INTERNAL PRESSURE CONTROLLER OF CHAMBER AND INTERNAL PRESSURE SUBJECT -TO- CONTROL TYPE CHAMBER

• US 20060207595A1
• Filed: 04/06/2006
• Published: 09/21/2006
• Est. Priority Date: 10/06/2003
• Status: Active Grant

• Current Assignee: Fujikin Incorporated, Tadahiro Ohmi
• Original Assignee: Fujikin Incorporated, Tadahiro Ohmi
• Inventors: MATSUMOTO, Atsushi, NAKAMURA, Osamu, DOHI, Ryousuke, NISHINO, Kouji, NAGASE, Masaaki, OHMI, Tadahiro, TERAMOTO, Akinobu, UNO, Tomio, IKEDA, Nobukazu
• Granted Patent: US 7,798,167 B2
• Time in Patent Office: Days
• US Class Current: 128/205.260
• CPC Class Codes: G05D 16/208 using a combination of controlling means as defined in G05D16/2013 and G05D16/2066 G05D16/2073 takes precedence
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve
• CPC Class Codes: Y10T 137/8741 With common operator
• CPC Class Codes: Y10T 137/87507 Electrical actuator

Abstract

A gas supply facility includes a plurality of pressure type flow controllers connected in parallel, and a first controller to control operation of the plurality of pressure type flow controllers so as to supply a desired gas exhausted by a vacuum pump to a chamber while controlling its flow rate, one of the pressure type flow controllers operates as a second controller to control the gas flow rate range up to 10% of the maximum flow rate supplied to the chamber, while the remaining pressure type flow controllers are made to be ones that control the rest of the gas flow rate range. Furthermore, pressure inside the chamber is controlled by installing a pressure detector in the chamber, inputting the value detected by the detector to the controller, and by adjusting a control signal to the pressure type flow controllers.

Claims

1. An internal pressure controller of a chamber, comprising:

(a) a supply gas input part;

(b) a supply gas output part connected to receive supply gas from the supply gas input part;

(c) a gas flow rate control part operably connected between the gas input part and gas output part;

(d) a chamber connected to receive supply gas from the supply gas output part; and

(e) a means to transmit pressure data of the chamber to the gas flow rate control part, and the gas flow rate control part includes

i. a plurality of pressure type flow rate controllers connected in parallel; and

ii. a first controller operable to control the operation of the plurality of pressure type flow controllers, wherein each pressure type flow controller comprises an orifice, a pressure detector on an upstream side of the orifice, a control valve provided on the upstream side of the pressure detector, and a computation control part that outputs a difference Qy with a set flow rate Qs as a driving signal to the control valve by computing a gas flow rate Qc passing through the orifice with pressure P₁ detected by the pressure detector using formula Qc=KP₁, where K is a constant, thus operating a respective one of the pressure type flow controllers under a state wherein pressure P₁ is maintained more than approximately 2 times of pressure P₂ on the downstream side of the orifice, and at the same time, one of the plurality of pressure type flow controllers is operated as a second controller controlling the gas flow rate range up to 10% of the maximum flow rate supplied to the chamber while the remaining pressure type flow controllers are operated as third controllers controlling the rest of the gas flow rate range, and pressure data is inputted to the first controller to adjust a control signal to each pressure type flow controller so as to control gas flow rate to the supply gas output part.

2. An internal pressure controller of a chamber as claimed in claim 1, wherein the first controller comprises:

an input setting part to set gas flow rate supplied to the chamber;

a first signal conversion part that operates to convert an input value to the input setting part into a flow rate control signal;

a second signal conversion part that operates to convert detected pressure inside the chamber to a flow rate control signal; and

a comparison correction part operably connected to receive flow rate control signals from both the first signal conversion part and the second signal conversion part so the first controller controls a supply volume of supply gas into the chamber by transmitting corrected control signals to all of the pressure type flow controllers from the comparison correction part.

3. An internal pressure controller of a chamber as claimed in claim 1, wherein the plurality of pressure type flow controllers include 2 pressure type flow controllers connected in parallel, and one of these two pressure type flow controllers operates to control a small flow quantity range, while the other one of these two pressure type flow controllers operates to control a large flow quantity range.

4. An internal pressure controller of a chamber as claimed in claim 3, wherein the flow rate control range of the pressure type flow controller controlling the small flow quantity range is 0.1 to 10% of a maximum flow rate supplied to the chamber while the flow rate control range of the pressure type flow controller controlling the large flow quantity range is 10 to 100% of the maximum flow rate supplied to the chamber.

5. An internal pressure controller of a chamber as claimed in claim 3, wherein the plurality of pressure type flow controllers are controlled to operate starting with the pressure type flow controller for the smaller flow quantity range in turn due to control signals transmitted from the signal conversion part of the controller.

6. An internal pressure controller of a chamber as claimed in claim 1, wherein the chamber includes an evacuation system, and an exhaust velocity of the evacuation system is made to vary due to supply gas flowed into the evacuation system.

7. An internal pressure controller of a chamber as claimed in claim 1, wherein a plurality of supply gases is supplied to the chamber by installing a plurality of pressure type flow controllers connected in parallel, wherein the plurality of pressure type flow controllers includes at least 4 units.

8. An internal pressure controller of a chamber as claimed in claim 3, wherein a plurality of supply gases is supplied to the chamber by installing a plurality of supply gas facilities connected in parallel, wherein the plurality of supply gas facilities include at least 4 units, wherein a first supply gas facility includes the two pressure type flow controllers connected in parallel, and each of the remaining supply gas facilities includes two second pressure type flow controllers, wherein one of the two second pressure type flow controllers operates to control a small flow quantity range, while the other one of the two second pressure type flow controllers operates to control a large flow quantity range.

9. An internal pressure controller of a chamber as claimed in claim 2, wherein the input setting part comprises a rising rate setting mechanism for initiating control signals transmitted to pressure type flow controllers allotted for all the flow rate ranges, and the pressure type flow controllers supply the set flow rate of gas after a specified lapse of time following transmission of the control signals initiated by the rising rate setting mechanism.

10. An internal pressure subject-to-control type chamber comprising:

(a) a chamber exhausted by a vacuum pump; and

(b) a gas supply means for supplying a desired gas while controlling flow rate of the gas, wherein the gas supply means comprises

i. a plurality of pressure type flow controllers connected in parallel; and

ii. a first controller operable to control the operation of the plurality of pressure type flow controllers, wherein the first controller comprises an orifice, a pressure detector on an upstream side of the orifice, a control valve provided on the upstream side of the pressure detector, and a computation control part that outputs a difference Qy with a set flow rate Qs as a driving signal to the control valve by computing a gas flow rate Qc passing through the orifice with pressure P₁ detected by the pressure detector using formula Qc=KP₁, where K is a constant, thus operating each pressure type flow controller under a state wherein pressure P₁ is maintained more than 2 times of pressure P₂ on the downstream side of the orifice, and at the same time, one of the plurality of pressure type flow controllers is operated as a second controller controlling the gas flow rate range up to 10% of the maximum flow rate supplied to the chamber while the remaining pressure type flow controllers control the rest of the flow rate ranges, and the chamber is further provided with a pressure detector, and a detected value of the pressure detector is inputted to the first controller to adjust a control signal transmitted to the pressure type flow controllers and to control the supply rate of gas to the chamber so internal pressure of the chamber is controlled with high accuracy over the wide range.