Gas distribution apparatus for improved film uniformity in an epitaxial system

• US 10,501,866 B2
• Filed: 01/19/2017
• Issued: 12/10/2019
• Est. Priority Date: 03/09/2016
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM IP Holding B.V. (ASM International NV)
• Inventors: Coomer, Stephen Dale, Vyne, Robert, Bergman, Timo, Bode, Lee, Wang, Wentao
• Primary Examiner(s): Zervigon, Rudy
• Application Number:
  US15/410,503
• Publication Number:
  US 20170260649A1
• Time in Patent Office: 1,055 Days
• Field of Search: 118715, 15634533, 15634534
• CPC Class Codes: C23C 16/45561 Gas plumbing upstream of the reaction chamber
• CPC Class Codes: C23C 16/45582 Expansion of gas before it reaches the substrate
• CPC Class Codes: C23C 16/45587 Mechanical means for changing the gas flow
• CPC Class Codes: C30B 25/14 Feed and outlet means for the gases; Modifying the flow of the reactive gases
• CPC Class Codes: C30B 25/165 the flow of the reactive gases

Abstract

A gas distribution system is disclosed in order to obtain better film uniformity on a wafer. The better film uniformity may be achieved by utilizing an expansion plenum and a plurality of, for example, proportioning valves to ensure an equalized pressure or flow along each gas line disposed above the wafer.

Claims

1. A reaction system for processing a substrate, comprising:

a reaction chamber, the reaction chamber holding a wafer to be processed;

a gas source;

an inlet gas feed line having a first diameter and configured to receive a gas from the gas source;

a pair of symmetrical feeds, the symmetrical feeds configured to split a flow of the gas from the inlet gas feed line;

an expansion plenum having a second diameter greater than the first diameter and a plurality of outlet ports, wherein the expansion plenum receives gas from the pair of symmetrical feeds; and

a plurality of valves interposed between the expansion plenum and the reaction chamber, the plurality of valves configured to control flow of the gas from the plurality of outlet ports into the reaction chamber; and

wherein the plurality of valves maintains a substantially equalized pressure across the plurality of outlet ports.

2. The reaction system of claim 1, wherein the plurality of valves comprise proportioning or metering valves.

3. The reaction system of claim 2, wherein the plurality of valves controls a flow rate of the gas to a lower gas feed line.

4. The reaction system of claim 1, wherein the plurality of valves are configured to create restrictions to counteract a cascading flow of gas across the expansion plenum.

5. The reaction system of claim 1, wherein the inlet gas feed line comprises at least one of:

a gas line, bends, and fittings.

6. The reaction system of claim 1, further comprising an injection flange coupled to the plurality of outlet ports.

7. The reaction system of claim 1, wherein the expansion plenum is configured to receive the gas from opposite ends of the expansion plenum through the pair of symmetrical feeds.

8. The reaction system of claim 1, wherein the expansion plenum reduces a velocity of the gas when the gas fills the expansion plenum.

9. The reaction system of claim 1, wherein a substantially equal flow of gas across the wafer is achieved.

10. The reaction system of claim 1, further comprising a gas distribution block configured to receive the gas from the plurality of valves and provide the gas to the reaction chamber.

11. The reaction system of claim 10, wherein the gas distribution block further comprises:

a plurality of base gas metering valves;

a plurality of dopant gas metering valves; and

a monoblock.

12. The reaction system of claim 11, wherein the plurality of base gas metering valves and the plurality of dopant gas metering valves are mounted to the monoblock.

13. A gas manifold system, comprising:

an inlet gas feed line configured to receive a gas from a gas source;

a pair of symmetrical feeds, the symmetrical feeds having a first diameter and configured to split a flow of the gas from the inlet gas feed line;

an expansion plenum having a second diameter greater than the first diameter and a plurality of outlet ports, wherein the expansion plenum receives gas from the pair of symmetrical feeds; and

a plurality of valves interposed between the expansion plenum and the reaction chamber, the plurality of valves configured to control flow of the gas through the plurality of outlet ports of the expansion plenum; and

wherein the plurality of valves maintains a substantially equalized pressure across the plurality of outlet ports.

14. The gas manifold system of claim 13, wherein the plurality of valves comprise proportioning or metering valves.

15. The gas manifold system of claim 14, wherein the plurality of valves controls a flow rate of the gas to a lower gas feed line.

16. The gas manifold system of claim 13, wherein the plurality of valves are configured to create restrictions to counteract a cascading flow of gas across the expansion plenum.

17. The gas manifold system of claim 13, further comprising a gas distribution block configured to receive the gas from the plurality of valves and provide the gas to the reaction chamber.

18. The gas manifold system of claim 17, wherein the gas distribution block further comprises:

a plurality of base gas metering valves;

a plurality of dopant gas metering valves; and

a monoblock.