Browse Prior Art Database

Flexible System for Controlled Chemical Delivery of Vapors

IP.com Disclosure Number: IPCOM000101702D
Original Publication Date: 1990-Aug-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Barbee, SG: AUTHOR [+4]

Abstract

The integration of three equipment elements, e.g., a liquid flow metering system, an evaporator, and a short heat-traced line, offers a flexible chemical vapor delivery system. This system provides advantages of: 1) controlled delivery over a large flow rate range (0.1 to 1000 sccm), 2) applicability of a single system for pure or multicomponent materials, 3) high reliability, and 4) applicability to a broad range of liquids that may otherwise be impossible to controllably deliver to a reactor.

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Flexible System for Controlled Chemical Delivery of Vapors

       The integration of three equipment elements, e.g., a
liquid flow metering system, an evaporator, and a short heat-traced
line, offers a flexible chemical vapor delivery system.  This system
provides advantages of: 1) controlled delivery over a large flow rate
range (0.1 to 1000 sccm), 2) applicability of a single system for
pure or multicomponent materials, 3) high reliability, and 4)
applicability to a broad range of liquids that may otherwise be
impossible to controllably deliver to a reactor.

      A chemical is stored in a source bottle maintained at a
temperature (T1) slightly above the chemical's melting point (Tmp).
Heating of the source bottle is not required if the chemical is a
liquid at ambient temperature.  Liquid is drawn from the source
bottle at a rate measured by a flowmeter and controlled by a
microprocessor through pumping speed variation.  The source bottle,
liquid pump, and liquid flowmeter are contained within an oven
maintained at a temperature (T2) slightly above the source bottle
temperature (T1).

      Through the action of the fluid metering system, liquid is
transported to the evaporator at a controlled flow rate.  The
evaporator having a temperature (T3) is a high-efficiency
agitated-film unit for flexibility in handling different materials
and minimizing heat transfer boundary layer thickness.  Vapor leaving
the evaporator can be directed first to a vent for fl...