US5520969A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for in-situ liquid flow rate estimation and verification
Assignee: Applied Materials Inc
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Filing: 1994-02-04
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Granted: 1996-05-28
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Expires: 2014-02-04
Abstract
Abstract The flow of a liquid reagent gas into a vapor deposition process chamber is adjusted in response to control information provided by a process controller. The controller executes a prescribed mathematical algorithm which utilizes first and second steady-state pressure differentials. The first pressure differential is measured during the flowing of a carrier gas into the chamber. The second pressure differential is measured after the release of the liquid reagent into the chamber.
Inventors
- 👤 Hiroshi Nishizato
- 👤 Visweswaren Sivaramakrishnan
- 👤 Jun Zhao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:37
CPC Classifications
G; G05; G05D; G05D7/00; G05D7/06; G05D7/0617; G05D7/0629; G05D7/0635; G05D7/0641; G05D7/0658; C; C23; C23C; C23C16/00; C23C16/44; C23C16/448; C23C16/4481; C23C16/52; G05D11/00; G05D11/02; G05D11/13; G05D11/135
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
116 words
A method of controlling a liquid mass flow rate of a liquid reagent into a vapor deposition process chamber, the method comprising: flowing a carrier gas into the chamber; measuring a first steady-state pressure of the chamber with the carrier gas flowing into the chamber; flowing the liquid reagent into the flow of carrier gas for delivery of the liquid reagent into the chamber in a vaporized state; measuring a second steady-state pressure of the chamber while the carrier gas is delivering the vaporized liquid reagent to the chamber; computing control information from the first and second steady-state pressures; and controlling the liquid mass flow rate of the liquid reagent in response to the control information.
Claim 2
Independent Claim
116 words
A method of controlling a liquid mass flow rate of a liquid reagent into a vapor deposition process chamber, the method comprising: flowing a carrier gas into the chamber; measuring a first steady-state pressure of the chamber with the carrier gas flowing into the chamber; flowing the liquid reagent into the flow of carrier gas for delivery of the liquid reagent into the chamber in a vaporized state; measuring a second steady-state pressure of the chamber while the carrier gas is delivering the vaporized liquid reagent to the chamber; computing control information from the first and second steady-state pressures; and controlling the liquid mass flow rate of the liquid reagent in response to the control information.
Claim 3
Dependent Claim
59 words
The method of claim 1 further comprising: establishing a base pressure in the process chamber prior to flowing said carrier gas into the chamber; and after establishing a base pressure in said chamber, measuring said base pressure, wherein the computing step comprises using the measured base pressure and the first and second steady-state pressures to compute said control information.
Claim 4
Dependent Claim
54 words
The method of claim 2 wherein the computing step comprises: determining a pressure ratio, R, by computing ##EQU3## where P0 is the measured base pressure, P1 is the first steady-state pressure, and P2 is the second steady-state pressure; using R to compute a calibration constant, C; and using C to generate the control information.
Claim 5
Dependent Claim
34 words
The method of claim 3 wherein the step of using R to compute the calibration constant, C, comprises calculating ##EQU4## wherein Ro is a pressure ratio offset and Re is an expected pressure ratio.
Claim 6
Dependent Claim
28 words
The method of claim 4 further comprising determining Ro and Re during an initialization procedure that is performed using said deposition chamber prior to performing the aforementioned steps.
Claim 7
Dependent Claim
71 words
The method of claim 5 wherein the step of determining Ro comprises: determining a first pressure ratio, Re1, for a first liquid mass flow rate, Q1, of said liquid reagent into process chamber in a vaporized state; determining a second pressure ratio, Re2, for a second liquid mass flow rate, Q2, of said liquid reagent into the process chamber in a vaporized state; and computing Ro from the following relationship: ##EQU5##
Claim 8
Dependent Claim
70 words
The method of claim 3 wherein the computing step comprises: determining a pressure ratio, R, by computing ##EQU6## where P0 is the first steady-state pressure, P1 is the second steady-state pressure, and P2 is the third steady-state pressure; and comparing R to an expected pressure ratio, Re; wherein the controlling step comprises adjusting the liquid mass flow rate if R deviates from Re by more than a predetermined threshold amount.
Claim 9
Dependent Claim
31 words
The method of claim 7 wherein the controlling step further comprises refraining from adjusting the liquid mass flow rate if R deviates from Re by less than the predetermined threshold amount.
Claim 10
Dependent Claim
67 words
The method of claim 1 wherein the step of flowing the liquid reagent into the flowing carrier gas for delivery of the liquid reagent into the chamber in a vaporized state comprises: flowing the liquid reagent into a vaporizer; within the vaporizer, using the flowing carrier gas to vaporize the liquid reagent that is flowed into the vaporizer; and supplying the vaporized liquid reagent to the chamber.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-05-28 | 1999-11-27 | 2000-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-05-28 | 2003-11-27 | 2004-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-05-28 | 2007-11-27 | 2008-05-28 | $7700.00 | Window Closed / Lapsed |