High rate magnetic annealing system and method of operating

Patent metadata

Field	Value
Publication number	US-2016177412-A1
Application number	US-201514752271-A
Country	US
Kind code	A1
Filing date	Jun 26, 2015
Priority date	Dec 17, 2014
Publication date	Jun 23, 2016
Grant date	—

Abstract

An annealing system and method of operating is described. The annealing system includes a furnace having a vacuum chamber wall that defines a processing space into which a plurality of workpieces may be translated and subjected to thermal and magnetic processing, wherein the furnace further includes a heating element assembly having at least one heating element located radially inward from the vacuum chamber wall and immersed within an outer region of the processing space, and wherein the heating element is composed of a non-metallic, anti-magnetic material. The annealing system further includes a magnet system arranged outside the vacuum chamber wall of the furnace, and configured to generate a magnetic field within the processing space.

First claim

1 . A magnetic annealing system, comprising:
a furnace comprising a vacuum chamber wall that defines a processing space into which a plurality of workpieces may be translated and subjected to thermal and magnetic processing, the furnace further comprising a heating element assembly including at least one heating element located radially inward from the vacuum chamber wall and immersed within an outer region of the processing space, wherein the heating element is composed of a non-metallic, anti-magnetic material; and a magnet system arranged outside the vacuum chamber wall of the furnace, and configured to generate a magnetic field within the processing space.

2 . The system of claim 1 , wherein the heating element is composed primarily of carbon (C)

3 . The system of claim 1 , wherein the furnace is oriented in a horizontal configuration such that workpieces are translated horizontally into and out of the furnace, or wherein the furnace is oriented in a vertical configuration such that workpieces are translated vertically into and out of the furnace.

4 . The system of claim 1 , further comprising:
a workpiece boat for carrying the plurality of workpieces; and a boat loader operably configured to translate the workpiece boat and position the workpieces within the processing space.

5 . The system of claim 4 , further comprising:
a workpiece boat turntable arranged adjacent the vertical furnace, and configured to support at least two workpiece boats and index the at least two workpiece boats between a process position and a load/unload position, the workpiece boat turntable having an opening to permit the boat loader to engage and translate the workpiece boat into and out of the furnace.

6 . The system of claim 1 , wherein the furnace excludes a process tube surrounding the process space and the at least one heating element is disposed in vacuum during processing.

7 . The system of claim 1 , wherein the heating element comprises a carbon element sheathed within a protective casing.

8 . The system of claim 7 , wherein the protective casing is quartz.

9 . The system of claim 1 , wherein the vacuum chamber wall is composed of stainless steel, and at least a portion of an inner surface of the vacuum chamber wall has a reflectance that is equal to or greater than 50%.

10 . The system of claim 1 , further comprising:
a controller operably coupled to the furnace and the magnet system, and programmably configured to operate a power supply coupled to the at least one heating element.

11 . The system of claim 10 , wherein the controller programmably operates the power supply to achieve workpiece heating rates ranging from about 10° C. per minute to about 100° C. per minute.

12 . The system of claim 10 , wherein the controller programmably operates the power supply to achieve workpiece cooling rates ranging from about 5° C. per minute to about 20° C. per minute.

13 . The system of claim 1 , wherein the magnet system includes an electromagnet or a permanent magnet.

14 . The system of claim 1 , wherein the magnet system includes a solenoid magnet or a Helmholtz magnet.

15 . The system of claim 1 , wherein the magnet system includes a superconducting magnet.

16 . The system of claim 1 , wherein the magnet system generates a magnetic field within the processing space having a magnetic field strength ranging up to 10 Tesla.

17 . A method of operating a magnetic annealing system, comprising:
loading a plurality of workpieces into a first workpiece boat; translating the first workpiece boat into a processing space of a furnace using a boat loader, the furnace comprising a heating element assembly including at least one heating element surrounding the first workpiece boat, wherein the heating element is composed of a non-metallic, anti-magnetic material; elevating a temperature of the plurality of workpieces by coupling power to the heating element assembly; generating a magnetic field within the processing space using a magnet system arranged outside the furnace.

18 . The method of claim 17 , wherein the heating element is composed primarily of carbon (C).

19 . The method of claim 17 , further comprising:
immersing the at least one heating element within vacuum and in direct line-of-sight with the plurality of workpieces in the processing space.

20 . The method of claim 17 , further comprising:
heating the plurality of workpieces at a rate ranging from about 10° C. per minute to about 100° C. per minute; and cooling the plurality of workpieces at a rate ranging from about 5° C. per minute to about 20° C. per minute.

Assignees

• Tokyo Electron Ltd

Inventors

• Ishii Toru
• Yamazaki Mitsuru

Classifications

• H01F41/304

  using temporary decoupling, e.g. involving blocking, Néel or Curie temperature transitions by heat treatment in presence/absence of a magnetic field · CPC title

• C21D9/00

  Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor · CPC title

• C21D9/0006 Primary

  Details, accessories not peculiar to any of the following furnaces (control devices C21D11/00) · CPC title

• C21D1/26

  Methods of annealing · CPC title

• H01F41/02

  for manufacturing cores, coils, or magnets (H01F41/14 takes precedence; for dynamo-electric machines H02K15/00) · CPC title