Fabrication and Characterization of Lead Sulfide Thin Films by Atomic Layer Deposition

Abstract

We present a study of the deposition of lead sulfide (PbS) thin films by atomic layer deposition (ALD). PbS films were deposited from Pb(tmhd)2 and H2S precursors at precursor sublimation temperatures of 165-175 C. The film growth rate was 1.3-1.8 Aå/cycle, which is higher than previously published values. A linear growth rate characteristic of ALD was observed, with no chemical contamination. Film properties are studied using XPS, XRD, SEM and AFM measurements. AFM images show that the films are polycrystalline with grain size increasing with film thickness. Calculations have been performed using Density Functional Theory (DFT) to model the reaction mechanism.