Method, apparatus and program for processing a contrast picture image of a semiconductor element

• US 8,774,492 B2
• Filed: 09/20/2011
• Issued: 07/08/2014
• Est. Priority Date: 09/24/2010
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Nikaido, Masafumi
• Primary Examiner(s): Fitzpatrick, Atiba O
• Assistant Examiner(s): JAMES, THOMAS AIDEN
• Application Number:
  US13/237,472
• Publication Number:
  US 20120076394A1
• Time in Patent Office: 1,022 Days
• Field of Search: None
• US Class Current: 382/145
• CPC Class Codes: G06T 2207/10061 from scanning electron microscope
• CPC Class Codes: G06T 2207/20192 Edge enhancement; Edge preservation
• CPC Class Codes: G06T 2207/30148 Semiconductor; IC; Wafer
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: G06T 5/92 based on global image properties
• CPC Class Codes: G06T 7/0004 Industrial image inspection
• CPC Class Codes: G06T 7/11 Region-based segmentation
• CPC Class Codes: G06T 7/136 involving thresholding
• CPC Class Codes: H04N 1/58 Edge or detail enhancement; Noise or error suppression, e.g. colour misregistration correction H04N1/62 takes precedence

Abstract

A method for processing a contrast picture image of a semiconductor element. The method comprises; a color grade number reducing processing that automatically reduces number of color grades of the contrast picture image of the semiconductor element, obtained from a device for analysis, in keeping with the contrast of the contrast picture image; an interconnect contrast extraction processing that classifies pixels contained in the contrast picture image, whose number of color grades has been reduced, in accordance with a preset contrast threshold value as reference, to extract an interconnect pattern fractionated into a plurality of number of contrasts; and a shift processing that removes noise contained in a contour portion of the interconnect pattern by shifting the contour portion; whereby an interconnect pattern contained in the contrast image of the semiconductor element obtained from the device for analysis is fractionated into a plurality of preset contrasts to be extracted.

Claims

1. A method for processing a contrast picture image of a semiconductor element comprising:

a color grade number reducing processing that automatically reduces a number of color grades of said contrast picture image of the semiconductor element, obtained from a device for analysis, in keeping with the contrast of said contrast picture image;

an interconnect contrast extraction processing that classifies pixels contained in said contrast picture image, whose number of color grades has been reduced, in accordance with a preset contrast threshold value as reference, to extract an interconnect pattern fractionated into a plurality of number of contrasts, wherein said interconnect contrast extraction processing includes;

(1) turning said contrast image, whose number of color grades has been reduced, into a bi-level image, using a preset first contrast threshold value as reference, to extract an interconnect pattern of a first contrast level; and

(2) turning a contrast image, obtained after excluding the interconnect pattern already extracted in the color-grade-number-reduced contrast image, into another bi-level image, using a K'"'"'th contrast threshold value out of an N-number of the contrast threshold values as reference, where N is the number of said contrast threshold values and is an integer not less than 2, to extract an interconnect pattern of the K'"'"'th contrast level;

the sequence of operations of turning the contrast images into the bi-level images and extracting the interconnect patterns being repeated as the value of K is incremented by 1 from K=2 until K=N each time, where K is an integer;

whereby the interconnect patterns fractionated into N levels of contrast is extracted; and

a shift processing that removes noise contained in a contour portion of said interconnect pattern by shifting said contour portion;

whereby

an interconnect pattern contained in said contrast image of said semiconductor element obtained from said device for analysis is fractionated into a plurality of preset contrasts to be extracted.

2. The method for processing a contrast picture image of a semiconductor element according to claim 1, wherein

in case the interconnect pattern fractionated into desired contrast levels has not been obtained, extraction of the interconnect pattern based on the contrast level is re-done as the threshold value is changed to a new value.

3. The method for processing a contrast picture image of a semiconductor element according to claim 1, wherein,

picture image processing is carried out as a picture image at each of a plurality of optional processing stages is displayed and verified.

