Novellus Systems Incorporated

Boc, Inc.

Souvik Banerjee

Krishnan Shrinivasan

Harlan Forrest Chung

Raashina Humayun

Sanjay Gopinath

Adrianne K Tipton

Francisco J Juarez

Patrick Christopher Joyce

Karen Ann Reinhardt

Dennis W Hess

Satyanarayana Myneni

A system is provided for cleaning wafers that includes specialized pressurization, process vessel, recirculation, chemical addition, depressurization, and recapture-recycle subsystems. A solvent delivery mechanism converts a liquid-state sub-critical solution to a supercritical cleaning solution and introduces it into a process vessel that contains a wafer or wafers. The supercritical cleaning solution is recirculated through the process vessel by a recirculation system. An additive delivery system introduces chemical additives to the supercritical cleaning solution via the solvent delivery mechanism, the process vessel, or the recirculation system. Addition of chemical additives to the sub-critical solution may also be performed. The recirculation system provides efficient mixing of chemical additives, efficient cleaning, and process uniformity. A depressurization system provides dilution and removal of cleaning solutions under supercritical conditions. A recapture-recycle system introduces captured-purified solvents into the solvent delivery mechanism.

Apparatus and methods for processing semiconductor substrates using supercritical fluids

The present invention is directed to the use of a high vapor pressure liquid prior to or simultaneous with cryogenic cleaning to remove contaminants from the surface of substrates requiring precision cleaning such as semiconductors, metal films, or dielectric films. A liquid suitable for use in the present invention preferably has a vapor pressure above 5 kPa and a freezing point below &#x2212;50&#xb0; C.

Liquid-assisted cryogenic cleaning

The present invention is directed towards the use of a reactive gas or vapor of a reactive liquid prior to or in combination with cryogenic cleaning to remove contaminants from the semiconductor surfaces or other substrate surfaces requiring precision cleaning. The reactive gas or vapor is selected according to the contaminants to be removed and the reactivity of the gas or vapor with the contaminants. Preferably, this reaction forms a gaseous byproduct which is removed from the substrate surface by the flow of nitrogen across the surface.

Vapor-assisted cryogenic cleaning

A method of delivering a reagent to a wafer is provided. A solvent is provided. A set of conditions of temperature and pressure is provided to the solvent, which is sufficient to bring the solvent to supercritical conditions. A reagent is provided. A surfactant is provided, where the surfactant has a first moiety with an affinity for the solvent and a second moiety with an affinity for the reagent, where the surfactant increases the concentration of the reagent that may be carried by the solvent. The solvent, surfactant, and reagent are combined to form a solution. The solution is delivered to a supercritical process chamber, wherein a wafer is exposed to the solution in the process chamber.

Method and apparatus for using surfactants in supercritical fluid processing of wafers

The present invention pertains to a system for cleaning wafers that includes specialized pressurization, process vessel, recirculation, chemical addition, depressurization, and recapture-recycle subsystems, as well as methods for implementing wafer cleaning using such a system. A solvent delivery mechanism converts a liquid-state sub-critical solution to a supercritical cleaning solution and introduces it into a process vessel that contains a wafer or wafers. The supercritical cleaning solution is recirculated through the process vessel by a recirculation system. An additive delivery system introduces chemical additives to the supercritical cleaning solution via the solvent delivery mechanism, the process vessel, or the recirculation system. Addition of chemical additives to the sub-critical solution may also be performed. The recirculation system provides efficient mixing of chemical additives, efficient cleaning, and process uniformity. A depressurization system provides dilution and removal of cleaning solutions under supercritical conditions. A recapture-recycle system introduces captured-purified solvents into the solvent delivery mechanism.

Methods for cleaning semiconductor wafers are presented. Contaminants, particularly photoresist and post-etch residue, are removed from semiconductor wafers. A wafer or wafers is first treated with a peroxide-containing medium, for example, to oxidatively cleave bond structures of contaminants on the wafer work surface. Excitation energy is used to activate the peroxide-containing medium toward the formation of radical species. After treatment with the peroxide-containing medium, a supercritical fluid treatment is used to remove any remaining contaminants as well as to condition the wafer for subsequent processing.

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Fremont, CA, United States of America

Souvik Banerjee