Flaw inspection device and flaw inspection method

Patent metadata

Field	Value
Publication number	US-2019094155-A1
Application number	US-201616085890-A
Country	US
Kind code	A1
Filing date	Mar 30, 2016
Priority date	Mar 30, 2016
Publication date	Mar 28, 2019
Grant date	—

Abstract

The present invention aims at providing a defect inspection technique capable of setting parameters used for detecting a defect with a less burden to a user. A defect inspection device according to the present invention receives multiple reference values input by the user and calculates a defect extraction condition so as to optimize an evaluation value calculated with the use of the reference values, the number of actual reports, and the number of false reports (refer to FIG. 8 ).

First claim

1 . A defect inspection device for inspecting a defect of an inspection target, comprising:
an image generation unit that generates an exterior image of the inspection target; a feature amount calculation unit that calculates a feature amount of the exterior image; a storage unit that stores extraction condition data describing an initial value of a condition for extracting the defect of the inspection target; a defect determination unit that compares the feature amount with the condition to extract the defect of the inspection target; an output unit that outputs information representing the defect extracted by the defect determination unit; and an interface that receives a designation input for designating whether the defect extracted by the defect determination unit is an actual report or a false report, wherein the defect determination unit receives a plurality of reference values through the interface and calculates the condition under which an evaluation value calculated using the number of actual reports, the number of false reports, and the reference values becomes optimum for each of the reference values, the defect determination unit extracts the defect of the inspection target by using the condition calculated for each of the reference values, and the output unit outputs the condition calculated by the defect determination unit for each of the reference values for each of the reference values and outputs the defects extracted using the conditions calculated for each of the reference values and outputs information representing the extracted defect by using the condition calculated by the defect determination unit for each of the reference values.

2 . The defect inspection device according to claim 1 ,
wherein the defect determination unit calculates an actual report rate representing a rate of the number of actual reports to a total of the number of actual records and the number of false reports and calculates the evaluation value by using the actual report rate to extract the defect by using the actual report rate as the condition.

3 . The defect inspection device according to claim 2 ,
wherein the defect determination unit receives, as each of the reference values, a numerical value designating a weight of the actual report rate at the evaluation value, and calculates the evaluation value using the weight.

4 . The defect inspection device according to claim 1 ,
wherein the defect determination unit classifies the defect of the inspection target according to the feature amount and sets a weight coefficient for each classification of the defect, and the defect determination unit sets the weighting coefficient to increase the evaluation value more as the weight coefficient is larger for the classification belonging to the actual report, and decrease the evaluation value more as the weight coefficient is larger for the classification belonging to the false report.

5 . The defect inspection device according to claim 1 ,
wherein the defect determination unit receives a numerical value of a defect capture rate indicating a rate of the number of actual reports to the number of actual reports detected by using the initial value of the condition as the reference value, and the defect determination unit calculates the evaluation value by using the defect capture rate to extract the defect by using the defect capture rate as the condition.

6 . The defect inspection device according to claim 1 ,
wherein the defect determination unit receives a numerical value of a false report rate representing a rate of the number of false reports to a total of the number of actual reports and the number of false reports as the reference value, and the defect determination unit calculates the evaluation value by using the false report rate to extract the defect by using the false report rate as the condition.

7 . The defect inspection device according to claim 1 ,
wherein the defect determination unit receives a numerical value of a defect residual rate representing a rate of the number of false reports to the number of false reports detected by using the initial value of the condition as the reference value, and the defect determination unit calculates the evaluation value by using the defect residual rate to extract the defect by using the defect residual rate as the condition.

8 . The defect inspection device according to claim 1 , further comprising:
a plurality of detection systems that acquire a pixel value of the exterior image by imaging the inspection target and deliver the pixel value to the image generation unit; and a difference calculator that calculates a difference between the pixel value of the exterior image acquired by each of the detection systems and a pixel value of a reference image for each of the detection systems, wherein the defect determination unit obtains a linear sum of the differences respectively calculated by the difference calculator for one or more of the detection systems, and determines that a pixel corresponding to the difference is defective when the linear sum exceeds a first determination threshold.

9 . The defect inspection device according to claim 1 , further comprising:
a plurality of detection systems that acquire a pixel value of the exterior image by imaging the inspection target and deliver the pixel value to the image generation unit, and a difference calculator that calculates a difference between the pixel value of the exterior image acquired by each of the detection systems and a pixel value of a reference image for each of the detection systems, wherein the defect determination unit sets a second determination threshold that is the same as or different from each other for each of the detection systems in advance, and determines that a pixel corresponding to the difference is defective when the difference exceeds the second determination threshold for all of the detection systems.

10 . The defect inspection device according to claim 8 ,
wherein the defect determination unit sets a second determination threshold that is the same as or different from each other for each of the detection systems in advance, and the defect determination unit determines that the pixel corresponding to the difference is defective when the linear sum exceeds the first determination threshold and the difference exceeds the second determination threshold for all of the detection systems.

11 . The defect inspection device according to claim 1 ,
wherein the image generation unit generates the exterior image in each of partial areas of the inspection target and assigns an identifier of each of the partial areas to the exterior image, and the defect determination unit extracts the defect of the inspection target for each of the partial areas.

12 . The defect inspection device according to claim 1 ,
wherein the image generation unit generates the exterior image in each of partial areas of the inspection target and assigns an identifier of each of the partial areas to the exterior image, and the defect determination unit collectively extracts the defects of the inspection target for all of the partial areas and calculates the evaluation value by using the number of actual reports and the number of false reports for all of the partial areas to optimize the evaluation value for a total of all of the partial areas.

13 . The defect inspection device according to claim 1 , further comprising:
a reference image generation unit that generates a reference image by combining a plurality of the exterior images of the inspection target together; a difference calculation unit that calculates a difference betwee

Assignees

• Hitachi High Tech Corp

Inventors

• Honda Toshifumi
• Urano Takahiro
• Kobayashi Mamoru
• Hatano Hisashi
• Sakurai Hironori

Classifications

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H10P74/20

  characterised by the properties tested or measured, e.g. structural or electrical properties · CPC title

• G05B19/41875 Primary

  characterised by quality surveillance of production · CPC title

• G01N21/956 Primary

  Inspecting patterns on the surface of objects {(contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20)} · CPC title

• G01N21/9501

  Semiconductor wafers (manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20) · CPC title