Self-aligned InGaAs FinFETs with 5-nm fin-width and 5-nm gate-contact separation

Abstract

We demonstrate self-aligned InGaAs FinFETs with fin widths down to 5 nm fabricated through a CMOS compatible front-end process. Precision dry etching of the recess cap results in metal contacts that are about 5 nm away from the intrinsic portion of the fin. The new process has allowed us to fabricate devices with undoped fins and compare them with delta-doped fins. We find that in highly scaled transistors, undoped fin devices show better OFF-state and a tighter VT distribution but similar ON-state characteristics, as compared with δ-doped-fin transistors. 2D Poisson-Schrodinger simulations reveal undoped fins making more effective use of the fin height.