A study of plasma etching for use on active metals

Active metals can be used as a getter pump, removing impurities in ultra-pure high vacuum environments. To relieve the difficulties involved with the transportation, storage and handling of these metals, a process is being developed to create a protective coating by removing the active metal component from the surface of a mixture of the active metal and a stable element via immersion in a wet chemical bath. It is the purpose of this thesis to investigate the utility of a plasma etching process in the removal of the active metal. A decision tree for the selection of a suitable etchant gas was developed and experiments were conducted to validate the process. Magnesium coated glass slides were etched with chlorine, fluorine, and fluorocarbon gasses alone and in the presence of argon to determine which chemistry would etch the fastest. Magnesium was chosen because it was the easiest to handle among the active metals. It was determined that chlorine gas with argon provided the highest etch rate. Next, a set of factorial experiments were conducted to determine the sensitivity of the etch process to changing radio frequency power input, chamber pressure, and the ratio of chlorine to argon.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Nishimoto, Keane T. (Keane Takeshi), 1981-

Advisor dc:contributor.advisor

• Jung-Hoon Chun.

• Mechanical Engineering.

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/1721.1/33914

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/33914