Method and apparatus for substrate temperature control

• US 20050120805A1
• Filed: 05/03/2004
• Published: 06/09/2005
• Est. Priority Date: 12/04/2003
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Lane, John, Melcer, Chris, Straube, Ralph H.M.
• Application Number:
  US10/838,175
• Publication Number:
  US 20050120805A1
• Time in Patent Office: Days
• US Class Current: 73/861
• CPC Class Codes: C23C 16/45557 Pulsed pressure or control pressure
• CPC Class Codes: C23C 16/466 using thermal contact gas
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow

Abstract

A method and apparatus for gas control is provided. The apparatus may be used for controlling gases delivered to a chamber, controlling the chamber pressure, controlling the delivery of backside gas between a substrate and substrate support and the like. In one embodiment, an apparatus for controlling gas control includes at least a first flow sensor having a control valve, a first pressure sensor and at least a second pressure sensor. An inlet of the first flow sensor is adapted for coupling to a gas supply. A control valve is coupled to an outlet of the flow sensor. The first pressure sensor is adapted to sense a metric indicative of the pressure upstream of the first flow sensor. The second pressure sensor is adapted to sense a metric indicative of the pressure downstream of the control valve.

Claims

1. Apparatus for gas control, comprising:

at least a first flow sensor having an inlet adapted for coupling to a gas supply by a first gas line;

a control valve;

a second gas line coupled to an outlet of the flow sensor and an inlet of the control valve;

a third gas line coupled to an outlet of the control valve;

a upstream pressure sensor coupled to the first gas line and adapted to sense a metric indicative of pressure within the first gas line; and

a downstream pressure sensor coupled to the third gas line and adapted to sense a metric indicative of pressure within the third gas line.

2. The apparatus of claim 1 further comprising:

a bypass line coupled to the third gas line.

3. The apparatus of claim 2, wherein the bypass line further comprises:

a restrictor sized such that flow is choked and proportional to the downstream pressure sensor; and

a bypass valve coupled in parallel.

4. The apparatus of claim 3 further comprising:

a vacuum source coupled in parallel to outlets of the restrictor and bypass valve.

5. The apparatus of claim 4, wherein the vacuum source provides a pressure at least 2 times less than a pressure in the third gas line.

6. The apparatus of claim 1 further comprising:

an intermediate pressure sensor adapted to provide a metric of pressure in the second gas line, wherein a flow of gas passing through the second gas line may be expressed as;

$F_A=F_S+F_{\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>P_S}<br><br>\left(\frac{d<br><br>P_S}{d<br><br>t},V_s\right)-F_P<br><br>\left(\frac{d<br><br>P}{d<br><br>t}\right)$

where;

F_S is the flow sensed by the flow sensor;

P is the pressure sensed in the first gas line;

P_S is the pressure sensed in the second gas line; and

V_S is the volume between flow sensor and the control valve in the second gas line.

7. The apparatus of claim 6 further comprising:

a bypass control branch teed to the third gas line and having a bypass restrictor;

a bypass valve coupled in parallel to the bypass restrictor; and

a vacuum source coupled in parallel to outlets of the bypass restrictor and the bypass valve.

8. The apparatus of claim 1 further comprising:

an intermediate pressure sensor coupled to the second gas line and adapted to sense a metric indicative of pressure within the second gas line and;

9. The apparatus of claim 8, wherein a flow of gas passing through an outlet of the apparatus downstream of the downstream pressure sensor may be expressed as:

F_W=F_A−

F_BLEED(P_W)

where;

F_A is the flow measured by the flow sensor;

F_BLEED is the flow to the vacuum source; and

P_W is the pressure sensed in the third gas line

10. The apparatus of claim 9, wherein the flow of gas to the vacuum source is at least one of measured or factory calibrated.

11. The apparatus of claim 2, wherein the bypass line is disposed downstream of the downstream pressure sensor.

12. The apparatus of claim 2 further comprising:

a bypass pressure sensor coupled to the bypass control branch and adapted to sense a metric indicative of pressure within the bypass control branch.

13. The apparatus of claim 1, wherein the third gas line is coupled to a processing chamber.

14. The apparatus of claim 16, wherein the third gas line is routed through a substrate support disposed in the processing chamber.

15. The apparatus of claim 1, wherein the control valve, the flow sensor, and up to three pressure sensors define a first sub-circuit having a first gas outlet;

and

a second sub-circuit configured substantially identical to the first sub-circuit and having a second gas outlet.

16. The apparatus of claim 15, wherein the outlet of the first sub-circuit is coupled to a first substrate support and the outlet of the second sub-circuit is coupled to a second substrate support.

