Sublimation bed employing carrier gas guidance structures

Abstract

Preferred embodiments of the present invention provides a sublimation system employing guidance structures including certain preferred embodiments having a high surface area support medium onto which a solid source material for vapor reactant is coated. Preferably, a guidance structure is configured to facilitate the repeated saturation of the carrier gas with the solid source for a vapor reactant. Methods of saturating a carrier gas using guidance structures are also provided.

Description

REFERENCE TO RELATED APPLICATION [0001] The present application is a divisional of U.S. patent application Ser. No. 10 / 629,029, filed Jul. 29, 2003, which claims the priority benefit under 35 U.S.C. § 119(e) of Provisional Application No. 60 / 400,210, filed on Jul. 30, 2002, both of which are incorporated herein by reference in their entireties. The present application is related to U.S. patent application Ser. No. 10 / 463,309, filed on Jun. 16, 2003, which is incorporated herein by reference in its entirety.FIELD OF THE INVENTION [0002] The present invention relates generally to the field of substrate fabrication and, more specifically, to semiconductor processing apparatuses designed to effectively vaporize a solid source material. BACKGROUND AND SUMMARY OF THE INVENTION [0003] In the fabrication of integrated circuits on substrates, such as semiconductor wafers, the vapor deposition of chemicals, such as chemical vapor deposition (“CVD”) and more recently atomic layer deposition (A...

AI Technical Summary

Benefits of technology

[0012] A feature of preferred embodiments of the present invention is that a precise and consistent quantity of reactant vapor can be delivered to a deposition chamber at high frequency. An additional feature of the preferred embodiments is an increased ratio of exposed solid source surface area to sublimation vessel volume as a result of, among other factors, the avoidance of problematic “tunneling.” Another feature of preferred embodiments is increased vapor / solid contact time. Yet another feature of preferred embodiments is the allowance of relatively even gas flow resistance over the life of a sublimation bed. Another feature of certain preferred embodiments is the production of a substantially plug flow residence time distribution of the carrier gas substantially saturated with precursor vapor.

Problems solved by technology

Unfortunately, existing semiconductor processing systems, of which a sublimation apparatus is a component, have a number of shortcomings including offering both an inadequate ratio of solid source surface area to vapor volume, and poor vapor / solid contact time.

In addition, a conventional sublimation bed, which seeks to increase vapor / solid contact time, is often prone to “tunneling.” Tunneling results from the tendency of gas to flow preferentially along low resistance paths, rather than through the bulk of the powder, such that progressively smaller solid precursor surface area is exposed to the gas flow as the tunnel through the powder widens.

It is thus progressively more difficult to saturate the carrier gas, even though the sublimation bed contains plenty of unvaporized solid source powder.

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