Novellus Systems Incorporated

Abhishek Manohar

Raashina Humayun

Feng Chen

Deqi Wang

Panya Wongsenakhum

Yan Guan

Methods of producing low resistivity tungsten bulk layers having low roughness and associated apparatus are provided. According to various embodiments, the methods involve CVD deposition of tungsten at high pressures and/or high temperatures. In some embodiments, the CVD deposition occurs in the presence of alternating nitrogen gas pulses, such that alternating portions of the film are deposited by CVD in the absence of nitrogen and in the presence of nitrogen.

Method for depositing tungsten film with low roughness and low resistivity

Methods of producing low resistivity tungsten bulk layers having lower roughness and higher reflectivity are provided. The smooth and highly reflective tungsten layers are easier to photopattern than conventional low resistivity tungsten films. The methods involve CVD deposition of tungsten in the presence of alternating nitrogen gas pulses, such that alternating portions of the film are deposited by CVD in the absence of nitrogen and in the presence of nitrogen. According to various embodiments, between 20-90% of the total film thickness is deposited by CVD in the presence of nitrogen.

Method for reducing tungsten roughness and improving reflectivity

Improved methods of removing tungsten film from the interior reactor and reactor component surfaces between tungsten deposition operations are provided. The methods involve increasing the availability of molecular fluorine to remove tungsten from the reactor while maintaining fast removal rates. Certain embodiments involve a multi-stage process including a stage in which atomic fluorine is introduced at a low pressure (e.g., about 8 Torr or less) and a stage in which molecular fluorine is introduced or allowed to form in the chamber at high pressure (e.g., about 8 Torr or higher).

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Santa Clara, CA, United States of America

Abhishek Manohar