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Method of Enhancing Etch Rate And Selectivity of Refractory Metals

IP.com Disclosure Number: IPCOM000037801D
Original Publication Date: 1989-Jul-01
Included in the Prior Art Database: 2005-Jan-30
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Daubenspeck, TH: AUTHOR

Abstract

By including silicon (Si) wafers coated with boron-phosphorous- silicon glass (BPSG) in a reactive ion etching (RIE) apparatus, etch rate of tungsten (W) is significantly increased while the etch rate of photoresist (PR) remains unchanged. Thus, the etch rate ratio (ERR) of W to PR is increased.

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Method of Enhancing Etch Rate And Selectivity of Refractory Metals

By including silicon (Si) wafers coated with boron-phosphorous- silicon glass (BPSG) in a reactive ion etching (RIE) apparatus, etch rate of tungsten (W) is significantly increased while the etch rate of photoresist (PR) remains unchanged. Thus, the etch rate ratio (ERR) of W to PR is increased.

With there being no gaseous aluminum (Al) reaction products resulting from contact with ionized halogenated hydrocarbon/ oxygen gas normally used for etching W, Al is the construction material usually used in the interior of W RIE systems. Normal ERR of W to PR in a typical RIE system is much less than one. By including at least ten (10) 100 mm diameter BPSG coated Si wafers in the interior of the RIE system during etching, the ERR of W to PR is greater than one. The ERR improvement is entirely due to an increase in W etch rate resulting from the BPSG surface area added to the etching environment.

Disclosed anonymously.

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