Method and apparatus for measuring cumulative defects
AssigneeAdvanced Micro Devices, Inc.
InventorChristopher L. Wooten
Life of this patent
Estimating the term…
Abstract
In one aspect of the present invention, a method and an apparatus are provided for determining a cumulative defect measure for a wafer lot. A wafer lot is selected for inspection. At least one wafer from the lot for inspection is selected. The wafer comprises a plurality of process layers and at least some of the process layers are selected for inspection for defects. The number, type, and kill ratio of the defects on each layer of the wafer selected are determined from inspection. A cumulative defect measurement for the wafer is determined based upon the number, type, and kill ratio of the defects on all inspected layers on the wafer. The cumulative defect measurement for the wafer is extrapolated to determine a quantified indication of a defectiveness of the selected wafer lot.
Claims43
A method for determining a cumulative defect measure for a wafer lot, comprising:
- selecting a wafer lot to be inspected;
- selecting at least one wafer from said wafer lot for inspection, said at least one wafer comprising a plurality of process layers, at least some of said process layers selected for inspection for defects;
- determining the number, type, and kill ratio of said defects on each process layer of said at least one wafer selected for inspection;
- determining a cumulative defect measurement for said at least one wafer based upon the number, type, and kill ratio of said defects on all inspected process layers on said at least one wafer;
- and
- extrapolating said cumulative defect measurement for said at least one wafer to determine a quantified indication of a defectiveness of said selected wafer lot.
An apparatus for determining a cumulative defect measure for a wafer lot, comprising:
- means for selecting a wafer lot to be inspected;
- means for selecting at least one wafer from said wafer lot for inspection, said at least one wafer comprising a plurality of process layers, at least some of said process layers selected for inspection for defects;
- means for determining the number, type, and kill ratio of said defects on each process layer of said at least one wafer selected for inspection;
- means for determining a cumulative defect measurement for said at least one wafer based upon the number, type, and kill ratio of said defects on all inspected process layers on said at least one wafer;
- and
- means for extrapolating said cumulative defect measurement for said at least one wafer to determine a quantified indication of a defectiveness of said selected wafer lot.
A computer readable program storage device encoded with instructions that, when executed by a computer, said instructions perform a method for measuring cumulative defects, said instructions comprising:
- instructions for selecting a wafer lot to be inspected;
- instructions for selecting at least one wafer from said wafer lot for inspection, said at least one wafer comprising a plurality of process layers, at least some of said process layers selected for inspection for defects;
- instructions for determining the number, type, and kill ratio of said defects on each process layer of said at least one wafer selected for inspection;
- instructions for determining a cumulative defect measurement for said at least one wafer based upon the number, type, and kill ratio of said defects on all inspected process layers on said at least one wafer;
- and
- instructions for extrapolating said cumulative defect measurement for said at least one wafer to determine a quantified indication of a defectiveness of said selected wafer lot.
Dependencies are inferred from the claim text.