Browse Prior Art Database

ECO plasma CVD

IP.com Disclosure Number: IPCOM000015169D
Original Publication Date: 2002-Apr-11
Included in the Prior Art Database: 2003-Jun-20
Document File: 2 page(s) / 89K

Publishing Venue

IBM

Abstract

Disclosed is a new PECVD Plasma Enhanced Chemical Vapor Deposition tool which has an intelligent function to suppress PFC Perfluorinated Compound emissions and results in the preservation of global environment, because PFC is one of the sources which cause global warming like CO2 is. PECVD tool is usually using a large amount of PFC to remove the film such as SiO2 deposited on the inside of chamber in order to reduce particles and extend wet clean cycle. This process step is called cleaning step in film deposition cycle used by PECVD tool. Generally, the fixed amount of PFC suited for its deposited film thickness is used for each cleaning steps and the amount is determined to minimize process time in order to obtain the maximum tool capacity from productivity standing point. However, these cleaning step conditions can not always provide minimum PFC emissions. Below chart shows PFC emissions during cleaning step as a function of various amount of PFC after same thickness deposition of SiO2 using PECVD tool.

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ECO plasma CVD

   Disclosed is a new PECVD ( Plasma Enhanced Chemical Vapor Deposition ) tool which has an intelligent function to suppress PFC ( Perfluorinated Compound ) emissions and results in the preservation of global environment, because PFC is one of the sources which cause global warming like CO2 is. PECVD tool is usually using a large amount of PFC to remove the film such as SiO2 deposited on the inside of chamber in order to reduce particles and extend wet clean cycle. This process step is called cleaning step in film deposition cycle used by PECVD tool. Generally, the fixed amount of PFC suited for its deposited film thickness is used for each cleaning steps and the amount is determined to minimize process time in order to obtain the maximum tool capacity from productivity standing point. However, these cleaning step conditions can not always provide minimum PFC emissions. Below chart shows PFC emissions during cleaning step as a function of various amount of PFC after same thickness deposition of SiO2 using PECVD tool.

Condition : pressure 3.0 torr

O2/C2F6 flow ratio 0.8

Optim um condition for various requirem ent

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e

MMTCE : Million Metric Tons carbon Equivalent ( Unit for PFC emissions comparison)

C2F6 : One of PFC used by PECVD tool in its cleaning step

This chart indicates that PFC flow which can minimize MMTCE is not accordance with PFC flow which can minimize process time because the shortest endpoint time means the minimum process time. In above case, a 1100 sccm of C2F6 flow minimizes MMTCE and a 2100 sccm of C2F6 flow minimizes process time. On the other hand, considering fluctuation of production volume, PECVD tool does not always need the minimum process time because lower production volume does not

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MMTCE (x10-9)

Endpoint time (s

500 1000 1500 2000 2500 3000 3500

C 2F6 flow (sccm )

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require its full capacity. Put another way, since less PFC usage causes...