4. The method for processing a contrast picture image of a semiconductor element according to claim 1, wherein,

said color grade number reducing processing is carried out without exterior criterion using a data clustering method.

5. The method for processing a contrast picture image of a semiconductor element according to claim 1, further comprising:

a noise removing processing that reduces noise contained in the contrast image before said color grade number reducing processing.

6. The method for processing a contrast picture image of a semiconductor element according to claim 5, wherein

said noise reducing processing is carried out using a noise filter selected out of a plurality of noise filters.

7. The method for processing a contrast picture image of a semiconductor element according to claim 5, wherein

said noise removing processing is carried out by selecting any number of filters in an arbitrary order at any number of times from the group consisting of a bilateral filter, a median filter and a contraction/expansion filter, parameters of which may arbitrarily be set.

9. The device for processing a contrast picture image of a semiconductor element according to claim 7, further comprising:

a setting unit that allows a setting picture image screen to be displayed;

said setting picture image screen being applied in setting said contrast threshold value used by said interconnect contrast extraction unit;

said setting picture image screen allowing an operator to input changes of parameters for picture image processing including said contrast threshold value;

said picture image data outputting unit being so designed that picture image data being processed in any stage until an interconnect pattern image freed of noise in a contour portion of the input contrast image of said semiconductor element is obtained by said shift unit as display data for confirmation by said operator.

13. The device for processing a contrast picture image of a semiconductor element according to claim 9, further comprising:

a noise removing unit that removes the noise contained in the input contrast image of the semiconductor element;

said noise removing unit including a plurality of noise filters of different sorts including a bilateral filter, a median filter and a contraction/expansion filter;

said setting unit being designed so as to select a noise filter of an any sort, out of said plurality of sorts of noise filters, in a desired sequence at a desired number of times, as a desired parameter is set in the selected noise filter, in order to effect noise removal;

said color grade number reducing unit receiving a contrast image freed of noise by said noise removing unit.

8. A device for processing a contrast picture image of a semiconductor element, comprising:

a color grade number reducing unit that receives a contrast image of the semiconductor element obtained from a device for analysis, automatically reduces the number of color grades of the input contrast picture image based on contrast distribution of the input contrast image and that outputs a contrast image having a reduced number of color grades;

an interconnect contrast extraction unit that receives said contrast image having the reduced number of color grades, classifies pixels contained in said contrast picture image, whose number of color grades has been reduced, in accordance with a preset contrast threshold value as reference, to extract an interconnect pattern fractionated into a plurality of contrasts, wherein,

with the number of said contrast threshold values being N, N being an integer not less than 2,

said interconnect contrast extraction unit executes processing of turning said contrast image, whose number of color grades has been reduced, into a bi-level image, with the use of a preset first one of said contrast threshold values as reference, to extract an interconnect pattern of a first contrast; and

processing of turning, in continuation to extraction of the interconnect pattern of the first contrast, another contrast image, obtained after excluding the interconnect pattern already extracted in the color-grade-number-reduced contrast image, into a hi-level image, using a K'"'"'th contrast threshold value out of said N-number of the contrast threshold values as reference, to extract an interconnect pattern of the K'"'"'th contrast level;

the sequence of operations of turning into the bi-level images and interconnect pattern extraction being repeated as the value of K is incremented by 1 from K=2 until K=N each time, where K is an integer;

whereby the interconnect patterns fractionated into N levels of contrast is extracted;

a shift unit that inputs the interconnect pattern image extracted by said interconnect contrast extraction unit and that removes noise contained in a contour portion of said interconnect pattern by shifting said contour portion; and

a picture image data outputting unit that outputs an interconnect pattern image, freed of noise of said contour portion by said shift unit, as picture image data.

10. The device for processing a contrast picture image of a semiconductor element according to claim 8, wherein,

said color grade number reducing unit reduces the number of color grades without exterior criterion using a data clustering method.

