CPC H01L 21/681 (2013.01) [G01B 11/24 (2013.01); H01L 21/6831 (2013.01); H01L 21/68721 (2013.01); G01B 2210/56 (2013.01)] | 18 Claims |
1. An apparatus comprising
a substrate holder to secure a substrate;
a first actuator to rotate the substrate holder about a first axis;
a second actuator to move the substrate holder linearly along a second axis;
a first sensor to generate one or more first measurements or images of a first plurality of target positions on the substrate;
a second sensor to generate one or more second measurements of a second plurality of target positions on the substrate; and
a processing device to:
determine, based on the one or more first measurements or images of the first plurality of target positions, an estimate of a position of the substrate on the substrate holder;
cause the first actuator to rotate the substrate holder about the first axis for measurement of a target position of the second plurality of target positions, wherein the rotation causes an offset between a field of view of the second sensor and the target position on the substrate due to the substrate not being centered on the substrate holder;
cause the second actuator to move the substrate holder linearly along the second axis to correct the offset; and
determine a profile across a surface of the substrate based on the one or more second measurements of the second plurality of target positions generated by the second sensor.
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