Patent ID: 7586608

Claim:
A method, comprising: directing a probe beam from an optical probe located above a surface of a wafer to the surface of the wafer; using an optical alignment structure on the wafer to direct a portion of the probe beam along a direction above the wafer; using the portion of the probe beam from the optical alignment structure as a guide to adjust a position of the optical probe relative to the optical alignment structure; using the optical alignment structure as a guide to move the wafer to place the optical probe at a first location above the wafer; using a positional relationship between the first location and a selected location on the wafer to move the wafer to position the optical probe from the first location to the selected location above the wafer; and using the optical probe to conduct an optical test on a component located at the selected location and eliminating the component from a subsequent processing step if the component fails a pre-determined test criteria of the optical test, wherein the optical alignment structure comprises an optical diffraction grating structure, wherein the optical diffraction grating structure provides a reflective surface for the incident probe beam.