A Nanosheet Oxide Semiconductor FET Using ALD InGaOx Channel and InSnOx Electrode with Normally-off Operation, High Mobility and Reliability for 3D Integrated Devices

We have developed ALD InGaOx (IGO) and InSnOx deposition process for channel and electrode, systematically investigated the trade-off among mobility, electrostatics, and reliability in IGO FETs, designed and fabricated multi-gate nanosheet IGO FETs demonstrating normally-off operation, high mobility and reliability, simultaneously, for the first time. This work provides a practical device design guide for developing ALD-based oxide semiconductor FET for 3D integrated devices.