Stage with two substrate buffer station
View Patent ↗A stage used, e.g., in semiconductor fabrication, includes a two substrate buffer station and a movable chuck. The buffer station, in one embodiment is fixed, i.e., non-movable relative to the stage. In another embodiment, the support elements of the buffer station may move in unison vertically or horizontally. In another embodiment, a pair of the support elements horizontally moves toward another pair of support elements to reduce the necessary horizontal motion of the chuck. For example, an unprocessed substrate is loaded onto the top supporting elements of the buffer station, while processed substrates are unloaded from the bottom supporting element of the buffer station. The movable chuck is used to remove the unprocessed substrates from the buffer station and to place the processed substrates on the buffer station.
1. A wafer measuring stage comprising:
a base;
a chuck movably coupled to said base, said chuck movable in at least a horizontal linear direction with respect to said base; and
a fixed buffer station having a plurality of support elements fixedly positioned above said base, said plurality of support elements including a first set of support elements for holding a substrate and a second set of support elements for holding a substrate, wherein said first set of support elements hold a substrate above a substrate held by the second set of substrates, said plurality of support elements having fixed horizontal and vertical positions relative to each other.
2. The stage of claim 1 , wherein said first set of support elements comprises four support elements and said second set of support elements comprises four support elements.
3. The stage of claim 1 , wherein said first set of support elements have a top surface for supporting a substrate, said top surface having an inclined portion for aligning a substrate on the top surface of said first set of support elements; and wherein said second set of support elements have a top surface for supporting a substrate, said top surface having an inclined portion for aligning a substrate on the top surface of said second set of support elements.
4. The stage of claim 1 , wherein said chuck is rotatable.
5. The stage of claim 1 , wherein said chuck is movable in two horizontal directions that are orthogonal to each other.
6. The stage of claim 1 , wherein said chuck is movable in a vertical direction and wherein said chuck loads and unloads substrates onto said plurality of support elements.
7. The stage of claim 6 , wherein said chuck unloads substrates from said first set of support elements and loads substrates onto said second set of substrates.
8. The stage of claim 6 , wherein said chuck is movable in a vertical linear direction between at least two of said first set of support elements and between at least two of said second set of support elements.
9. The stage of claim 6 , wherein:
the support elements in said first set of support elements are separated from each other so that they can support a substrate at the periphery of the substrate while allowing the chuck to raise between the first set of support elements without contacting said first set of support elements; and
the support elements in said second set of support elements are separated from each other so that they can support a substrate at the periphery of the substrate while allowing the chuck to rise between the second set of support elements without contacting said second set of support elements.
10. The stage of claim 6 , wherein said plurality of support elements having a fixed position relative to said base.
11. A wafer measuring stage comprising:
a base;
a chuck movably coupled to said base, said chuck movable in at least a horizontal linear direction with respect to said base; and
a fixed buffer station having a plurality of support elements fixedly positioned above said base, said plurality of support elements including a first set of support elements and a second set of support elements;
wherein the support elements in said first set of support elements are separated from each other so that they can support a substrate at the periphery of the substrate while the chuck moves in a horizontal linear direction between the support elements without contacting the support elements; and
wherein the support elements in said second set of support elements are separated from each other so that they can support a substrate at the periphery of the substrate while the chuck moves in a horizontal linear direction to pass between the second set of support elements without contacting with second set of support elements;
wherein said first set of support elements support a substrate in a position higher than the position that said second set of support elements support a substrate and said plurality of support elements have fixed vertical and horizontal positions relative to each other.
12. The stage of claim 11 , wherein said chuck moves in a vertical linear direction and wherein said chuck loads and unloads substrates onto said plurality of support elements.