11. The device for processing a contrast picture image of a semiconductor element according to claim 8, further comprising:

a noise removing unit that removes noise contained in the input contrast image of the semiconductor element;

said color grade number reducing unit receiving the contrast image freed the noise by said noise removing unit.

12. The device for processing a contrast picture image of a semiconductor element according to claim 11, wherein,

said noise removing unit includes a plurality of noise filters of different sorts and is configured for removing the noise using one or more noise filters selected out of said plurality of sorts of noise filters.

14. A non-transitory computer-readable medium encoded with a computer program for processing a contrast picture image of a semiconductor element, wherein

the program allows a computer to execute a color grade number reducing processing of inputting a contrast image of said semiconductor element, obtained from a device for analysis, automatically reducing the number of color grades of said input contrast image based on the contrast distribution thereof and outputting a contrast image whose number of color grades has been reduced;

an interconnect contrast extraction processing of receiving a contrast image, whose number of color grades has been reduced, classifying pixels contained in said contrast image, whose number of color grades has been reduced, in accordance with a preset contrast threshold value, and extracting an interconnect pattern image fractionated into a plurality of contrasts, wherein,

with the number of said contrast threshold values being N, N being an integer not less than 2,

said interconnect contrast extraction unit initially executes a processing of turning said contrast image, whose number of color grades has been reduced, into a bi-level image, using a preset first one of said contrast thresh values as reference, to extract an interconnect pattern of a first contrast;

said interconnect contrast extraction unit executing a processing of turning, in continuation to extraction of the interconnect pattern of the first contrast, another contrast image, obtained after excluding the interconnect pattern already extracted in the color-grade-number-reduced contrast image, into a bi-level image, using a K'"'"'th contrast threshold value out of said N-number of the contrast threshold values as reference, to extract an interconnect pattern of the K'"'"'th contrast level;

the sequence of operations of turning into the bi-level images and interconnect pattern extraction being repeated as the value of K is incremented by 1 from K=2 until K=N each time, where K is an integer;

whereby the interconnect patterns fractionated into N levels of contrast is extracted;

a shift processing of receiving the interconnect pattern image extracted by said interconnect contrast extraction processing and removing noise of a contour portion of said interconnect included in said interconnect pattern image by shifting said contour portion; and

a picture image data outputting processing of outputting an interconnect pattern image, freed of the noise in said contour portion by said shift processing, as picture image data.

15. The non transitory computer-readable medium encoded with the program for processing a contrast picture image of a semiconductor element according to claim 14 wherein,

the program further includes a setting processing that allows a setting picture image screen to be displayed;

said setting picture image screen being applied in setting said contrast threshold value used by said interconnect contrast extraction unit;

said setting picture image screen allowing an operator to input changes of parameters for picture image processing including said contrast threshold value;

said picture image data outputting processing including the processing of outputting picture image data being processed in any stage until an interconnect pattern image freed of noise in a contour portion of the input contrast image of said semiconductor element is obtained by said shift unit as display data for confirmation by said operator.

16. The non-transitory computer-readable medium encoded with the program for processing a contrast picture image of a semiconductor element according to claim 14, further comprising:

a noise removing processing of removing the noise contained in said input contrast image of said semiconductor element;

said color grade number reducing operation receiving a contrast image freed of noise by said noise removing processing.

17. The non-transitory computer-readable medium encoded with the program for processing a contrast picture image of a semiconductor element according to claim 15, further comprising:

a noise removing processing of removing the noise contained in the input contrast image of said semiconductor element;

said noise removing processing selecting any sort of the noise filter out of a plurality of sorts of noise filters, including a bilateral filter, a median filter and a contraction/expansion filter, with an arbitrary parameter, in a desired order at a desired number of times, in order to effect noise removal;

said setting processing displaying a picture image that allows setting the sorts, order of use and the number of times of use of the noise filters and filter parameters;

said noise removing processing being carried out based on input data;

said color grade number reducing processing receiving a contrast image freed of noise by said noise removing processing.