Gas distribution apparatus for semiconductor processing

• US 6,415,736 B1
• Filed: 06/30/1999
• Issued: 07/09/2002
• Est. Priority Date: 06/30/1999
• Status: Expired due to Term

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Dhindsa, Rajinder, Hao, Fangli
• Primary Examiner(s): Mills, Gregory
• Assistant Examiner(s): HASSANZADEH, PARVIZ
• Application Number:
  US09/343,481
• Time in Patent Office: 1,105 Days
• Field of Search: 118/715, 118/723.VE, 118/723.R, 118/723.E, 156/345
• US Class Current: 118/723.00E
• CPC Class Codes: H01L 21/67017 Apparatus for fluid treatment H01L21/67126, H01L21/6715 take precedence

Abstract

A gas distribution system for semiconductor processing includes a contoured surface to achieve a desired gas distribution on the backside of a showerhead. The system can include one or more gas supplies opening into a plenum between a baffle plate and a temperature-controlled support member. The baffle plate can have a nonuniform thickness and geometry-controlled openings to achieve a desired gas distribution. In one arrangement the baffle plate is conical in shape with uniform diameter holes extending different distances through the baffle plate to achieve a uniform pressure of gas through outlets in a planar bottom surface of the baffle plate. In another arrangement, the holes have progressively larger diameters in a direction away from the location of the centrally located gas supply outlet. The shape of the baffle plate and/or configuration of the holes can be designed to achieve a desired gas pressure distribution.

Claims

1. A gas distribution system useful for semiconductor substrate processing, comprising:

a support body;

a gas distribution chamber;

a gas supply inlet through which pressurized process gas flows into the gas distribution chamber;

a showerhead supported by the support body such that pressurized process gas in the gas distribution chamber applies pressure to a backside of the showerhead and passes through openings extending between the backside and an opposite side of the showerhead, the showerhead being a showerhead electrode of a plasma chamber; and

a contoured surface in the gas distribution chamber, the contoured surface being effective to provide a desired gas pressure distribution at the backside of the showerhead electrode, and wherein the contoured surface comprises a nonplanar upper and/or lower surface of a baffle plate having openings therethrough and the gas distribution chamber comprises an upper plenum above the baffle plate and a lower plenum below the baffle plate.

2. The gas distribution system of claim 1, wherein the baffle plate has uniformly sized openings extending between the upper and lower surfaces, the openings having shorter lengths in a central portion of the baffle plate and longer lengths in an outer portion of the baffle plate.

3. The gas distribution system of claim 1, wherein the baffle plate is integral with the support body, the upper plenum is enclosed by an upper sidewall of the support body and a cover plate which seals against the upper sidewall, and the lower plenum is enclosed by a lower sidewall of the support body and the showerhead which seals against the lower sidewall.

4. The gas distribution system of claim 1, wherein the openings become progressively larger at locations away from the gas supply inlet.

5. The gas distribution system of claim 1, wherein the baffle plate has a conical shape, the openings have the same diameters and the openings have different lengths through the baffle plate.

6. The gas distribution system of claim 1, wherein at least some of the outlets are tapered.

7. A gas distribution system useful for semiconductor substrate processing, comprising:

a support body;

a gas distribution chamber;

a gas supply inlet through which pressurized process gas flows into the gas distribution chamber,

a showerhead supported by the support body such that pressurized process gas in the gas distribution chamber applies pressure to a backside of the showerhead and passes through openings extending between the backside and an opposite side of the showerhead, the showerhead being a showerhead electrode of a plasma chamber; and

a contoured surface in the gas distribution chamber, the contoured surface being effective to provide a desired gas pressure distribution at the backside of the showerhead electrode wherein the contoured surface is a nonplanar lower surface of the support body and the gas distribution chamber comprises an open space between the contoured surface and the backside of the showerhead wherein the showerhead is spaced closer to the contoured surface in the vicinity of the gas supply inlet and further from the contoured surface at locations away from the gas supply inlet.

8. The gas distribution system of claim 7, wherein the gas inlet supplies process gas through an annular channel which opens into an outer region of the open space and the showerhead is spaced closer to the contoured surface in the outer region and further from the contoured surface in a central region of the open space.

9. A gas distribution system useful for semiconductor substrate processing, comprising:

a support body;

a gas distribution chamber;

a gas supply inlet through which pressurized process gas flows into the gas distribution chamber;

a showerhead supported by the support body such that pressurized process gas in the gas distribution chamber applies pressure to a backside of the showerhead and passes through openings extending between the backside and an opposite side of the showerhead; and

a contoured surface in the gas distribution chamber, the contoured surface being effective to provide a desired gas pressure distribution at the backside of the showerhead, the contoured surface comprising a nonplanar upper and/or lower surface of a baffle plate having openings therethrough and the gas distribution chamber comprising an upper plenum above the baffle plate and a lower plenum below the baffle plate, the gas inlet supplying the process gas through a central opening in a planar surface facing the baffle plate, the baffle plate having a thickness which is larger in a central portion of the baffle plate and smaller at an outer portion of the baffle plate.

10. A gas distribution system useful for semiconductor substrate processing, comprising:

a support body;

a gas distribution chamber;

a gas supply inlet through which pressurized process gas flows into the gas distribution chamber;

a showerhead supported by the support body such that pressurized process gas in the gas distribution chamber applies pressure to a backside of the showerhead and passes through openings extending between the backside and an opposite side of the showerhead; and

a contoured surface in the gas distribution chamber, the contoured surface being effective to provide a desired gas pressure distribution at the backside of the showerhead, the contoured surface comprising a nonplanar upper and/or lower surface of a baffle plate having openings therethrough and the gas distribution chamber comprising an upper plenum above the baffle plate and a lower plenum below the baffle plate, the gas inlet supplying the process gas through an inlet which opens into an outer region of the upper plenum, the baffle plate having a thickness which is smaller in a central portion of the baffle plate and larger at an outer portion of the baffle plate.

