The Precursor Adsorption Mechanism, Growth Characteristics and Electrical Properties of Plasma-Enhanced Atomic Layer Deposited Tungsten Films by Using Tungsten Chloride Precursors

Abstract

Atomic layer deposited tungsten (W) films has been widely used in widespread applications due to its good characteristics such as low resistivity, high thermal and chemical stability. WF6 is the most commonly used precursor for vapor deposition of W. Hydrofluoric acid (HF) byproduct, etching of substrate and diffusion of fluorine could degrade device performance. To overcome these issues fluorine-free tungsten precursors have recently received attention. In this work, we fundamentally investigated PE-ALD process of W by using tungsten chloride (WClx) precursor and argon and hydrogen plasma. Developed W process could deposit W films with low Cl impurity and low resistivity.