Patent ID: 7505134

Claim:
A method of aligning an ellipsometer system which comprises: an ellipsometer source of a beam of electromagnetic radiation; a stage for supporting a sample and having means for effecting tip/tilt and translation thereof; a data detector of electromagnetic radiation; said method comprising: a) placing an alignment sample on said stage; b) generally orienting said ellipsometer source of a beam of electromagnetic radiation so that it directs a beam of electromagnetic radiation onto a first location of said alignment sample at an oblique angle, which beam then reflects from said alignment sample and enters said data detector so that it provides an output signal; performing steps: c1) while monitoring the output signal from said data detector causing said stage to effect translation of said alignment sample so that said beam is directed to a second location thereon at said oblique angle, reflects therefrom and enters said data detector, followed by adjusting the tip/tilt of said stage; c2) while monitoring the output signal from said data detector causing said stage to effect translation of said alignment sample so that said beam is directed to a third location thereon at said oblique angle, reflects therefrom and enters said data detector, followed by adjusting the tip/tilt of said stage, said third location being other than co-linear with said first and second locations; c3) while monitoring the output signal from said data detector causing said stage to effect translation of said alignment sample so that said beam is directed to a said first location thereon at said oblique angle, reflects therefrom and enters said data detector, followed by adjusting the tip/tilt of said stage; itteratively, in any functional order, until the output of the data detector is substantially the same in all said steps c1, c2 and c3; with the result being that the stage is oriented in tip/tilt so that no matter from what location on said alignment sample said beam is caused to reflect, the output from said data detector remains substantially the same; said method then optionally further comprising: d) while monitoring the data detector output signal moving the location and orientation thereof until said output signal therefrom is substantially maximized.