Contacts with interface fermi level tuning layers

Abstract

Transition metal dichalcogenide (TMD) monolayers are positioned between a contact metal and a semiconductor to pin the Fermi level at the metal-semiconductor interface. The pinned Fermi level can provide for a lower Schottky barrier height between the contact metal and semiconductor than if no TMD were present at the contact metal-semiconductor interface. The height of the Schottky barrier can be tuned through the selection of the transition metal dichalcogenide used for the monolayer. Transition metal dichalcogenides have the chemical formula MX, where M is a transition metal and X=sulfur, selenium, or tellurium. The transition metal dichalcogenides used for metal contact-semiconductor interfaces can have M=titanium, platinum, molybdenum, tungsten, erbium, rhodium, or lanthanum. A lower Schottky barrier height can reduce contact resistance, which can improve transistor performance as the parasitic resistance of source/drain channels approach that of transistor channel as transistor geometries continued to scale.