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US 6,611,325 B1Granted
Enhanced defect detection using surface scanning inspection tools
AssigneeSEH America, Inc.
InventorDouglas A. Clark
Life of this patent
Estimating the term…
Abstract
A surface scanning inspection system that uses a laser to scan the surface of a wafer for defects. The wafers are pre-aligned at a specified angle prior to the scan. This enables maximum light scattered off stacking fault defects, to be directed into a collector, enhancing the abilities of the system to classify the defect from other type of defects.
Claims27
A scanning system for use with wafers, comprising:
- a scanner that emits light towards the wafer;
- a scattered light collector that receives scattered light scattered from the wafer;
- and
- an aligning device that aligns the wafer at a specified orientation prior to the wafer receiving the light emitted from the scanner so as to affect an amount of scattered light receivable by the scattered light collector, wherein the wafer defines a trailing end, a notch and an upper surface that intersects the light emitted from the scanner, the wafer being rotated at least one of 34, 35, 36, 44, 45 and 46 degrees relative to a plane perpendicular to the upper surface of the wafer, such that the notch is spaced from the trailing end of the wafer when the wafer is transported through the scanner by a wafer transporter.
1 more element
A method of scanning a wafer, comprising the steps of:
- emitting light towards the wafer;
- receiving scattered light scattered from the wafer;
- and
- aligning the wafer at a specified orientation, prior to receiving the emitted light, so as to affect an amount of scattered light receivable by the scattered light collector, wherein the wafer defines a trailing end, a notch and an upper surface that intersects the light emitted from a scanner, the wafer being rotated at least one of 34, 35, 36, 44, 45 and 46 degrees relative to a plane perpendicular to the upper surface of the wafer, such that the notch is spaced from the trailing end of the wafer when the wafer is transported through the scanner by a wafer transporter.
1 more element
A scanning system for use with wafers, comprising:
- means for emitting light towards the wafer;
- means for receiving scattered light scattered from the wafer;
- and
- means for aligning the wafer at a specified orientation, prior to receiving the emitted light, so as to affect an amount of scattered light receivable by the means for receiving, wherein the wafer defines a trailing end, a notch and an upper surface that intersects the light emitted from a scanner, the wafer being rotated at least one of 34, 35, 36, 44, 45 and 46 degrees relative to a plane perpendicular to the upper surface of the wafer, such that the notch is spaced from the trailing end of the wafer when the wafer is transported through the scanner by a wafer transporter.
1 more element
Dependencies are inferred from the claim text.