Method of forming a three-dimensional image of a pattern to be inspected and apparatus for performing the same
First Claim
1. A method of forming a three-dimensional image for an inspection pattern to be inspected, comprising:
- measuring an intensity of an inspection electromagnetic wave from an inspection pattern on a substrate;
measuring an intensity of a reference electromagnetic wave from a reference pattern on a reference specimen, the reference pattern having substantially similar surface shape and material properties as the inspection pattern;
decomposing a differential function from a reference intensity function, the reference intensity function defined as a continuous function of the intensity of the reference electromagnetic wave with respect to a depth of the reference pattern, the differential function decomposed into a start function and a characteristic function, the start function expressing a vertical profile function of the reference pattern and the characteristic function determining material properties of the reference pattern;
integrating the differential function of the reference intensity function repeatedly to obtain an intensity of a temporary reference electromagnetic wave, the integration including substituting a temporary vertical profile function for the start function for each integration until the intensity of the temporary reference electromagnetic wave is determined to be within an allowable error range;
selecting the substituted temporary vertical profile function as an optimal vertical profile function when the intensity of the temporary reference electromagnetic wave is within the allowable error range; and
combining the surface shape of the inspection pattern and the optimal vertical profile function along a depth of the inspection pattern to form the three-dimensional image for the inspection pattern.
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Accused Products
Abstract
In a method and apparatus for forming a three-dimensional image for an inspection pattern, a reference intensity function of an inspection X-ray is formed in accordance with a continuous scanning depth, and is differentiated with respect to the scanning depth. The differential reference intensity function is decomposed into a start function and a characteristic function. The differential reference intensity function is then repeatedly integrated while a temporary vertical profile function is substituted for the start function until the temporary intensity of a reference X-ray is within an allowable error range. The temporary vertical profile function satisfying the error range is selected as an optimal vertical profile function. A surface shape is combined to the optimal vertical profile function along a depth of the inspection pattern to thereby form the three-dimensional image for the inspection pattern.
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Citations
27 Claims
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1. A method of forming a three-dimensional image for an inspection pattern to be inspected, comprising:
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measuring an intensity of an inspection electromagnetic wave from an inspection pattern on a substrate; measuring an intensity of a reference electromagnetic wave from a reference pattern on a reference specimen, the reference pattern having substantially similar surface shape and material properties as the inspection pattern; decomposing a differential function from a reference intensity function, the reference intensity function defined as a continuous function of the intensity of the reference electromagnetic wave with respect to a depth of the reference pattern, the differential function decomposed into a start function and a characteristic function, the start function expressing a vertical profile function of the reference pattern and the characteristic function determining material properties of the reference pattern; integrating the differential function of the reference intensity function repeatedly to obtain an intensity of a temporary reference electromagnetic wave, the integration including substituting a temporary vertical profile function for the start function for each integration until the intensity of the temporary reference electromagnetic wave is determined to be within an allowable error range; selecting the substituted temporary vertical profile function as an optimal vertical profile function when the intensity of the temporary reference electromagnetic wave is within the allowable error range; and combining the surface shape of the inspection pattern and the optimal vertical profile function along a depth of the inspection pattern to form the three-dimensional image for the inspection pattern. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. An apparatus for forming a three-dimensional image for an inspection pattern to be inspected, comprising:
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an electromagnetic wave generator for generating an electromagnetic inspection wave from the inspection pattern on a substrate and a electromagnetic reference wave from a reference pattern on a reference specimen, the reference pattern having a substantially similar surface shape and material properties as the inspection pattern; a detector for detecting intensities of the electromagnetic inspection wave and the electromagnetic reference wave, and storing each intensity of the electromagnetic waves in accordance with a corresponding scanning depth from which each electromagnetic wave is generated; a function decomposer for decomposing a differential function from a reference intensity function, the reference intensity function defined as a continuous function of the intensity of the electromagnetic reference wave with respect to a depth of the reference pattern, the function decomposer designed to decompose a differential function into a start function and a characteristic function, the start function expressing a vertical profile function of the reference pattern and the characteristic function determining material properties of the reference pattern; and a profile generator for generating the three-dimensional image for the inspection pattern, the profile generator including a selection unit for determining an optimal vertical profile function and a combination unit for combining the surface shape of the inspection pattern and the optimal vertical profile function along a depth of the inspection pattern, the optimal vertical profile function defined as a temporary vertical profile function when an intensity of a temporary electromagnetic reference wave is within an allowable error range and the temporary vertical profile is substituted for the start function. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification