System for resist defect measurement
First Claim
1. A test system for measuring and mapping pinhole defects in an insulator coating on a surface of a photoconductor substrate comprising:
- optical means for generating a minute spot of light substantially smaller than the area of said surface,means for scanning said spot of light over said surface,means for interposing an electrolyte containing a reducible solute between said surface and said spot of light,means for electrically biasing said substrate with respect to said electrolyte, andmeans for determining the magnitude and number of current flow variations across said coating and said electrolyte and for determining the scanning position of said spot of light, as respective measurements of the pinhole size, density and location in said coating.
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Accused Products
Abstract
A non-destructive test system for determining the number, size and location of pinhole defects in insulative coatings on a semiconductor substrate employing photocathodic current measurement at the semiconductor surface. This current is produced by contacting the coated semiconductor with an aqueous electrolyte, applying a small electrical bias with respect to a metal electrode, and scanning a small, focused light beam over the semiconductor surface. The frequency of current peaks produced is proportional to defect density. Current peaks provide data relative to defect size and location is correlated relative to scanning data to determine defect location.
30 Citations
20 Claims
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1. A test system for measuring and mapping pinhole defects in an insulator coating on a surface of a photoconductor substrate comprising:
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optical means for generating a minute spot of light substantially smaller than the area of said surface, means for scanning said spot of light over said surface, means for interposing an electrolyte containing a reducible solute between said surface and said spot of light, means for electrically biasing said substrate with respect to said electrolyte, and means for determining the magnitude and number of current flow variations across said coating and said electrolyte and for determining the scanning position of said spot of light, as respective measurements of the pinhole size, density and location in said coating. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for measuring and mapping pinhole defects in an insulator coating on a surface of a photoconductive substrate comprising the steps of:
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disposing an electrolyte between said surface and a source of light and electrically biasing said photoconductive substrate with respect to said electrolyte; scanning said surface with a minute spot of light substantially smaller than the area of said surface through an electrolyte in contact with and electrically biased with respect to said substrate, wherein said electrolyte contains a reducible solute, and measuring the magnitude and number of current flow variations and position of said spot of light to determine the pinhole size, density and location of such defects in said coating. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification