Method and apparatus for providing and integrating a general metal delivery source (GMDS) with atomic layer deposition (ALD)

Abstract

A General Metal Delivery Source (GMDS) for delivery of volatile metal compounds in gaseous form to processing apparatus has a reaction chamber holding a solid metal source material and connecting to the processing apparatus, and having an outlet for provision of the volatile metal compounds, a source heater coupled to the reaction chamber for heating said solid metal source material, a gas source for providing a reactive gas, a gas delivery conduit from the gas source to the reaction chamber for delivering gas species to the reaction chamber; and a plasma generation apparatus coupled to the gas delivery conduit. The plasma generation apparatus dissociates reactive gas molecules providing monatomic reactive species to the reaction chamber, and the monatomic reactive species combine with metal from the heated solid metal source material forming the volatile metal compounds.

Description

CROSS-REFERENCE TO RELATED DOCUMENTS [0001] This invention was made with government support under contract F33615-99-C-2961 awarded by the US Army Space and Missile Defense Command. The United States Government may therefore have certain rights to this invention.FIELD OF THE INVENTION [0002] The present invention is in the field of CVD processes including Atomic Layer Deposition (ALD), and pertains more particularly to methods and apparatus for preparing at point-of-process and delivering contaminant-free metal precursors in such processes. BACKGROUND OF THE INVENTION [0003] Requirements for ever-thinner thin film deposition, improved uniformity over larger surfaces, and higher production yields have been, and still are, the driving forces behind emerging technologies developed by the research community and commercialized by equipment manufactures for coating wafers to make electronic devices. As these devices become smaller and faster, the need for improved uniformity and better de...

AI Technical Summary

Benefits of technology

[0017] In some applications the solid metal source material is Tantalum and the reactive gas is Chlorine. Further, the gas source may be valved in a manner that rapid pulses of reactive gas are provided to the reaction chamber, providing thereby rapid pulses of the volatile metal compounds at the reaction chamber outlet.

Problems solved by technology

These stringent requirements become more challenging as substrate size increases, sometimes dictating additional chamber design complexity and manifold complications to sustain adequate film uniformity and properties.

Another problem in CVD coating, wherein reactants and the products of reaction coexist in a close proximity to the deposition surface, is the probability of inclusion of reaction products and other contaminants in each deposited layer.

Still further, highly reactive precursor molecules contribute to homogeneous gas phase reactions that can produce unwanted particles, which are detrimental to film quality and device performance.

In the case of CVD, step-coverage typically exceeds typical physical vapor deposition (PVD) performance.

However, certain disadvantages of CVD make ultrathin CVD films inadequate for many emerging critical semiconductor applications.

Likewise, coating high aspect ratio features with conformal CVD films while maintaining film quality and adequate throughput is difficult.

While industry road maps for advanced and future device requirements are fairly well established, some critical applications cannot be realized by existing process technologies.

These temperatures and their maintenance are trivial to maintain throughout passive manifold components such as tubings, diffusers etc.

However, valves that are necessary to produce time controlled pulsed introduction of precursors, which are key for ALD, are typically limited in service temperature, especially when corrosive precursors are involved.

Accordingly, usage of many desired solid precursors poses insurmountable performance and reliability limitations on ALD manifolds deeming them inadequate for semiconductor manufacturing.

Although several solid precursor delivery systems have been proposed and are implemented with more or less success in research and development, there are no known systems, thus far, that are properly suitable for high volume manufacturing.

Existing systems are typically maintenance intensive, low throughput, contaminating and inefficient.

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