Reduction of water contamination in a vacuum load lock during pumping from atmosphere

Persistent Link:
http://hdl.handle.net/10150/192041
Title:
Reduction of water contamination in a vacuum load lock during pumping from atmosphere
Author:
Shieh, Jhy-Jer,1956-
Issue Date:
1999
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Rapid pumping causes adiabatic cooling. A dramatic drop in temperature (-35°C) causes the formation of a dense water aerosol in an ordinary vacuum chamber or load lock during routine pumping from atmosphere. In this study we have carefully measured the dynamic temperature response between parallel wafers located in load locks whose time constants are of pratical interest using a unique thermocouple technique. We have also measured the water aerosol formation with particle counters located in the foreline of a load lock as a function of chamber wall spacing. Finally, a model for a load lock which will not transport particles, or cause water vapor condensation has been constructed. This model shows that the water aerosol will not form, if parallel wafers located in the x—y plane are spaced less than or equal to 5 mm apart, and the pump port is located on the (0, 0, z) axis.
Type:
Thesis-Reproduction (electronic); text
LCSH Subjects:
Hydrology.; Water -- Pollution -- Prevention.; Vacuum pumps.
Degree Name:
M.S.
Degree Level:
masters
Degree Program:
Electrical and Computer Engineering; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
O'Hanlon, J. F.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleReduction of water contamination in a vacuum load lock during pumping from atmosphereen_US
dc.creatorShieh, Jhy-Jer,1956-en_US
dc.contributor.authorShieh, Jhy-Jer,1956-en_US
dc.date.issued1999en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractRapid pumping causes adiabatic cooling. A dramatic drop in temperature (-35°C) causes the formation of a dense water aerosol in an ordinary vacuum chamber or load lock during routine pumping from atmosphere. In this study we have carefully measured the dynamic temperature response between parallel wafers located in load locks whose time constants are of pratical interest using a unique thermocouple technique. We have also measured the water aerosol formation with particle counters located in the foreline of a load lock as a function of chamber wall spacing. Finally, a model for a load lock which will not transport particles, or cause water vapor condensation has been constructed. This model shows that the water aerosol will not form, if parallel wafers located in the x—y plane are spaced less than or equal to 5 mm apart, and the pump port is located on the (0, 0, z) axis.en_US
dc.description.notehydrology collectionen_US
dc.typeThesis-Reproduction (electronic)en_US
dc.typetexten_US
dc.subject.lcshHydrology.en_US
dc.subject.lcshWater -- Pollution -- Prevention.en_US
dc.subject.lcshVacuum pumps.en_US
thesis.degree.nameM.S.en_US
thesis.degree.levelmastersen_US
thesis.degree.disciplineElectrical and Computer Engineeringen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairO'Hanlon, J. F.en_US
dc.identifier.oclc221661741en_US
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