Inspecting method and apparatus for repeated micro-miniature patterns

• US 6,661,912 B1
• Filed: 08/03/1998
• Issued: 12/09/2003
• Est. Priority Date: 08/03/1998
• Status: Expired due to Fees

• Current Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Tech Electronics Engineering Co., Ltd. (Hitachi, Ltd.)
• Inventors: Watanabe, Tetsuya, Sugimoto, Aritoshi, Taguchi, Junichi, Ikota, Masami, Inoue, Yuko, Shinke, Wakana
• Primary Examiner(s): AHMED, SAMIR ANWAR
• Application Number:
  US09/127,960
• Time in Patent Office: 1,954 Days
• Field of Search: 382/141, 382/145, 382/147, 382/148, 382/149, 348/87, 348/126, 356/237.3, 356/237.4, 356/237.5, 356/237.2, 250/559.04, 250/559.41, 250/559.42, 250/559.43, 250/559.44, 250/559.46, 250/559.45, 250/559.05, 250/559.06, 250/559.08, 250/559.39, 250/559.4, 438/16, 702/40, 702/82, 702/172, 702/459
• US Class Current: 382/145
• CPC Class Codes: G01N 21/95607 using a comparative method
• CPC Class Codes: G06T 2207/30148 Semiconductor; IC; Wafer
• CPC Class Codes: G06T 7/0004 Industrial image inspection
• CPC Class Codes: G06T 7/001 using an image reference approach

Abstract

An apparatus for inspecting foreign matter in repeated micro-miniature patterns formed upon a surface of an object to be inspected, comprising: an inspection light illuminating device for irradiating an inspection light directed upon the surface of the object to be inspected, on which the repeated micro-miniature patterns are formed; a scattered light detector for detecting scattered light of the inspection light being scattered upon the surface said object to be inspected; means for obtaining a first information related to a foreign matter attaching upon the surface of said object to be inspected, which is obtained on a basis of the detection of said scattered light by said scattered light detector; an illumination means for applying a bright field illumination upon the surface of the object to be inspected, on which the repeated micro-miniature patterns are formed; means for picking up the image of the foreign matter, under a bright field illumination by said illumination means; means for obtaining a second information related to said foreign matter, depending upon an image of said foreign matter, which is obtained on a basis of said picking up of the image by said image picking up means under the bright field illumination; and means for displaying said first information and said second information, both being related to said foreign matter, on a display screen thereof.

Claims

1. A method for inspecting foreign matters in or on repeated micro-miniature patterns formed upon a surface of an object to be inspected, comprising the following steps:

illuminating an inspection light of dark field directed obliquely upon the surface of the object to be inspected, on which the repeated micro-miniature patterns are formed, with a dark field inspection light illuminating device;

detecting scattered light of the dark field inspection light being scattered from the surface of said object to be inspected with at least a scattered light detector;

determining a coordinate position of a foreign matter upon the surface of said object to be inspected, on a basis of the detection of said scattered light in the above step, and thereby generating position information of the foreign matter;

illuminating an inspection light of bright field directed perpendicularly upon the surface of the object to be inspected, on which the repeated micro-miniature patterns are formed, with a bright field inspection light illumination device;

picking up an image of said foreign matter whose coordinate position is determined in the above step, under the bright field illumination by the bright field inspection illuminating device for illuminating the bright field inspection light in the above step, when the coordinate of the bright field inspection light is coincident with the coordinate of said foreign matter;

deciding said foreign matter at least one of size, shape, color and property thereof, depending upon an image of said foreign matter which is extracted on a basis of the image picked up in the above step;

processing information relating to the foreign matters based on the deciding in said deciding step; and

displaying said information relating to the foreign matters together with said coordinate position information of the foreign matter generated in said step of determining the coordinate position.

