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

The impact of La 2 O 3 /InGaAs MOS interfaces on the performance of InGaAs MOSFETs is systematically investigated. The low interface state density (D it ) of La 2 O 3 /InGaAs MOS interfaces is attributable to the formation of an intermixing layer between InGaAs and La 2 O 3 , which is rich in As 2 O 3 . The La 2 O 3 /InGaAs MOSFETs exhibit smaller subthreshold slope with the minimum value of 93 mV/dec than HfO 2 /InGaAs MOSFETs and smaller carrier trapping properties than Al 2 O 3 /InGaAs and HfO 2 /InGaAs MOSFETs. In the channel mobility analysis, it is found that La 2 O 3 /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 Al 2 O 3 /InGaAs MOSFETs.