Evaluation of unsaturated fluorocarbons for dielectric Etch applications

The semiconductor industry is currently faced with the problem of the use and emissions of strong global warming compounds, known as perfluorocompounds (PFCs) for dielectric etch applications. The release of global warming compounds from this and other sources is suspected to result in changes in the earth's climate and weather patterns. Quantitative targets for emissions reduction set by the World Semiconductor Council (WSC) makes it urgent to find a solution to this issue. A long-term means of approaching this problem is to find and develop alternative chemistries that are more environmentally benign without sacrificing performance. Several classes of chemistries have been investigated to date, including hydrofluorocarbons (HFCs), iodofluorocarbons (IFCs), and NF3/hydrocarbons. One class of chemistries that have shown considerable promise is the unsaturated fluorocarbons (UFCs). The research documented herein uses the UFCs to assess etch process and emissions performance. Not only are these novel chemistries tested on conventional silicon dioxide films, but also on new low-k dielectrics that are likely candidates for future generation process flows. Emissions and process performance are reported for each of the different gases. The prospects for integration of some of these chemistries to next generation processes are good from both a process and emissions standpoint. The UFCs are not strong greenhouse gases as a result of their short atmospheric lifetimes (typically less than a day). Unlike many of the previous alternative chemistries studied, the emissions from UFCs are due to reformation of reactive products into strong global warming gases, specifically PFCs and HFCs, in the plasma environment. In this work, the formation of plasma effluents has been studied.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2003

Author dc:creator

• Chatterjee, Ritwik, 1974-

Advisor dc:contributor.advisor

• Rafael Reif.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/86859

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/86859