Claims
- 1. A vaporizer for vaporizing a liquid and mixing the vaporized liquid with a carrier gas, comprising:
a valve body defining a control valve cavity having first, second and third apertures, a gas inlet port connected to said first aperture through a first fluid channel for receiving said carrier gas at a given pressure, a liquid inlet port connected to said second aperture through a second fluid channel for receiving said liquid at a flow rate and a pressure above said given pressure, a closure element disposed adjacent to said second aperture for forming a vaporization region having a pressure gradient, said vaporization region circumscribing said liquid inlet port and having a substantially larger width than said inlet port, and an outlet port connected to said third aperture through a third fluid channel, wherein liquid supplied through said liquid inlet port vaporizes in said valve cavity to form a vaporized liquid, mixes with said carrier gas, and is carried out of said vaporizer through said outlet port.
- 2. The vaporizer of claim 1, wherein
said closure element is a diaphragm movable relative to said second aperture to increase or decrease said flow rate and further comprising an actuator for moving said diaphragm toward and away from said second aperture in response to a control signal.
- 3. The vaporizer of claim 2, further comprising
a liquid flow meter connected to measure the flow rate of liquid into said liquid inlet port, a feedback control system for providing said control signal in response to a flow rate measured by said liquid flow meter so as to regulate the flow rate of the liquid to approximate a selected value.
- 4. The vaporizer of claim 2, wherein said actuator is a piezoelectric member responsive to said control signal.
- 5. The vaporizer of claim 1 further comprising a heater for heating at least a portion of said valve body near to said cavity so as to inhibit said liquid from condensing after it has vaporized.
- 6. The vaporizer of claim 2 further comprising a heater for heating at least a portion of said valve body near to said cavity so as to inhibit said liquid from condensing after it has vaporized.
- 7. The vaporizer of claim 3 further comprising a heater for heating at least a portion of said valve body near to said cavity so as to inhibit said liquid from condensing after it has vaporized.
- 8. A chemical vapor deposition system using a liquid reactant and a carrier gas, comprising:
a chemical vapor deposition chamber having a gas inlet port, and a liquid reactant vaporizer having an outlet port connected to said chamber inlet port, said vaporizer comprising:
a valve body defining a control valve cavity having first, second and third apertures, said outlet port connected to said third aperture through a first fluid channel, a gas inlet port connected to said first aperture through a second fluid channel for receiving said carrier gas at a given pressure, a liquid inlet port connected to said second aperture through a third fluid channel for receiving said liquid reactant at a flow rate and a pressure above said given pressure, a diaphragm disposed adjacent to said second aperture for forming a vaporization region having a pressure gradient, said vaporization region circumscribing said liquid inlet port and having a substantially larger width than said inlet port, and wherein liquid reactant supplied through said liquid inlet port vaporizes in said valve cavity to form a vaporized reactant, mixes with said carrier gas, and is carried out of said vaporizer through said outlet port.
- 9. The chemical vapor deposition system of claim 6, wherein said diaphragm is movable relative to said second aperture, and further comprising
an actuator for moving said diaphragm toward and away from said second aperture in response to a control signal, a liquid mass flow monitor coupling said liquid reactant to said liquid inlet port for measuring a mass flow rate of said liquid reactant and generating an electrical mass flow signal indicating said mass flow rate, and electrical control means for comparing said mass flow signal to a set point, for signalling said actuator to move said diaphragm toward said second aperture when said mass flow signal indicates a flow rate above said set point, and for exciting said actuator to move said diaphragm away from said second aperture when said mass flow signal indicates a flow rate below said set point.
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to previously-filed U.S. patent application Ser. No. 07/912,024, filed Jul. 9, 1992, which is a continuation of Ser. No. 07/626,274, now abandoned.
Divisions (1)
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Parent |
08574999 |
Dec 1995 |
US |
Child |
09660208 |
Sep 2000 |
US |
Continuations (3)
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09660208 |
Sep 2000 |
US |
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10305827 |
Nov 2002 |
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08278984 |
Jul 1994 |
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08574999 |
Dec 1995 |
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07990755 |
Dec 1992 |
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Child |
08278984 |
Jul 1994 |
US |