Browse Prior Art Database

Method for Reducing Photoresist Etch Rate in NF3 or NF3/AR Plasma Used for RIE or MRIE of Silicon

IP.com Disclosure Number: IPCOM000119791D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 52K

Publishing Venue

IBM

Related People

Lii, YT: AUTHOR

Abstract

Disclosed is a method for reducing etch rate of photoresist during reactive ion etching (RIE) or magnetic enhanced reactive ion etching (MRIE) of silicon in NF3 or NF3/Ar plasma. The method utilizes the polymer enhance agent, such as CHF3, C2F6, C3F8 etc., to reducing photoresist etching rate during silicon etching to form vertical etched profiles.

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Method for Reducing Photoresist Etch Rate in NF3 or NF3/AR Plasma
Used for RIE or MRIE of Silicon

      Disclosed is a method for reducing etch rate of photoresist
during reactive ion etching (RIE) or magnetic enhanced reactive ion
etching (MRIE) of silicon in NF3 or NF3/Ar plasma.  The method
utilizes the polymer enhance agent, such as CHF3, C2F6, C3F8 etc., to
reducing photoresist etching rate during silicon etching to form
vertical etched profiles.

      Control of the etched sidewall angle on VLSI circuits is often
desired.  Plasma etching processes using gases, such as nitrogen
tri-fluoride (NF3), offers fast etch rates and anisotropic etch
profiles (when used with a rare gas such as Ar), so NF3 is a
desirable gas for etching silicon, silicon dioxide, and refractory
metals, and metal silicides. Recently, thinner photoresist (< 1 mm)
became popular for manufacturing submicron devices because of its
high resolution; however, low etch rate ratio of silicon to
photoresist, usually smaller than one, in NF3 or NF3/Ar plasma causes
sloped etched sidewall due to significant photoresist erosion during
etching.

      This method is the introduction of extra polymer enhance
formation agents, such as CHF3, into NF3 or NF3/Ar plasma during
silicon etching to induce a higher passivation rate on the
photoresist mask and to reduce photoresist erosion.  The resist
showed that addition of CHF3 reduces the photoresist erosion.  The
photoresist etch rate is decreasing as...