| US 7,594,517 B2 | ||
| Gas supply facility of a chamber and a method for an internal pressure control of the chamber for which the facility is employed | ||
| Hiroshi Kannan, Hachioji (Japan); Tomio Uno, Osaka (Japan); Ryousuke Dohi, Osaka (Japan); Kouji Nishino, Osaka (Japan); Osamu Nakamura, Osaka (Japan); Atsushi Matsumoto, Osaka (Japan); and Nobukazu Ikeda, Osaka (Japan) | ||
| Assigned to Fujikin Incorporated, Osaka (Japan); and Tokyo Electron Ltd., Tokyo (Japan) | ||
| Appl. No. 10/566,495 PCT Filed Jul. 28, 2004, PCT No. PCT/JP2004/010708 § 371(c)(1), (2), (4) Date Jul. 06, 2006, PCT Pub. No. WO2005/013026, PCT Pub. Date Feb. 10, 2005. |
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| Claims priority of application No. 2003-284527 (JP), filed on Jul. 31, 2003. | ||
| Prior Publication US 2007/0193628 A1, Aug. 23, 2007 | ||
| Int. Cl. G05D 7/06 (2006.01) | ||
| U.S. Cl. 137—487.5 [137/601.01; 137/601.14] | 4 Claims |
| 1. A gas supply facility for a chamber, wherein the gas supply facility comprises:
(a) a chamber exhausted by a vacuum pump;
(b) a first pressure type flow controller controlling a small flow rate corresponding to 10% of a maximum flow rate of the
gas supply facility to the chamber;
(b) a second pressure type flow controller controlling a large flow rate corresponding to 90% of the maximum flow rate of
the gas supply facility to the chamber, wherein the second pressure type flow controller is connected in parallel with the
first pressure type flow controller;
(c) a third controller operably connected to control operation of the first pressure type flow controller and the second pressure
type flow controller; wherein
the first pressure type flow controller and the second pressure type flow controller each comprises
i. an orifice;
ii. a pressure detector provided on an upstream side of the orifice;
iii. a control valve provided on an upstream side of the pressure detector; and
iv. a computation control part that computes gas flow rate Qc of gas passing through the orifice using pressure P1 detected by the pressure detector and using formula Qc=KP1, where K is constant, so that a difference Qy with a set flow rate Qs is outputted as a driving signal to the control valve
so that a ratio P1/P2 of pressure P1 on the upstream side of the orifice and pressure P2 on the downstream side of the orifice is maintained at approximately two or more, wherein accurate flow control over a wide
flow rate range is achieved because the first pressure type flow controller controls the small flow rate gas flow rate range
up to 10% of the maximum flow rate supplied to the chamber, while the second pressure type flow controller controls the large
flow rate gas flow rate range of about 10-100% of the maximum flow rate supplied to the chamber; and
wherein the third controller comprises
i. an input setting part that sets the maximum flow rate of gas supplied to the chamber; and
ii. a signal conversion part;
wherein the first pressure type flow controller is initially operated to control small flow rate and when flow rate reaches
10% of the maximum flow rate the second pressure type flow controller is switched into operation, wherein first control signals
for both the first pressure type flow controller and the second pressure type flow controller are provided by the signal conversion
part thereby enabling accurate flow rate control over a wide flow rate range by remitting first control signals from the signal
conversion part to the first pressure type flow controller and the second pressure type flow controller.
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