2. A method for inspecting foreign matters in or on repeated micro-miniature patterns, as defined in claim 1, further comprising a step of picking up an image of an another position of said repeated micro-miniature patterns of said object to be inspected, at a position corresponding to the coordinate position of said foreign matter which is determined by said detecting of the scattered light, under a bright field illumination by said illumination means, whereby the foreign matter image in said deciding step is extracted by comparing both said picked up images.

3. A method for inspecting foreign matters in or on repeated micro-miniature patterns, as defined in claim 1, further comprising a step of verifying appropriateness with respect to the determination made in said determining step of the coordinate position of said foreign matter upon the detecting of the scattered light, on a basis of the decision made on said foreign matter appearing in the image which is picked up in said picking up step.

4. A method for inspecting foreign matters in or on repeated micro-miniature patterns, as defined in claim 1, wherein the shape is determined in said deciding step, by use of the sizes of the image of said foreign matter which is obtained in said picking up step thereof.

5. A method for inspecting foreign matters in or on repeated micro-miniature patterns, as defined in claim 1, wherein the color is determined in said deciding step, by use of a color component and a gradation of the image of said foreign matter which is obtained in said picking up step thereof.

6. A method for inspecting foreign matters in or on repeated micro-miniature patterns, as defined in claim 1, wherein the property is determined in said deciding step, further by use of the scattered light from said detected foreign matter, which is detected with said scattered light detector.

7. An apparatus for inspecting foreign matters in or on repeated micro-miniature patterns formed upon a surface of an object to be inspected, comprising:

a dark field light illuminating device for illuminating a dark field inspection light directed obliquely upon the surface of the object to be inspected, on which the repeated micro-miniature patterns are formed;

a scattered light detector for detecting the scattered light of the dark field inspection light being scattered from the surface of said object to be inspected;

means for determining a coordinate position of a foreign matter upon the surface of said object to be inspected, on a basis of the detection of said scattered dark field light, and generating coordinate position information of the foreign matter;

an illumination means for applying a bright field illumination upon the surface of the object to be inspected, on which the repeated micro-miniature patterns are formed;

means for picking up an image of the foreign matter which is determined with the coordinate position thereof, under the bright field illumination by said illumination means, at the coordinate position corresponding to that which is determined through the scattered light detected by said scattered light detector under the dark field inspection light by said coordinate position determining means;

means for deciding the foreign matter at least one of size, shape, color and property thereof, depending upon an image of the foreign matter which is extracted on a basis of said picking up of the image obtained by said image picking up means;

means for processing information relating to the foreign matters based on the deciding of said means for deciding; and

a display for displaying the processed information relating to the foreign matters together with said information of coordinate position of the foreign matters, which is generated by said coordinate position determining means.

8. An apparatus for inspecting foreign matters, as defined in claim 7, wherein said image picking up means and said scattered light detecting means are constructed for a common use thereof.

9. An apparatus for inspecting foreign matters, as defined in claim 7, wherein a stage, in which said image picking up means picks up the image under the bright field illumination by said illumination means, is provided separately from a stage in which said scattered light detector detects the scattered light under the inspection light from said light illuminating device.

10. An apparatus for inspecting foreign matters, as defined in claim 7, further including:

means for obtaining a reference image by picking up the image of the micro-miniature pattern, under a bright field illumination, at an another coordinate position on the surface of said object to be inspected, which is corresponding to but different from the coordinate position which is determined by said determining means; and

means for obtaining an arithmetic processed image between said object image and said reference image, wherein said decision means decide a presence of a defect at the determined coordinate position on said object to be inspected, which is previously designated, on a basis of the arithmetic processed image obtained by said arithmetic processed image obtaining means.

11. An apparatus for inspecting foreign matters, as defined in claim 10, wherein said arithmetic processed image obtaining means obtain a difference image processed between said object image and said reference image.

12. An apparatus for inspecting foreign matters, as defined in claim 10, wherein said arithmetic processed image obtaining means obtain an addition image processed between said object image and said reference image.