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Liquid Source/Hazardous Chemical Gas Box for Plasma Etchers

IP.com Disclosure Number: IPCOM000040782D
Original Publication Date: 1987-Jan-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Pinto, JN: AUTHOR

Abstract

The system shown in the figure safely delivers liquid chemica to a plasma etch system and eliminates the need for disconnecting gas lines to relieve vapor lock conditions.

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Liquid Source/Hazardous Chemical Gas Box for Plasma Etchers

The system shown in the figure safely delivers liquid chemica to a plasma etch system and eliminates the need for disconnecting gas lines to relieve vapor lock conditions.

Present plasma etch systems use thermal mass flow controllers as a means of metering gas flow. These systems can have a vapor lock which requires a technician to disconnect the line and either pour the liquid out or purge the line with pressurized gas. This operation can expose personnel to the chemical and results in equipment down time.

The system shown in the figure is designed to eliminate the possibility of vapor lock in a mass flow controller by installing a secondary liquid trap or cross purge system design to clear locked gas lines. The cross purge vacuum system can also provide a means by which personnel are protected from exposure to the chemical during cylinder changes.

The normal path from the liquid chemical source through a plasma system mass flow controller is as follows: CONDITION VALVING NORMAL OPERATION V2, V3, V4 and V5 OPEN V1, V6 and V7 CLOSED

In the event of a vapor locked mass flow controller, the following valve settings will purge any condensed vapor in the lines and chambers between the mass flow controller and the vendor filled liquid cylinder valve, V2. The condensed vapor is pumped away by a vacuum pump. CONDITION VALVING VAPOR LOCKED MASS CONTROLLER V1, V2 and V6 CLOSED V3, V4, V5 and V7 OPEN

When a cylind...