ALD TiN Surface Defect Reduction for 12nm and Beyond Technologies

Abstract

Atomic layer deposition (ALD) TiN metal films are used in semiconductor manufacturing for various purposes, such as work function metal, metal cap, and barrier films. ALD TiN chamber and process generate different types of particle defects having different morphologies and compositions. One of the main types of defect was found to be TiN surface particle from tetrakis-dimethylamino titanium (TDMAT). This work presents a solution to reduce the surface defects that are generated from the condensation of TDMAT. In this work, heated gas lines for He carrier gas and other process gases, such as Ar and N2, were used to reduce surface defects from ALD TiN. Two methods for heating gas lines were evaluated. In one method, gas lines with in-build heater were used and, in another method, heating jackets were used to heat the gas lines. A detailed material characterization of ALD TiN film using SIMS, XRD, and XPS was carried out to understand the influence of heated process gases on ALD TiN film properties. A significant surface defects reduction of more than 30% was achieved using the heated gas lines of process gases.