Wafer alignment mark scheme
First Claim
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1. A wafer alignment apparatus, comprising:
- a light source;
a light detection device; and
a rotation device rotates a wafer, the wafer including more than two wafer alignment marks in a surface of the wafer, each of the more than two wafer alignment marks including an identifiably different number of recesses in the surface of the wafer,wherein the light source provides light directed to the wafer, the light detection device detects identifiably different reflected light intensities from the identifiably different number of recess in the surface of the wafer to locate at least one wafer alignment mark of the more than two wafer alignment marks separated by a plurality of angles, and at least two of the angles are equal.
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Abstract
A wafer alignment apparatus includes a light source, a light detection device, and a rotation device configured to rotate a wafer. The light source is configured to provide light directed to the wafer. The light detection device is configured to detect reflected light intensity from the wafer to locate at least one wafer alignment mark of wafer alignment marks separated by a plurality of angles. At least two of those angles are equal.
9 Citations
21 Claims
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1. A wafer alignment apparatus, comprising:
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a light source; a light detection device; and a rotation device rotates a wafer, the wafer including more than two wafer alignment marks in a surface of the wafer, each of the more than two wafer alignment marks including an identifiably different number of recesses in the surface of the wafer, wherein the light source provides light directed to the wafer, the light detection device detects identifiably different reflected light intensities from the identifiably different number of recess in the surface of the wafer to locate at least one wafer alignment mark of the more than two wafer alignment marks separated by a plurality of angles, and at least two of the angles are equal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method, comprising:
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transmitting light from a light source to a wafer, the wafer including more than two wafer alignment marks in a surface of the wafer, each of the more than two wafer alignment marks including a different number of recesses in the surface of the wafer; rotating the wafer for a specified angle; detecting a plurality of identifiably different reflected lights from the different number of recesses by a light detection device; identifying at least one wafer alignment mark of the more than two wafer alignment marks based on the plurality of identifiably different reflected lights; and finding a position of the identified at least one wafer alignment mark of the more than two wafer alignment marks separated by a plurality of angles, and at least two of the angles are equal. - View Dependent Claims (12, 13, 14, 15, 16, 17, 20, 21)
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18. A wafer, comprising:
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more than two wafer alignment marks in a backside surface of the wafer, the backside surface of the wafer being opposite a frontside surface of the wafer, the frontside surface comprising integrated circuit structures, each of the more than two wafer alignment marks including an identifiably different number of recesses in the backside surface of the wafer, wherein recesses within a first one of the wafer alignment marks changes a light intensity reflected from the wafer a first amount in order to locate the at least one wafer alignment mark, wherein recesses within a second one of the wafer alignment marks changes a light intensity reflected from the wafer a second amount identifiably different from the first amount, the wafer alignment marks are separated by a plurality of angles, and at least two of the angles are equal. - View Dependent Claims (19)
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Specification