Method for Inspecting Overlay Shift Defect during Semiconductor Manufacturing and Apparatus Thereof
AssigneeHermes Microvision, Inc.
InventorsWEI FANG, HONG XIAO, JACK JAU
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Abstract
A method for inspecting overlay shift defect during semiconductor manufacturing is disclosed herein and includes a step for providing a charged particle microscopic image of a sample, a step for identifying an inspection pattern measure in the charged particle microscopic image, a step for averaging the charged particle microscopic image by using the inspection pattern measure to form an averaged inspection pattern measure, a step for estimating an average width from the averaged inspection pattern measure, and a step for comparing the average width with a predefined threshold value to determine the presence of the overlay shift defect.
Claims26
A method for inspecting misalignment of photolithographic masks from a charged particle microscopic image, comprising:
- providing a charged particle microscopic image of a sample, said image representing at least two different patterns formed as part of said sample by using two successive photolithographic masks;
- identifying an inspection pattern measure from said image, said inspection pattern measure comprising a contact point of said two patterns;
- averaging said image taking said inspection pattern measure as a unit so as to reduce said image into an averaged said inspection pattern measure;
- estimating an average width of averaged said inspection pattern measure;
- and
- comparing said average width with a threshold value thereby determining the presence of misalignment of said successive photolithographic masks.
A charged particle beam inspection system, comprising:
- an image forming apparatus for forming a charged particle microscopic image of a sample, said image representing at least two different patterns formed as part of said sample by using two successive photolithographic masks;
- an image analysis apparatus coupled with said image forming apparatus for receiving said image therefrom, said image analysis apparatus at least comprising:
- a pattern identifying member for identifying an inspection pattern measure from said image, said inspection pattern measure comprising a contact point of said two patterns;
- an image averaging member for averaging said image taking said inspection pattern measure as a unit so as to reduce said image into an averaged said inspection pattern measure;
- an estimating member for estimating an average width of averaged said inspection pattern measure;
- and
- a defect determination member for comparing said average width with a threshold value thereby determining the presence of misalignment of said successive photolithographic masks.
A computing agent for inspecting misalignment of photolithographic masks from a charged particle microscopic image, comprising:
- an input module coupled with a charged particle beam microscope system for receiving therefrom a charged particle microscopic image of a sample,
- wherein said image is formed by said charged particle beam microscope system, and said image represents at least two patterns formed as part of said sample by using two successive photolithographic masks;
- a computing module coupled with said input module for receiving information of said image therefrom, said computing module at least comprising:
- a pattern identifying member for identifying an inspection pattern measure from said image, said inspection pattern measure comprising a contact point of two said patterns;
- an image averaging member for averaging said image taking said inspection pattern measure as a unit so as to reduce said image into an averaged said inspection pattern measure;
- an estimating member for estimating an average width of averaged said inspection pattern measure;
- and
- a defect determination member for comparing said average width with a threshold value thereby determining the presence of misalignment of said successive photolithographic masks.
A method for inspecting misalignment of photolithographic masks from a charged particle microscopic image, comprising:
- providing a charged particle microscopic image of a sample, said image representing at least two different patterns formed as part of said sample by using two successive photolithographic masks;
- identifying an inspection pattern period from said image, said inspection pattern period comprising a contact point of said two patterns;
- averaging said image taking said inspection pattern period as a unit so as to reduce said image into an averaged said inspection pattern period;
- estimating an average width of averaged said inspection pattern period;
- and
- comparing said average width with a threshold value thereby determining the presence of misalignment of said successive photolithographic masks.
Dependencies are inferred from the claim text.