Method for defect determination in fine concave-convex pattern and method for defect determination on patterned medium
In the inspection of a defect in a fine concave-convex pattern, a spectral waveform of a detection area of an inspection object is detected, area determination as to which area section determined by a pattern type of the inspection object the detection area belongs to is performed, a feature calculation equation and a determination index value which correspond to a determined area section and vary according to defect type is selected, feature calculation on the spectral waveform data in accordance with the selected feature calculation equation is performed, and a calculated feature value and the selected determination index value are compared to perform determination processing according to defect type.
1. A method for determining a defect in a fine concave-convex pattern when a feature of an inspection object is detected via scatterometry in inspection of the fine concave-convex pattern, the method comprising:
a) detecting a spectral waveform of a detection area of the inspection object;
b) performing an area determination to determine an area section to which the detection area belongs based on a pattern type of the inspection object in accordance with design information or the spectral waveform;
c) selecting a feature calculation equation and at least one determination index value corresponding to the determined area section, based on a result of the area determination;
d) performing feature calculation on data for the detected spectral waveform in accordance with the selected feature calculation equation;
e) comparing a calculated feature value with the at least one selected determination index value to perforin determination processing; and
f) performing defect type determination based on a result of determination processing.
2. The method for determining a defect in a fine concave-convex pattern according to claim 1 , wherein performing the area determination comprises classifying the pattern type of the inspection object into a periodic pattern and a non-periodic pattern.
3. The method for determining a defect in a fine concave-convex pattern according to claim 1 , wherein performing determination processing comprises:
comparing, when an optical signal changes depending on the pattern type of the inspection object and the defect type, an optical signal variation of a non-defective pattern and an optical signal change caused by a defect, and
capturing a significant signal change.
4. The method for determining a defect in a fine concave-convex pattern according to claim 3 , comprising:
selecting a wavelength based at least in part on an amplitude of the wavelength, and
determining a defect based on the amplitude of the selected wavelength.
5. The method for determining a defect in a fine concave-convex pattern according to claim 1 , comprising selecting a predetermined determination index value according to pattern type based on the area determination.
6. The method for determining a defect in a fine concave-convex pattern according to claim 1 , wherein the feature calculation equation is:
F i (λ)=α·ƒ(λ 1 )+β·ƒ(λ 2 )+γ·ƒ(λ 3 )+ . . .
where Fi(λ) is the feature calculation equation, f(λk) is a reflectance value of the spectral waveform with respect to a wavelength λk, α, γ . . . are coefficients, i=1, 2, 3 . . . , and k=1, 2, 3 . . . .
7. The method for determining a defect in a fine concave-convex pattern according to claim 1 , wherein the feature calculation equation is:
F
i
(
λ
)
=
∑
k
=
0
n
{
α
k
·
f
(
λ
k
)
+
β
k
·
f
2
(
λ
k
)
+
γ
k
·
f
3
(
λ
k
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+
...
}
where Fi(λ) is the feature calculation equation, f(λk) is a reflectance value of the spectral waveform with respect to a wavelength λk, αk, βk, γk . . . are coefficients, i=1, 2, 3 . . . , and k=1, 2, 3 . . . .
8. A method for determining a defect on a patterned medium via scatterometry, the method comprising:
a) detecting a spectral waveform of a detection area of a patterned medium;
b) performing an area determination to determine an area section to which the detection area belongs based on a pattern type of the patterned medium in accordance with design information or the spectral waveform;
c) selecting a feature calculation equation and at least one determination index value corresponding to the determined area section, based on a result of the area determination;
d) performing feature calculation on data for the detected spectral waveform in accordance with the selected feature calculation equation;
e) comparing a calculated feature value with the at least one selected determination index value to perform determination processing; and
f) performing defect type determination based on a result of determination processing.
9. The method for determining a defect on a patterned medium according to claim 8 , wherein the defect type includes a void, a foreign substance, and a scratch.
10. The method for determining a defect on a patterned medium according to claim 8 , wherein the area section includes a data area and a servo area.
11. The method for determining a defect on a patterned medium according to claim 10 , wherein the data area in the area section is divided into an inner periphery area, a middle periphery area, and an outer periphery area.
12. The method for determining a defect on a patterned medium according to claim 10 , wherein the servo area in the area section is divided into an address area, a clock area, and a tracking area.