Method and equipment for etching substrate characteristic using alternative deposit/etching procedure

Abstract

The present invention provides a method and apparatus for reducing or eliminating notching observed in the creation of SOI structures on substrates during plasma etching by modulating the RF bias applied to the cathode for alternating deposition / etch sequences. Modulation of the bias voltage to the cathode is done separately between at least two frequencies or continuously during the alternating deposition / etch process.

Description

[0001] Cross References to Related Applications [0002] This application claims and relates to its own priority to U.S. Provisional Patent Application Serial No. 60 / 512933, filed October 21, 2003, entitled: Notch-Free Etching of High Aspect SOI Structures Using a Time Division Multiplex Process and RFBias Modulation, at This provisional patent application is hereby incorporated by reference. technical field [0003] The present invention generally relates to the fabrication of silicon-based microelectromechanical systems. More specifically, the invention relates to the fabrication of large aspect ratio silicon structures using alternating deposition and etch steps with modulated RF bias. Background technique [0004] The fabrication of high aspect ratio features in silicon is widely used in the fabrication of microelectromechanical (MEMS) devices. Such features often extend completely across the silicon wafer, and may require 500 μm of overetch deep into the silicon subs...

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Problems solved by technology

[0015] The prior art does not provide the concomitant benefits of the present invention

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