Atomic layer removal process with higher etch amount

Abstract

Higher overall etch rate and throughput for atomic layer removal (ALR) is achieved. The reaction is a self-limiting process, thus limiting the total amount of material that may be etched per cycle. By pumping down the process station between reacting operations, the reaction is partially “reset.” A higher overall etch rate is achieved by a multiple exposure with pump down ALR process.

Description

RELATED APPLICATIONS[0001]This application is a continuation of and claims priority to U.S. application Ser. No. 13 / 244,032, titled “ATOMIC LAYER REMOVAL PROCESS WITH HIGHER ETCH AMOUNT,” filed Sep. 23, 2011, which is a divisional of U.S. patent application Ser. No. 12 / 343,102 (now U.S. Pat. No. 8,058,179), titled “ATOMIC LAYER REMOVAL PROCESS WITH HIGHER ETCH AMOUNT,” filed Dec. 23, 2008, which are incorporated herein by reference for all purposes.FIELD OF THE INVENTION[0002]This invention relates to electronic device fabrication processes and associated apparatus. More specifically, it relates to dry etch processes for removing dielectric films.BACKGROUND OF THE INVENTION[0003]It is often necessary in semiconductor processing to remove or etch dielectric films from a substrate surface. Various etching processes are available to etch different materials and geometries at different rates. Considerations for choosing the appropriate etch process include etch rates, selectivity to oth...

AI Technical Summary

Benefits of technology

The patent text describes a process called atomic layer removal (ALR) etch, which allows for very precise control when removing materials. This process involves reacting a film material with one or more reactants to form a solid reaction product that is then sublimated and removed. The process can be slow, so multiple cycles may be needed to remove a certain amount of material. To increase etch rate, the process is pumped down between reacting operations, which allows for a higher overall etch rate per cycle. The text also describes a gap filling process that uses ALR etch to protect the bottom of a gap from excessive material removal. This process may increase efficiency and protect the fill material from damage during the process. Overall, the patent text explains the technical effects of atomic layer removal and the benefits it can provide for various processes such as etching and gap filling.

Problems solved by technology

The reaction is self-saturating, thus limiting the amount of material that may be etched per cycle.

However, the increase in effectiveness of the “reset” is offset by the increase in total process time—increased duration at reduced pressure may decrease overall etch rate and throughput by increasing total process time.

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