Impact of La2O3/InGaAs MOS Interfaces on the Performance of InGaAs MOSFETs

Abstract

The impact of La2O3/InGaAs MOS interfaces on the performance of InGaAs MOSFETs is systematically investigated. The low interface state density ( ${D}_{{\text {it}}}$ ) of La2O3/InGaAs MOS interfaces is attributable to the formation of an intermixing layer between InGaAs and La2O3, which is rich in As2O3. The La2O3/InGaAs MOSFETs exhibit smaller subthreshold slope with the minimum value of 93 mV/dec than HfO2/InGaAs MOSFETs and smaller carrier trapping properties than Al2O3/InGaAs and HfO2/InGaAs MOSFETs. In the channel mobility analysis, it is found that La2O3/InGaAs MOSFETs have higher Coulomb scattering probability due to the higher oxide fixed charge density and resulting degradation of the channel mobility, while have smaller surface roughness than Al2O3/InGaAs MOSFETs.