Impact of La2O3/InGaAs MOS interface on InGaAs MOSFET performance and its application to InGaAs negative capacitance FET

The impact of La2O3/InGaAs MOS interfaces on the performance of InGaAs MOSFETs and the physical origins are systematically investigated. It is found that La2O3/ InGaAs MOSFETs exhibit lower S. S. and lower carrier trapping properties, while have lower mobility than Al2O3/ InGaAs MOSFETs because of higher fixed oxide charge density. Also, it is experimentally found for the first time that ALD La2O3 films with thermal budget lower than 300°C have ferroelectricity in W/La2O3/InGaAs MOS and W/La2O3/W MIM structures. The steep slope characteristics due to the negative capacitance (NC) effect have been demonstrated for the first time in W/La2O3(15nm)/InGaAs MOSFETs.