11. A gas distribution system useful for semiconductor substrate processing, comprising:

a support body;

a gas distribution chamber;

a gas supply inlet through which pressurized process gas flows into the gas distribution chamber;

a showerhead supported by the support body such that pressurized process gas in the gas distribution chamber applies pressure to a backside of the showerhead and passes through openings extending between the backside and an opposite side of the showerhead; and

a contoured surface in the gas distribution chamber, the contoured surface being effective to provide a desired gas pressure distribution at the backside of the showerhead, the contoured surface comprising a nonplanar upper and/or lower surface of a baffle plate having openings therethrough and the gas distribution chamber comprising an upper plenum above the baffle plate and a lower plenum below the baffle plate, the baffle plate having uniformly sized openings extending between the upper and lower surfaces, the openings having longer lengths in a central portion of the baffle plate and shorter lengths in an outer portion of the baffle plate.

12. A gas distribution system useful for semiconductor substrate processing, comprising:

a support body;

a gas distribution chamber;

a gas supply inlet through which pressurized process gas flows into the gas distribution chamber;

a showerhead supported by the support body such that pressurized process gas in the gas distribution chamber applies pressure to a backside of the showerhead and passes through openings extending between the backside and an opposite side of the showerhead; and

a contoured surface in the gas distribution chamber, the contoured surface being effective to provide a desired gas pressure distribution at the backside of the showerhead, the contoured surface being a nonplanar lower surface of the support body and the gas distribution chamber comprising an open space between the contoured surface and the backside of the showerhead, the gas inlet supplying the process gas through a central opening in the lower surface of the support body and the open space being smaller in a central region thereof and larger in an outer region thereof.

13. A gas distribution system useful for semiconductor substrate processing, comprising:

a support body;

a gas distribution chamber;

a gas supply inlet through which pressurized process gas flows into the gas distribution chamber;

a showerhead supported by the support body such that pressurized process gas in the gas distribution chamber applies pressure to a backside of the showerhead and passes through openings extending between the backside and an opposite side of the showerhead; and

a contoured surface in the gas distribution chamber, the contoured surface being effective to provide a desired gas pressure distribution at the backside of the showerhead, the contoured surface comprising a nonplanar upper and/or lower surface of a baffle plate having openings therethrough and the gas distribution chamber comprising an upper plenum above the baffle plate and a lower plenum below the baffle plate, the support body including at least one coolant channel in which coolant can be circulated.

14. A gas distribution system useful for semiconductor substrate processing, comprising:

a support body;

a gas distribution chamber;

a gas supply inlet through which pressurized process gas flows into the gas distribution chamber;

a showerhead supported by the support body such that pressurized process gas in the gas distribution chamber applies pressure to a backside of the showerhead and passes through openings extending between backside and an opposite side of the showerhead; and

a contoured surface in the gas distribution chamber, the contoured surface being effective to provide a desired gas pressure distribution at the backside of the showerhead, the contoured surface comprising a nonplanar upper and/or lower surface of a baffle plate having openings therethrough and the gas distribution chamber comprising an upper plenum above the baffle plate and a lower plenum below the baffle plate, the support body including a second gas supply inlet which supplies process gas that passes through the baffle plate.

15. A gas distribution system useful for semiconductor substrate processing, comprising:

a support body;

a gas distribution chamber;

a gas supply inlet through which pressurized process gas flows into the gas distribution chamber;

a showerhead supported by the support body such that pressurized process gas in the gas distribution chamber applies pressure to a backside of the showerhead and passes through openings extending between the backside and an opposite side of the showerhead; and

a contoured surface in the gas distribution chamber, the contoured surface being effective to provide a desired gas pressure distribution at the backside of the showerhead, the contoured surface comprising a nonplanar upper and/or lower surface of a baffle plate having openings therethrough and the gas distribution chamber comprising an upper plenum above the baffle plate and a lower plenum below the baffle plate, the openings having the same diameters and the openings having progressively shorter lengths at locations away from the gas supply inlet.

16. A gas distribution system useful for semiconductor substrate processing, comprising:

a support body;

a gas distribution chamber;

a gas supply inlet through which pressurized process gas flows into the gas distribution chamber;

a showerhead supported by the support body such that pressurized process gas in the gas distribution chamber applies pressure to a backside of the showerhead and passes through openings extending between the backside and an opposite side of the showerhead; and

a contoured surface in the gas distribution chamber, the contoured surface being effective to provide a desired gas pressure distribution at the backside of the showerhead, the contoured surface comprising a nonplanar upper and/or lower surface of a baffle plate having openings therethrough and the gas distribution chamber comprising an upper plenum above the baffle plate and a lower plenum below the baffle plate, the openings at a peripheral portion of the baffle plate having larger diameters than the openings proximate a central region of the baffle plate.

17. A gas distribution system useful for semiconductor substrate processing, comprising:

a support body;

a gas distribution chamber;

a gas supply inlet through which pressurized process gas flows into the gas distribution chamber;

a showerhead supported by the support body such that pressurized process gas in the gas distribution chamber applies pressure to a backside of the showerhead and passes through openings extending between the backside and an opposite side of the showerhead; and

a contoured surface in the gas distribution chamber, the contoured surface being effective to provide a desired gas pressure distribution at the backside of the showerhead, the contoured surface comprising a nonplanar upper and/or lower surface of a baffle plate having openings therethrough and the gas distribution chamber comprising an upper plenum above the baffle plate and a lower plenum below the baffle plate, at least some of the openings having diameters which change along the length of the openings.