Patent ID: 7247952

Claim:
An optical alignment target formed on a substrate, the target comprising: a planar central portion; and a contoured contrasting region that surrounds the planar central portion, the contoured contrasting region being formed from a first layer deposited on the substrate, a second layer deposited on the the first layer, and a third layer deposited on the second layer, the first layer having a topographic contour that forms patterned surface irregularities on an upper surface of the first layer, the second and third layers each having a topographic contour that generally mirrors the topographic contour of the first layer as a result of the second and third layers having been deposited on the first layer such that upper surfaces of the second and third layers have contours that follow contours of the upper surface of the first layer; wherein the optical alignment target can be readily detected from the contrast between the planar central portion and the contoured contrasting region that surrounds the planar central region.