Performance and Reliability of Nanosheet Oxide Semiconductor FETs with ALD-Grown InGaO for 3D Integration (Invited)

We developed ALD InGaOx (IGO) and InSnOx deposition process for channel and electrode, respectively. We systematically investigated the relationship among mobility, electrostatics, and reliability by studying composition and thickness dependence, and confirmed clear trade-off in IGO FETs. To break this trade-off, we designed and fabricated double-gate nanosheet IGO FETs demonstrating normally-off operation, high mobility and high reliability, simultaneously. This work provides a practical device design guide for developing ALD-based oxide semiconductor FET for 3D integrated devices.