17. The apparatus of claim 16, wherein the first substrate support is disposed in a different processing chamber than the second substrate support.

18. The apparatus of claim 16, wherein the outlet of the first sub-circuit is coupled to a first backside gas control zone of the first and second substrate supports;

and

the outlet of the second sub-circuit is coupled to a second backside gas control zone of the first and second substrate supports.

19. Apparatus for gas control, comprising:

at least a first control valve having an inlet adapted for coupling to a gas supply;

a flow sensor coupled to an outlet of the control valve;

a first gas line coupled to an outlet of the control valve and the inlet of the flow sensor;

a upstream pressure sensor couple to the first gas line and adapted to sense a metric indicative of pressure within the first gas line.

a second gas line coupled to an outlet of the flow sensor; and

a downstream pressure sensor coupled to the second gas line and adapted to sense a metric indicative of pressure within the second gas line.

20. The apparatus of claim 19 further comprising;

a restrictor disposed in the second gas line;

an intermediate pressure sensor coupled to the second gas line and adapted to sense a metric indicative of pressure within the second gas line upstream of the restrictor;

21. The apparatus of claim 19 further comprising:

a bypass line coupled to the second gas line down stream of the restrictor.

22. The apparatus of claim 21, wherein the bypass line further comprises:

a bypass restrictor; and

a bypass valve coupled in parallel.

23. The apparatus of claim 22 further comprising:

a vacuum source coupled in parallel to outlets of the restrictor and bypass valve.

24. The apparatus of claim 23, wherein the vacuum source provides a pressure at least 2 times less than a pressure in the second gas line.

25. The apparatus of claim 24 further comprising:

an intermediate pressure sensor adapted to provide a metric of pressure in the second gas line, wherein a flow of gas passing through the first gas line may be expressed as;

$F_A=F_S+F_{\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>P_S}<br><br>\left(\frac{d<br><br>P_S}{d<br><br>t},V_s\right)-\mathrm{Fpu}<br><br>\left(\frac{d<br><br>\mathrm{Pu}}{d<br><br>t},\mathrm{Vu}\right)$

where;

F_S is the flow sensed by the flow sensor;

Pu is the pressure sensed in the first gas line;

Vu is the volume between the between the flow sensor and the control valve in the first gas line;

P_S is the pressure sensed in the second gas line; and

V_S is the volume between flow in the second gas line.

26. The apparatus of claim 25 further comprising:

a bypass control branch teed to the second gas line;

a bypass restrictor;

a bypass valve coupled in parallel to the bypass restrictor; and

a vacuum source coupled in parallel to outlets of the bypass restrictor and bypass valve.

27. The apparatus of claim 26, wherein a flow of gas passing through an outlet of the apparatus teed to the second gas line and bypass line may be expressed as:

F_W=F_A−

F_BLEED(P_W)

where;

F_A is the flow measured by the flow sensor; and

F_BLEED is the flow to the vacuum source.

28. The apparatus of claim 27, wherein the flow of gas to the vacuum source is at least one of measured or factory calibrated.

29. The apparatus of claim 27 further comprising:

a restrictor disposed in the second gas line; and

an intermediate pressure sensor coupled to the second gas line and adapted to sense a metric indicative of pressure within the second gas line upstream of the restrictor.

30. The apparatus of claim 22 further comprising an outlet gas line.

31. The apparatus of claim 30, wherein the outlet gas line is coupled to a processing chamber.

32. The apparatus of claim 19, wherein the control valve, the flow sensor, the upstream pressure sensor and the downstream pressure sensor define a first sub-circuit having a first gas outlet;

and

a second sub-circuit configured substantially identical to the first sub-circuit and having a second gas outlet.

33. The apparatus of claim 32, wherein the outlet of the first sub-circuit is coupled to a first substrate support and the outlet of the second sub-circuit is coupled to a second substrate support.

34. The apparatus of claim 32, wherein the first substrate support is disposed in a different processing chamber than the second substrate support.

35. The apparatus of claim 33, wherein the outlet of the first sub-circuit is coupled to a first backside gas control zone of the first and second substrate supports;

and

the outlet of the second sub-circuit is coupled to a second backside gas control zone of the first and second substrate supports.

36. The apparatus of claim 19 further comprising:

a restrictor disposed between the second and downstream pressure sensor.

37. The apparatus of claim 19 further comprising:

a bypass control branch teed between the control valve and the flow sensor;

a bypass restrictor;

a bypass valve coupled in parallel to the bypass restrictor; and

a vacuum source coupled in parallel to outlets of the bypass restrictor and bypass valve.