IEDM 2023
Conference paper

High Performance Nanosheet Technology Optimized for 77 K


We provided process/integration solutions for high performance Nanosheet technology at 77 K and evaluated its performance benefits. This is the first demonstration of CMOS Nanosheet integration of dual work function metals (WFMs) and dual dipoles with functional ring oscillator (RO) and SRAM at 300 K and 77 K. WFM engineering plus dual dipole engineering provides target threshold voltage (Vt) solution for Nanosheet technology at 77 K. Nanosheet with low VDD (0.3 - 0.4 V) at 77 K provides comparable performance to that at 300K with VDD=0.75V, but at much lower power. Nanosheet at 77 K also offers more than 100% performance gain than at 300 K with same VDD=0.75V. Junction/contact optimization and multiple Vts (multi-Vt) feasibility were demonstrated. TCAD was also developed to evaluate device performance and variations at 77 K.