Narrowing of band gap at source/drain contact scheme of nanoscale InAs–nMOS

Abstract

A multi-scale simulation study of Ni/InAs nano-scale contact aimed for the sub-14 nm technology is carried out to understand material and transport properties at a metal-semiconductor interface. The deposited Ni metal contact on an 11 nm thick InAs channel forms an 8.5 nm thick InAs leaving a 2.5 nm thick InAs channel on a p-type doped (1×10 16 cm-3) AlAs 0.47 Sb 0.53 buffer. The density functional theory (DFT) calculations reveal a band gap narrowing in the InAs at the metal-semiconductor interface. The one-dimensional (1D) self-consistent Poisson-Schrödinger transport simulations using real-space material parameters extracted from the DFT calculations at the metal-semiconductor interface, exhibiting band gap narrowing, give a specific sheet resistance of R sh = 90.9 Ω /sq /sq which is in a good agreement with an experimental value of 97 Ω /sq.