×

Method and apparatus for processing pattern image data by SEM

  • US 5,887,080 A
  • Filed: 01/27/1995
  • Issued: 03/23/1999
  • Est. Priority Date: 01/28/1994
  • Status: Expired due to Fees
First Claim
Patent Images

1. An apparatus for processing a pattern image, comprising:

  • analog-digital conversion means for converting into digital data from analog image data including a repetitive pattern such as contact holes which are made through a semiconductor substrate and which are obtained by a scanning electron microscope (SEM);

    spatial filtering processing means for performing a spatial filtering processing with respect to said digital image data of the contact holes by a predetermined filter coefficient so as to obtain smoothed spatial filtering image data about each of said contact holes;

    histogram processing means for classifying a histogram of pixel data constituting said smoothed spatial filtering image data corresponding to a gray scale level degree;

    threshold value set means for detecting and setting a slice of a threshold value as a gray level value;

    three-valued processing means for performing a three-valued processing with respect to said image data by using said slice level of the threshold value set by said threshold set means so as to obtain three-valued image data of a pattern surface region, a pattern taper region and a pattern bottom region;

    noise reduction means for reducing noises and pseudo patterns in said three-valued image data processed by said three-valued processing means by means of a repetition of a contraction and expansion;

    pattern area calculation means for calculating a respective area of a pattern one by one by means of a selection by a labeling processing, said pattern which is shown by a specified density and included in said repetitive pattern included in said three-valued image data in which said noises and said pseudo pattern are reduced by said noise reduction means;

    reference image storage means for storing as a reference area value an area of a reference image in one pattern constituting said repetitive pattern as a detected object; and

    pattern comparison and detection means for detecting a pattern having a most approximate area value within an entire area of a plurality of contact holes as patterns after comparing said area value of each pattern obtained by said pattern area calculation means with said reference area value of said reference image stored in said reference image storage means.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×