Browse Prior Art Database

Cryogenic Pumping Stage for Reactive Ion Etching

IP.com Disclosure Number: IPCOM000039883D
Original Publication Date: 1987-Aug-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Helweg, LW: AUTHOR [+4]

Abstract

Disclosed is a method, utilizing an inline cryogenically cooled trap, for removing contaminant gases from a reactive ion etch (RIE) or sputter deposition process chamber. The method suggests trapping the gasses and reactants in frozen form as they leave the process chamber, isolating the trap, and then removing the contents in a heated form for neutralization and disposal. (Image Omitted) In conventional processing, the use of corrosive gases in an RIE tool used for manufacturing semiconductor devices creates reactants which may attack the components in the path of the process gas stream. Tube filaments, valves, sensors and vacuum pumps are among the items which are subject to attack. The chemicals also retard pumpdown and any water vapor present can react with the chemicals to form additional corrosive materials.

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Cryogenic Pumping Stage for Reactive Ion Etching

Disclosed is a method, utilizing an inline cryogenically cooled trap, for removing contaminant gases from a reactive ion etch (RIE) or sputter deposition process chamber. The method suggests trapping the gasses and reactants in frozen form as they leave the process chamber, isolating the trap, and then removing the contents in a heated form for neutralization and disposal.

(Image Omitted)

In conventional processing, the use of corrosive gases in an RIE tool used for manufacturing semiconductor devices creates reactants which may attack the components in the path of the process gas stream. Tube filaments, valves, sensors and vacuum pumps are among the items which are subject to attack. The chemicals also retard pumpdown and any water vapor present can react with the chemicals to form additional corrosive materials. Referring to Figs. 1 and 2, the disclosed trap consists of a hollow stainless steel cylinder 1 fitted on either side with lock valves 2 for sealing off the trap. Chevron fins 3 (Fig. 3) are arranged internally along the axis of the cylinder so as to maximize the contact of the gas molecules introduced into the trap while minimizing turbulence. Surrounding the cylinder is a liquid nitrogen reservoir 4 to cool the cylinder. It is equipped with fill 5 and drain valves 6 (Fig. 1). A heater 7 is provided to introduce a hot carrier gas which is used to vaporize frozen contaminant gases and exhaust them (8) from...