Apparatus for fabricating a conformal thin film on a substrate

Abstract

An apparatus for fabricating a conformal thin film on a substrate are disclosed. The apparatus includes a top shield having a top surface and a bottom surface and a bottom shield having an aperture formed therein and a thickness. The bottom shield is coupled to the bottom surface of the top shield such that the top shield covers the aperture. The apparatus further includes a substrate holder that may hold a substrate. The substrate holder is in contact with the bottom shield such that a reaction chamber is formed having a volume defined by the aperture and the thickness of the bottom shield.

Description

RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. b 10 / 706,637, filed Nov. 12, 2003 and entitled “METHOD AND APPARATUS FOR FABRICATING A CONFORMAL THIN FILM ON A SUBSTRATE” now U.S. Pat. No. ______.TECHNICAL FIELD OF THE INVENTION [0002] The present invention generally relates to film deposition, and more particularly to an apparatus for fabricating a conformal thin film on a substrate. BACKGROUND OF THE INVENTION [0003] Atomic layer deposition (ALD), also known as sequential pulsed chemical vapor deposition (SP-CVD), atomic layer epitaxy (ALE) and pulsed nucleation layer (PNL) deposition, has gained acceptance as a technique for depositing thin and continuous layers of metals and dielectrics with high conformality. In an ALD process, a substrate is alternately dosed with a precursor and one or more reactant gases so that reactions are limited to the surface of a substrate. Uniform adsorption of precursors on the wafer surface during ...

AI Technical Summary

Benefits of technology

The solution increases the throughput of the ALD system by ensuring uniform precursor distribution and reducing the frequency of cleaning processes, leading to a more efficient and uniform film deposition on substrates.

Problems solved by technology

Although ALD techniques support deposition of conformal thin layers, a drawback of the technique is the low average deposition rate, which is related to the need to repeat several cycles having finite durations.

For example, the repeated cycle of precursor and reactant adsorption and the intervening chamber purges is time consuming, which results in reduced throughput relative to conventional deposition techniques.

One of the effects of increasing purge gas flow speed is the occurrence of turbulence in the gas injector.

The decrease in gas flow through openings near the turbulent zone when compared to the gas flow through openings located away from the turbulent zone may create an uneven distribution of precursor during a doping pulse, which ultimately forms a non-uniform film on a substrate.

Additionally, recirculation of gas in the expansion zone caused by the turbulence leads to inefficient purging of the precursors from the expansion zone, which may cause gas phase reactions that form a powder in the expansion zone.

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