Piping System And Control For Semiconductor Processing

• US 20100288369A1
• Filed: 05/18/2009
• Published: 11/18/2010
• Est. Priority Date: 05/18/2009
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: CHANG, Yi-Pin, CHERN, Chyi Shyuan
• Granted Patent: US 8,623,141 B2
• Time in Patent Office: Days
• US Class Current: 137/12
• CPC Class Codes: F16K 51/02 specially adapted for high-vacuum installations
• CPC Class Codes: Y10T 137/0379 By fluid pressure
• CPC Class Codes: Y10T 137/86002 Fluid pressure responsive
• CPC Class Codes: Y10T 137/86027 Electric
• CPC Class Codes: Y10T 137/86083 Vacuum pump
• CPC Class Codes: Y10T 137/87684 Valve in each inlet

Abstract

A vacuum system for semiconductor fabrication. The system includes a vacuum chamber for performing a semiconductor fabrication process, a vacuum source, and a piping system fluidly connecting the vacuum chamber to the vacuum source. In one embodiment, the piping system is configured without a horizontal flow path section of piping. In some embodiments, the piping system includes a first piping branch and a second piping branch. The first and second piping branches preferably have a symmetrical configuration with respect to the vacuum source. In yet other embodiments, the first and second piping branches preferably each include a throttle valve.

Claims

1. A vacuum system for semiconductor fabrication comprising:

a vacuum chamber for performing a semiconductor fabrication process;

a vacuum source; and

a piping system fluidly connecting the vacuum chamber to the vacuum source,

wherein the piping is configured without a horizontal flow path section of piping.

2. The system of claim 1, wherein the piping system includes a first piping branch and a second piping branch, the first and second piping branches having a symmetrical configuration with respect to the vacuum source.

3. The system of claim 2, wherein the first and second piping branches have substantially the same configuration.

4. The system of claim 2, wherein each piping branch includes a bifurcated fitting fluidly connected to the vacuum chamber, the bifurcated fitting having two inlet sections and a combined outlet section, the fitting being configured without a horizontal flow path section.

5. The system of claim 1, wherein the piping system includes a first piping branch having a throttle valve and a second piping branch having a throttle valve, the throttle valves each being independently controllable and operable to adjust the pressure in each branch.

6. The system of claim 5, further comprising an isolation valve disposed upstream of the vacuum source and in fluid communication with the first and second piping branches.

7. The system of claim 6, further comprising a bifurcated fitting coupled to each throttle valve and fluidly connected to the vacuum chamber.

8. A vacuum control system for a semiconductor fabrication machine comprising:

a vacuum chamber for performing a semiconductor fabrication process, the chamber including a chamber pressure sensor operable to measure pressure within the chamber and transmit a signal indicative of the measured chamber pressure;

a vacuum source;

a first piping branch fluidly connected to the vacuum chamber and including a first throttle valve, the first branch including a first pressure sensor operable to measure pressure within the first piping branch and transmit a signal indicative of the measured first branch pressure;

a second piping branch fluidly connecting the vacuum chamber and including a second throttle valve, the second piping branch including a second pressure sensor operable to measure pressure within the second piping branch and transmit a signal indicative of the measured second branch pressure;

the first and second piping branches converging and being fluidly connected to the vacuum source; and

a system controller receiving pressure signals from the chamber pressure sensor, first piping branch pressure sensor, and second piping branch pressure sensor, the controller executing control logic configured to;

compare the measured pressure from the first and second piping branch pressure sensors; and

throttle the first or second throttle valves to balance the pressure in each piping branch.

9. The system of claim 8, wherein the control logic is further configured to sense the operating position of the first and second throttle valves, compare the positions of the first and second valve to a control limit, and stop the fabrication machine if the positions of the first or second control valve exceed the control limit.

10. The system of claim 8, wherein the control logic is further configured compare the chamber pressure to the first branch pressure and second branch pressure, and stop the fabrication machine if the first or second branch pressure is not substantially equal to the chamber pressure within a predefined control limit.

11. The system of claim 8, wherein the control logic is stored on computer readable medium accessible to the controller.

12. The system of claim 8, further comprising an isolation valve disposed upstream of the vacuum source and in fluid communication with the first and second piping branches.

13. The system of claim 11, wherein the controller is operable to open or close the isolation valve.

14. A method for controlling a vacuum system for a semiconductor fabrication machine comprising the steps of:

providing a vacuum chamber, a vacuum source, and a piping system fluidly connecting the vacuum chamber to the vacuum source;

measuring pressures in a first and second piping branch of the piping system;

comparing the measured pressures in the first and second piping branches; and

adjusting the pressure in the first or second piping branch.

15. The method of claim 14, wherein the adjusting step includes throttling at least one of a first throttle valve in the first branch and a second throttle valve in the second piping branch.

16. The method of claim 14, further comprising determining the position of the first and second throttle valves and comparing the positions to a predetermined control limit.

17. The method of claim 16, further comprising stopping the fabrication machine if the position of the first or second throttle valves exceeds the control limit.

18. The method of claim 14, further comprising comparing the measured pressures in the first and second piping branches to a pressure measured in the vacuum chamber.

19. The method of claim 18, further comprising stopping the fabrication machine if the measured pressures in the first or second piping branches do not equal the vacuum chamber pressure.

20. The method of claim 14, wherein the steps are automatically performed by a micro-processor based system controller having an associated computer readable medium on which control logic implemented by the controller may be stored which is configured to perform the steps.