Semiconductor wafer inspection using care area group-specific threshold settings for detecting defects
First Claim
1. A method comprising:
- receiving, by a processor from an optical inspection tool, optical images of multiple care areas on a semiconductor wafer; and
,analyzing, by the processor, the optical images to detect defects in the care areas, the analyzing comprising;
accessing an index of the care areas stored in memory, wherein the index indicates assignment of the care areas to different care area groups that are associated with different combinations of at least two of the following different design properties;
pattern density levels, percentages of edges oriented in an x-direction and a y-direction and pattern complexity levels and wherein the index further associates different threshold settings for detecting defects with the different care area groups, respectively; and
,using the index such that each care area in each specific care area group is analyzed based on a corresponding threshold setting associated in the index with the specific care area group.
5 Assignments
0 Petitions
Accused Products
Abstract
In the methods and systems, optical images of inspection care areas on a semiconductor wafer are acquired and analyzed to detect defects. However, during this analysis, the same threshold setting is not used for all inspection care areas. Instead, care areas are grouped into different care area groups, based on different design layouts and properties. Each group is associated with a corresponding threshold setting that is optimal for detecting defects in the inspection care areas belonging to that group. The assignment of the care areas to the different groups and the association of the different threshold settings with the different groups are noted in an index. This index is accessible during the analysis and used to ensure that each of the inspection care areas in a specific care area group is analyzed based on a corresponding threshold setting that is optimal for that specific care area group.
16 Citations
20 Claims
-
1. A method comprising:
-
receiving, by a processor from an optical inspection tool, optical images of multiple care areas on a semiconductor wafer; and
,analyzing, by the processor, the optical images to detect defects in the care areas, the analyzing comprising; accessing an index of the care areas stored in memory, wherein the index indicates assignment of the care areas to different care area groups that are associated with different combinations of at least two of the following different design properties;
pattern density levels, percentages of edges oriented in an x-direction and a y-direction and pattern complexity levels and wherein the index further associates different threshold settings for detecting defects with the different care area groups, respectively; and
,using the index such that each care area in each specific care area group is analyzed based on a corresponding threshold setting associated in the index with the specific care area group. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A system comprising:
-
a memory storing an index of care areas on a semiconductor wafer, wherein the index indicates assignment of the care areas to different care area groups that are associated with different combinations of at least two of the following different design properties;
pattern density levels, percentages of edges oriented in an x-direction and a y-direction and pattern complexity levels and wherein the index further associates different optimal sensitivity thresholds for detecting defects with the different care area groups; and
,an optical inspection tool; and a processor in communication with the memory and with the optical inspection tool, the processor receiving, from the optical inspection tool, optical images of the care areas, and the processor analyzing the optical images to detect defects in the care areas, the analyzing comprising accessing the index from the memory and using the index such that each care area in each specific care area group is analyzed based on a corresponding threshold setting associated in the index with the specific care area group. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
-
-
19. A computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions being executable by a processor to cause the processor to perform a method, the method comprising:
-
receiving, from an optical inspection tool, optical images of multiple care areas on a semiconductor wafer; and
,analyzing, by the processor, the optical images to detect defects in the care areas, the analyzing comprising; accessing an index of the care areas stored in memory, wherein the index indicates assignment of the care areas to different care area groups that are associated with different combinations of at least two of the following different design properties;
pattern density levels, percentages of edges oriented in an x-direction and a y-direction and pattern complexity levels and wherein the index further associates different threshold settings for detecting defects with the different care area groups, respectively; and
,using the index such that each care area in each specific care area group is analyzed based on a corresponding threshold setting associated in the index with the specific care area group. - View Dependent Claims (20)
-
Specification