kHz: a low $N_{bt} \quad \sim $ 7x10$^{19}$ cm$^{-3}$ and $D_{it}$ of 2-4x10$^{11}$ cm$^{-2}$eV$^{-1}$ in the lower half of the band-gap and a higher $D_{it}$ of $\sim $10$^{12}$ cm$^{-2}$eV$^{-1}$ in the upper half of the band-gap. The employment of charge pumping method has given a more accurate determination of $D_{it}$, which is usually overestimated using other commonly methods such as Terman, conductance, and high-low frequencies, due to the influence of weak inversion at room temperature.