Claims
- 1. A method for inspecting a sample with a probe beam, said probe beam being focused to a spot onto the sample surface, said spot having a generally elliptical shape with a long and a short axis, with the properties of the probe beam being measured after reflection from the sample, the method comprising:
determining a proximity of an inspection spot on the sample surface to an edge of the sample; and positioning the sample with respect to the probe beam such that when the inspection spot is determined to be close to the edge of the sample, the probe beam spot falls on the inspection spot with the short axis being substantially perpendicular to the sample edge, the positioning of the sample including rotating the sample with respect to the probe beam in order to minimize an area of the sample which cannot be accurately inspected.
- 2. A method according to claim 1, further comprising:
determining a proximity of a subsequent inspection spot on the sample surface to an edge of the sample; and repositioning the sample with respect to the probe beam such that when the subsequent inspection spot is determined to be close to the edge of the sample, the probe beam spot falls on the subsequent inspection spot with the short axis being substantially perpendicular to the sample edge, the positioning of the sample including rotating the sample with respect to the probe beam.
- 3. A method according to claim 1, further comprising:
positioning the sample with respect to the probe beam such that when the inspection spot is not close to the edge of the sample, the positioning of the sample including translating the sample without rotation.
- 4. A method according to claim 1, wherein:
positioning the sample further includes translating the sample with respect to the probe beam.
- 5. A system for inspecting a sample, comprising:
a probe beam source capable of focusing a probe beam spot on the sample surface, said probe beam spot having a generally elliptical shape with a long and a short axis; and a movable stage for supporting the sample and adjusting the position of the sample with respect to the probe beam, the moveable stage being capable of both rotational and linear movement, the moveable stage capable of positioning the sample with respect to the probe beam such that when an inspection spot is determined to be close to the edge of the sample, the probe beam spot falls on the inspection spot with the short axis being substantially perpendicular to the sample edge, the positioning of the sample including rotating the sample with respect to the probe beam in order to minimize an area of the sample which cannot be accurately inspected.
- 6. A system according to claim 5, wherein:
the moveable stage is further capable of sequentially positioning the sample at a plurality of positions with respect to the probe beam to permit inspection of various additional inspection spots on the sample surface, and wherein when one of the additional inspection spots is close to the edge of the sample, rotationally positioning the sample so that the short axis of the elliptical probe beam spot is substantially perpendicular to the edge of the sample.
- 7. A system according to claim 5, wherein:
the probe beam source includes a rotating optics head capable of adjusting the shape of the beam spot on the sample surface.
PRIORITY INFORMATION
[0001] The present application is a continuation application of U.S. patent application Ser. No. 10/132,959 filed Apr. 26, 2002, STAGE ROTATION SYSTEM TO IMPROVE EDGE MEASUREMENTS, which claims the benefit of U.S. Provisional Application Serial No. 60/298,711 filed Jun. 15, 2001, STAGE ROTATION SYSTEM TO IMPROVE EDGE MEASUREMENTS, which is incorporated herein by reference.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60298711 |
Jun 2001 |
US |
Continuations (1)
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Number |
Date |
Country |
Parent |
10132959 |
Apr 2002 |
US |
Child |
10766125 |
Jan 2004 |
US |