Systems and methods of forming tantalum silicide layers

Abstract

A method of forming (and apparatus for forming) tantalum silicide layers (including tantalum silicon nitride layers), which are typically useful as diffusion barrier layers, on a substrate by using a vapor deposition process with a tantalum halide precursor compound, a silicon precursor compound, and an optional nitrogen precursor compound.

Description

[0001] This is a divisional of U.S. patent application Ser. No. 10 / 229,813, filed Aug. 28, 2002, (pending), which is incorporated herein by reference.FIELD OF THE INVENTION [0002] This invention relates to methods of forming tantalum layers containing silicon (suicide layers) and optionally nitrogen (silicon-nitride layers) on substrates using a vapor deposition process. The formed tantalum-containing layers are particularly useful as diffusion barriers for polysilicon substrates to reduce diffusion of oxygen, copper, or silicon. BACKGROUND OF THE INVENTION [0003] In very-large-scale integration (VLSI) technology, tantalum suicide has been proposed to be useful in a variety of applications. These include: policide gate metallization (i.e., the use of tantalum silicide in combination with a doped polycrystalline silicon (poly-Si) underlayer as a low resistive gate metallization layer); silicide gate (i.e., the use of tantalum silicide as a directly deposited layer on a gate oxide to ...

AI Technical Summary

Benefits of technology

The method achieves highly conformal and uniform tantalum silicide and tantalum silicon nitride layers, effectively preventing diffusion of oxygen, copper, and silicon, enhancing the reliability and performance of semiconductor devices by minimizing defects and ensuring sufficient barrier thickness.

Problems solved by technology

However, when PVD methods are used, the stoichiometric composition of the formed metal silicon nitride barrier layers such as Ta—Si—N can be non-uniform across the substrate surface due to different sputter yields of Ta, Si, and N. Due to the resulting poor layer conformality, defects such as pinholes often occur in such layers creating pathways to diffusion.

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