Resistively heated single wafer furnace

• US 6,303,906 B1
• Filed: 11/30/1999
• Issued: 10/16/2001
• Est. Priority Date: 11/30/1999
• Status: Expired due to Term

• Current Assignee: WaferMasters, Inc.
• Original Assignee: WaferMasters, Inc.
• Inventors: Yoo, Woo Sik
• Primary Examiner(s): Walberg, Teresa
• Assistant Examiner(s): Fuqua, Shawntina S.
• Application Number:
  US09/451,494
• Time in Patent Office: 686 Days
• Field of Search: 219/390, 219/405, 219/411, 118/724, 118/725, 118/50.1, 392/416, 392/418
• US Class Current: 219/390
• CPC Class Codes: H01L 21/67109 mainly by convection
• CPC Class Codes: H01L 21/67115 mainly by radiation

Abstract

A heating apparatus and method for isothermally distributing a temperature across the surface of a semiconductor device during processing. Specifically, a chamber is provided defining a cavity, which is configured to receive a single semiconductor wafer. A plurality of resistive heating elements are provided and advantageously arranged in the cavity. The heating elements are disposed across the chamber and are aligned in close proximity to one another so as to provide an even heating temperature distribution. In accordance with the present invention, the cavity is divided into heating zones. The resistive heating elements are each individually assigned to a zone and are independently controllable. By individually varying the amount of energy emanating from each resistive heating element, an isothermal temperature distribution may be generated across each zone.

Claims

1. An apparatus for rapidly and uniformly heating a wafer during processing, the apparatus comprising:

a process chamber having a top portion and a bottom portion, said process chamber defining a cavity configured to receive a wafer therein; and

a plurality of resistive heating elements positioned adjacent to said top portion and said bottom portion of said process chamber, each of said plurality of resistive heating elements being apportioned to one of a plurality of heating zones, a thermal energy output from each of said resistive heating elements capable of heating each of said heating zones to create a substantially isothermal environment throughout said cavity.

2. The apparatus of claim 1, wherein said process chamber is a tube made from material selected from the group consisting of quartz, Al₂O₃, and silicon carbide.

3. The apparatus of claim 1, wherein said process chamber is configured to be void of internal moving parts.

4. The apparatus of claim 1, wherein each of said resistive heating elements comprises a ceramic core wrapped with a wire comprising Al—

Ni—

Fe or NiCr alloy.

5. The apparatus of claim 1, wherein said process chamber has an aperture, said aperture being no greater than 40 mm in width.

6. The apparatus of claim 5, wherein an edge of said wafer is no less than 50 mm from said aperture when said wafer is placed within said cavity.

7. The apparatus of claim 1, wherein the thermal energy output of each of said resistive heating elements is controllable using a PID controller.

9. The apparatus of claim 1, wherein each of said plurality of heating zones comprises a temperature measuring device configured to send feedback information to a microprocessor.

10. The apparatus of claim 1, further comprising a heat diffusing material proximate to said plurality of heat resistive elements, said heat diffusing material causing said thermal energy output from each of said resistive heating elements to spread evenly through said cavity.

11. The apparatus of claim 10, wherein thermocouples are embedded within said heat diffusing material to measure the temperature of each of said heating zones.

12. The apparatus of claim 1, further comprising a means for quickly loading the wafer into said cavity.

8. An apparatus for rapidly and uniformly heating a wafer during processing, the apparatus comprising:

a process chamber defining a cavity configured to receive a wafer therein and further defining a plurality of heating zones; and

a plurality of resistive heating elements positioned proximate to said process chamber, each of said plurality of resistive heating elements being apportioned to one of said plurality of heating zones, a thermal energy output from each of said resistive heating elements capable of heating each of said zones to create a substantially isothermal environment throughout said cavity,

said plurality of heating zones comprises a first zone and a second zone, said first zone having a width greater than the diameter of said wafer.

13. A reactor for rapidly and uniformly heating a semiconductor wafer, the reactor comprising:

a chamber defining a cavity, said cavity further defining a plurality of heating zones said plurality of zones including a first zone having a width greater than a width of said wafer;

a plurality of resistive heating elements positioned proximate to said chamber, a portion of said plurality of resistive heating elements apportioned to each one of said plurality of heating zones;

a thermal energy output of each of said resistive heating elements heating said zones to provide a substantially isothermal temperature among each of said zones.

14. The reactor of claim 13, wherein each of said resistive heating elements comprises a ceramic core and a resistive wire comprising Al—

Ni—

Fe.

15. The reactor of claim 13, wherein said cavity has an aperture no greater than 50 mm in width.

16. The reactor of claim 13, wherein each of said zones comprises a temperature sensor configured to sense fluctuations in temperature.

17. The reactor of claim 13, further comprising a heat diffusing material positioned proximate to said plurality of heat resistive elements, said heat diffusing material causing said thermal energy output from each of said resistive heating elements to be dissipated evenly through said cavity.

18. A method for processing a semiconductor wafer, the method comprising:

apportioning a portion of a plurality of resistive heating elements over a top portion and a bottom portion of a process chamber to define a plurality of heating zones; and

generating a thermal output from said plurality of resistive heating elements to change the temperature of at least one of said heating zones in response to temperature fluctuations to provide a substantially isothermal environment over said semionductor wafer.