Magnetic tunnel junction wafer adaptor used in magnetic annealing furnace and method of using the same
Semiconductor substrate adaptor configured to adapt a substrate of a first dimension to a second dimension, such that the substrate can be properly supported by a supporting mechanism (e.g., a wafer cassette) customized for substrates of the second dimension. The substrate adaptor may be made of quartz. The combination of the substrate adaptor and a substrate fitting therein causes no perturbation in various aspects of a semiconductor process. Therefore, the substrate adaptor conveniently enables a substrate of the first dimension to be processed in the same processing equipment and conditions as a substrate of the second dimension. A vertical substrate adaptor may have a semicircular body with a semicircular cutout for accommodating a wafer and can support a wafer vertically. A horizontal substrate adaptor may have a circular body with a circular cutout for accommodating an entire wafer and supporting the wafer horizontally.
1. A planar wafer adaptor comprising:
a planar body;
a first cutout from the planar body;
a first boundary of said planar body having a perimeter contour substantially equivalent to a portion of a semiconductor wafer of a first dimension;
a second boundary along said first cutout and having a perimeter contour substantially equivalent to a portion of a semiconductor wafer of a second dimension; and
a slot disposed along said second boundary and configured to receive an edge of said semiconductor wafer of said second dimension and configured to vertically orient said semiconductor wafer of said second dimension when said planar body is vertically oriented.
2. The planar wafer adaptor of claim 1 , wherein said planar body comprises quartz.
3. The planar wafer adaptor of claim 1 , wherein said first boundary comprises a notch.
4. The planar wafer adaptor of claim 1 , wherein said first boundary is configured to fit in a cassette configured to accommodate semiconductor wafers of said first dimension.
5. The planar wafer adaptor of claim 1 , wherein said first boundary substantially defines a semicircle.
6. The planar wafer adaptor of claim 1 , wherein said first boundary defines an arc less than a semicircle.
7. The planar wafer adaptor of claim 1 , wherein said first cutout is substantially a semicircle.
8. The planar wafer adaptor of claim 7 , wherein said second boundary comprises a flat cut.
9. The planar wafer adaptor of claim 1 , wherein said first cutout is a minor segment of a circle.
10. The planar wafer adaptor of claim 1 , wherein a semiconductor wafer of said first dimension is 300 mm in diameter.
11. The planar wafer adaptor of claim 1 , wherein a semiconductor wafer of said second dimension is one of 50 mm, 100 mm and 200 mm in diameter.
12. The planar wafer adaptor of claim 1 , wherein said slot is 3 mm in depth.
13. The planar wafer adaptor of claim 1 further comprising:
a second cutout from the planar body;
a third boundary along said second cutout and having a perimeter contour substantially equivalent to a portion of a semiconductor wafer of said second dimension; and
a slot disposed along said third boundary and configured to receive an edge of a semiconductor wafer of said second dimension.
14. The planar wafer adaptor of claim 1 further comprising:
a second cutout from the planar body;
a third boundary along said second cutout and having a perimeter contour substantially equivalent to a portion of a semiconductor wafer of a third dimension; and
a slot disposed along said third boundary and configured to receive an edge of said semiconductor wafer of said third dimension.
15. The planar wafer adaptor of claim 1 , wherein said second dimension is smaller than said first dimension and wherein said planar body has a thermal mass that is substantially equal to a thermal mass of a semiconductor wafer of said first dimension minus a thermal mass of said semiconductor wafer of said second dimension.
16. A planar wafer holder comprising:
a planar body having a perimeter contour substantially equivalent to a portion of a semiconductor wafer of a first dimension;
a first cutout from the planar body and having a perimeter contour substantially equivalent to a portion of a semiconductor wafer of a second dimension that is smaller than said first dimension; and
a slot disposed along said first cutout and configured to: receive an edge of said semiconductor wafer of said second dimension; and accommodate said semiconductor wafer of said second dimension in a cassette configured to contain a semiconductor wafer of said first dimension.
17. The planar wafer holder of claim 16 , wherein said planar body is made of quartz, and wherein further said slot is further configured to vertically orient said semiconductor wafer of said second dimension when said planar body is also vertically oriented.
18. The planar wafer holder of claim 16 , wherein said planar body is substantially a semicircle of said first dimension and wherein said first cutout is substantially a semicircle of said second dimension, and wherein said planar body has a mass equivalent to a wafer of said first dimension minus a mass of said wafer of said second dimension.
19. The planar wafer holder of claim 16 , wherein a semiconductor wafer of said first dimension is 300 mm in diameter, and wherein said semiconductor wafer of said second dimension is one of 50 mm, 100 mm, 150 mm, and 200 mm in diameter.
20. The planar wafer holder of claim 16 , wherein said planar body comprises a notch and wherein further said first cutout comprises a flat cut.
21. The planar wafer holder of claim 16 , wherein a weight of said planar wafer holder in combination with said semiconductor wafer of said second dimension is substantially equal to a weight of a semiconductor wafer of said first dimension.
22. The planar wafer holder of claim 16 , wherein said cassette is configured to accommodate a plurality of semiconductor wafers of said first dimension.
23. A method of processing semiconductor wafers in a processing apparatus, said method comprising:
calibrating a heating system of said processing apparatus based on a thermal load of a semiconductor wafer of a first dimension;
providing a semiconductor wafer of a second dimension that is smaller than said first dimension;
providing a substrate adaptor configured to vertically support said semiconductor wafer of said second dimension,
coupling said semiconductor wafer of said second dimension with said substrate adaptor;
loading said semiconductor wafer of said second dimension with said substrate adaptor into a cassette configured to contain a semiconductor wafer of said first dimension;
loading said cassette containing said semiconductor wafer of said second dimension with said substrate adaptor to said processing apparatus; and
processing said semiconductor wafer of said second dimension in said processing apparatus in a vertical orientation.
24. The method of claim 22 , wherein said planar body has a thermal mass that is substantially equal to a thermal mass of a semiconductor wafer of said first dimension minus a thermal mass of said semiconductor wafer of said second dimension.
25. The method of claim 23 , wherein said substrate adaptor has a thermal mass that is substantially equal to a thermal mass of a semiconductor wafer of said first dimension minus a thermal mass of said semiconductor wafer of said second dimension.
26. The method of claim 23 , wherein said substrate adaptor comprises:
a planar body having a perimeter contour substantially equivalent to a portion of a semiconductor wafer of said first dimension;
a first cutout from the planar body and having a perimeter contour substantially equivalent to a portion of said semiconductor wafer of said second dimension; and
a slot disposed along said first cutout, and wherein said coupling comprises inserting an edge of said semiconductor wafer of said second dimension to said slot.