TECHNICAL FIELD

Embodiments of the present disclosure generally relate to methods for depositing rhenium-containing thin films. In particular, embodiments of the disclosure are directed to methods of depositing rhenium-containing thin films by atomic layer deposition in the absence of a halide.

BACKGROUND

Deposition of thin films on a substrate surface is an important process in a variety of industries including semiconductor processing, diffusion barrier coatings, and dielectrics for magnetic read/write heads. In the semiconductor industry, in particular, miniaturization requires atomic level control of thin film deposition to produce conformal coatings on high aspect structures.

One method for deposition of thin films is atomic layer deposition (ALD). Most ALD processes are based on binary reaction sequences, where each of the two surface reactions occurs sequentially. Because the surface reactions are sequential, the two gas phase reactants are not in contact, and possible gas phase reactions that may form and deposit particles are limited.

As microelectronic device sizes become smaller, challenges exist with current metal films used for contacts, barrier layers, etc. New metals and metal films are needed for a variety of applications in microelectronic devices. Rhenium has not been previously used in microelectronic applications. Accordingly, there is a need in the art for new methods of depositing rhenium-containing films for microelectronic devices.

SUMMARY

One or more embodiments of the disclosure are directed to methods of depositing a film. A substrate is exposed to a rhenium precursor to deposit a film on the substrate. The processing chamber is purged of the rhenium precursor and the substrate is exposed to a reducing agent to react with the film to form one or more of a rhenium metal film, a rhenium metal nitride film, a rhenium oxide film, or a rhenium carbide film on the substrate. The processing chamber is then purged of the reducing agent.

Additional embodiments of the disclosure are directed to methods of depositing a film. A metal film is selectively formed by a process cycle comprising sequential exposure of a substrate to a rhenium precursor, purge gas, a reducing agent, and purge gas. The process cycle is repeated to selectively form a rhenium film on the substrate, wherein the rhenium film is substantially free of halide.

Further embodiments of the disclosure are directed to methods of depositing a film comprising selectively forming a rhenium-containing film in a process cycle comprising sequential exposure of a substrate to a rhenium precursor, purge gas, reducing agent, and purge gas, wherein the rhenium-containing film is substantially free of halide.

