GAS DISTRIBUTION SYSTEM AND METHOD FOR DISTRIBUTING PROCESS GAS IN A PROCESSING SYSTEM

• US 20090246374A1
• Filed: 03/28/2008
• Published: 10/01/2009
• Est. Priority Date: 03/28/2008
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Vukovic, Mirko
• Granted Patent: US 8,252,114 B2
• Time in Patent Office: Days
• US Class Current: 427/255.280
• CPC Class Codes: C23C 16/45563 Gas nozzles
• CPC Class Codes: C23C 16/45587 Mechanical means for changing the gas flow

Abstract

An apparatus and related method for distributing process gas in a vapor deposition system is described. The gas distribution system includes a vertically movable piston within its plenum, and the movement of the piston controls the flow rate of process gas through the vapor distribution plate of the gas distribution system. The piston can be used to accommodate changes in processing parameters that affect flow characteristics and to create edge-enhanced, uniform, and center-enhanced profiles of deposited material on a substrate without the need to replace the vapor distribution plate.

Claims

1. A gas distribution system configured to be coupled to or within a process chamber for depositing a layer on a substrate, the gas distribution system comprising:

a housing including an inlet and an outer circumferential edge;

a vapor distribution plate coupled to the housing to define a plenum between the inlet and the vapor distribution plate, the vapor distribution plate including a plurality of orifices for distributing a process gas from the plenum to a process space above said substrate; and

a piston disposed in the plenum to define a flow path for the process gas that extends from the inlet to an upper plenum portion between the piston and the outer circumferential edge of the housing and to a lower plenum portion between the piston and the vapor distribution plate;

wherein the piston is vertically movable from an upper position in which the process gas flows uniformly through the plurality of orifices and a lower position in which a process gas flow is greater through an outer radial portion of the plurality of orifices than through a central radial portion of the plurality of orifices.

2. The gas distribution system of claim 1, further comprising a bellows coupled to the piston and the housing for maintaining a vacuum in the gas distribution system.

3. The gas distribution system of claim 2, further comprising a first concentric shield coupled to the piston and a second concentric shield coupled to the housing, wherein the first and second concentric shields overlap and are adjacent to the bellows to prevent particles from the bellows from entering the plenum and the process chamber.

4. The gas distribution system of claim 1, wherein the piston has a flat profile and is oriented substantially parallel to the vapor distribution plate.

5. The gas distribution system of claim 1, wherein the piston has a convex profile oriented towards the vapor distribution plate.

6. The gas distribution system of claim 1, wherein the inlet of the housing includes a gas delivery ring having multiple circumferential orifices for delivering gas adjacent to the outer circumferential edge of the housing.

7. The gas distribution system of claim 1, wherein the plurality of orifices are oriented in a radially uniform pattern.

8. The gas distribution system of claim 7, wherein the piston has a flat profile and is oriented substantially parallel to the vapor distribution plate.

9. The gas distribution system of claim 1, wherein the plurality of orifices are oriented in a radially non-uniform pattern.

10. The gas distribution system of claim 9, wherein the piston has a convex profile oriented towards the vapor distribution plate.

11. The gas distribution system of claim 10, wherein the vapor distribution plate comprises a greater number of orifices in the central radial portion than in the outer radial portion whereby moving the piston to the upper position causes a greater process gas flow through the central radial portion than through the outer radial portion.

12. A method for distributing a process gas into a process chamber of a deposition system comprising:

introducing the process gas into an inlet of a vapor distribution system, wherein the vapor distribution system includes;

a housing including the inlet and an outer circumferential edge,

a vapor distribution plate coupled to the housing to define a plenum between the inlet and the vapor distribution plate, the vapor distribution plate including a plurality of orifices in communication with the process chamber, and

a vertically movable piston disposed in the plenum;

moving the piston to a desired location in the plenum;

flowing the process gas from the inlet to an upper plenum portion between the outer circumferential edge of the housing and the piston and then to a lower plenum portion between the piston and the vapor distribution plate; and

flowing the process gas through the plurality of orifices in the vapor distribution plate into the process chamber, wherein the desired location of the piston determines a relative flow rate of the process gas through an outer radial portion and a central radial portion of the vapor distribution plate.

13. The method of claim 12, wherein the process gas contains a metal-carbonyl precursor vapor.

14. The method of claim 12, wherein the process chamber includes a substrate holder and a substrate, and the method further comprises:

exposing the substrate to the process gas flowing into the process chamber to deposit a layer on the substrate by a chemical vapor deposition process.

15. The method of claim 12, wherein the piston has a flat profile oriented towards the vapor distribution plate and the plurality of orifices in the vapor distribution plate is oriented in a radially uniform pattern, and the moving further comprises:

moving the piston to an upper position so that the piston is about 0.5 inch to about 2.0 inches above the vapor distribution plate to achieve relative uniform flow of the process gas through the outer radial and central radial portions of the vapor distribution plate into the process chamber.

16. The method of claim 12, wherein the piston has a flat profile oriented towards the vapor distribution plate and the plurality of orifices in the vapor distribution plate is oriented in a radially uniform pattern, and the moving further comprises:

moving the piston to a lower position so that the piston is about 0.05 inch to about 0.4 inch above the vapor distribution plate to achieve a higher relative flow of the process gas through the outer radial portion of the vapor distribution plate than through the central radial portion of the vapor distribution plate.

17. The method of claim 12, wherein the piston has a convex profile oriented towards the vapor distribution plate and the plurality of orifices in the vapor distribution plate is oriented in a radially non-uniform pattern comprising more orifices located in the central radial portion of the vapor distribution plate relative to the outer radial portion of the vapor distribution plate, and the moving further comprises:

moving the piston to an upper position so that the piston is about 0.5 inch to about 2.0 inches above the vapor distribution plate to achieve a greater relative flow of the process gas through the central radial portion of the vapor distribution plate than through the outer radial portion of the vapor distribution plate.

18. The method of claim 12, wherein the piston has a convex profile oriented towards the vapor distribution plate and the plurality of orifices in the vapor distribution plate is oriented in a radially non-uniform pattern comprising more orifices located in the central radial portion of the vapor distribution plate relative to the outer radial portion of the vapor distribution plate, and the moving further comprises:

moving the piston to a lower position so that the piston is about 0.05 inch to about 0.4 inch above the vapor distribution plate to achieve relative uniform flow of the process gas through the outer radial and central radial portions of the vapor distribution plate into the process chamber.