Method and apparatus for measurements of patterned structures
First Claim
1. A method for measuring at least one desired parameter of a patterned structure, which represents a grid having at least one cycle formed of at least two metal-containing regions spaced by substantially transparent regions with respect to incident light thereby defining a waveguide, the structure having a plurality of features defined by a certain process of its manufacturing, the method comprising the steps of:
- a) providing an optical model, which is based on at least some of said features of the structure, on relation between a wavelength range of the incident light to be used for measurements and a space size between the two metal-containing regions in the grid cycle, and a skin depth of said metal, and is capable of determining theoretical data representative of photometric intensities of light components of different wavelengths specularly reflected from the structure and of calculating said at least one desired parameter of the structure;
b) locating a measurement area for applying thereto spectrophotometric measurements, wherein said measurement area is a grid cycles containing area;
c) applying the spectrophotometic measurements to said measurement area by illuminating it with incident light of a preset substantially wide wavelength range, detecting light component substantially specularly reflected from the measurement area, and obtaining measured data representative of photometric intensities of each wavelength within said wavelength range;
d) analyzing the measured data and the theoretical data and optimizing said optical model until said theoretical data satisfies a predetermined condition; and
e) upon detecting that the predetermined condition is satisfied, calculating said at least one parameter of the structure.
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Accused Products
Abstract
A method for measuring at least one desired parameter of a patterned structure having a plurality of features defined by a certain process of its manufacturing. The structure represents a grid having at least one cycle formed of at least two metal-containing regions spaced by substantially transparent regions with respect to incident light defining a waveguide. An optical model is provided, which is based on at least some of the features of the structure defined by a certain process of its manufacturing, and on the relation between a range of the wavelengths of incident radiation to be used for measurements and a space size between the two metal-containing regions in the grid cycle, and a skin depth of said metal. The model is capable of determining theoretical data representative of photometric intensities of light components of different wavelengths specularly reflected from the structure and of calculating said at least one desired parameter of the structure. A measurement is area is located and spectrophotometric measurements are applied to the measurement area, by illuminating it with incident light of a preset substantially wide wavelength range. A light component substantially specularly reflected from the measurement area is detected, and measured data representative of photometric intensifies of each wavelength within the wavelength range is obtained. The measured and theoretical data are analyzed and the optical model is optimized until the ,theoretical data satisfies a predetermined condition. Upon detecting that the predetermined condition is satisfied, said at least one parameter of the structure is calculated.
28 Citations
26 Claims
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1. A method for measuring at least one desired parameter of a patterned structure, which represents a grid having at least one cycle formed of at least two metal-containing regions spaced by substantially transparent regions with respect to incident light thereby defining a waveguide, the structure having a plurality of features defined by a certain process of its manufacturing, the method comprising the steps of:
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a) providing an optical model, which is based on at least some of said features of the structure, on relation between a wavelength range of the incident light to be used for measurements and a space size between the two metal-containing regions in the grid cycle, and a skin depth of said metal, and is capable of determining theoretical data representative of photometric intensities of light components of different wavelengths specularly reflected from the structure and of calculating said at least one desired parameter of the structure;
b) locating a measurement area for applying thereto spectrophotometric measurements, wherein said measurement area is a grid cycles containing area;
c) applying the spectrophotometic measurements to said measurement area by illuminating it with incident light of a preset substantially wide wavelength range, detecting light component substantially specularly reflected from the measurement area, and obtaining measured data representative of photometric intensities of each wavelength within said wavelength range;
d) analyzing the measured data and the theoretical data and optimizing said optical model until said theoretical data satisfies a predetermined condition; and
e) upon detecting that the predetermined condition is satisfied, calculating said at least one parameter of the structure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. An apparatus for measuring at least one desired parameter of a patterned structure that represents a grid having at least one grid cycle formed of a least two metal-containing regions spaced by substantially transparent regions with respect to incident light defining a waveguide, the structure having a plurality of features defined by a certain process of its manufacturing, the apparatus comprising:
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a spectrophotometer illuminating a measurement area by incident light of a preset substantially wide wavelength range and detecting a specular reflection light component of light reflected from the measurement area for providing measured data representative of photometric intensities of detected light within said wavelength range; and
a processor unit coupled to the spectrophotometer, the processor unit comprising a pattern recognition software and a translation means so as to be responsive to said measured data and locate measurements, the processor being operable for applying an optical model, based on at least some of said features of the structure, on relation between wavelength range of the incident light to be used for measurements and a space size between the two metal-containing regions in the grid cycle, and a skin depth of said metal, for providing theoretical data representative of photometric intensities of light specularly reflected from the structure within said wavelength range and calculating said at least one desired parameter, and comparing said measured and theoretical data and detecting whether the theoretical data satisfies a predetermined condition. - View Dependent Claims (22, 23, 24, 26)
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25. A working station for processing wafers progressing on a production line, wherein each of said wafers is a patterned structure that represents a grid having at least one grid cycle formed of at least two metal-containing regions spaced by substantially transparent regions with respect to incident light defining a waveguide, and the structure has a plurality of features defined by a certain process of its manufacturing, the work station comprising an inspection apparatus and a support frame for supporting the wafer within an inspection plane, wherein the inspection apparatus comprises:
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a spectrophotometer illuminating a measurement area by an incident light of a preset substantially wide wavelength range and detecting a specular reflection light component of light reflected from the measurement area for providing measured data representative of photometric intensities of detected light within said wavelength range; and
a processor unit coupled to the spectrophotometer, the processor unit comprising a pattern recognition software and a translation means so as to be responsive to said measured data and locate measurements, the processor being operable for applying an optical model, based on at least some of said features of the structure and on relation between the wavelength range of the incident light to be used for measurements and a space size between the two metal-containing regions in the grid cycle, and a skin depth of said metal, for providing theoretical data representative of photometric intensities of light specularly reflected from the structure within said wavelength range and calculating said at least one desired parameter, and comparing said measured and theoretical data and detecting whether the theoretical data satisfies a predetermined condition
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Specification