Abstract:
PROBLEM TO BE SOLVED: To provide a system which relates to a non-destructive technology for measuring a surface parameter of a sample for measuring the birefringence of a surface, a film thickness, etc. using a polarimetric spectrum. SOLUTION: A polarized sample beam 46 of broadband radiation is focused to the surface of a sample 3 and the radiation polarized by the sample is collected by a mirror system in different planes of incidence. The modulated radiation is analyzed with respect to a polarization plane to provide a polarimetric spectrum. Thickness and refractive information may then be derived from the spectrum. The polarization of the sample beam is altered by the focusing and the sample, and the collection of the modulated radiation is repeated employing two different apertures 28 to detect the presence or absence of a birefringence axis in the sample. In the other preferred embodiment, the technology may be combined with ellipsometry for determining the thicknesses and refractive indices of thin films. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To detect the size and shape of an irradiation region on an object in a spectroscopic ellipsometer. SOLUTION: In a spectroscopic ellipsometer 1 of a film thickness measuring apparatus 10, reflected light reflected on the measurement surface 91 of a substrate 9 is divided into a first polarized light which is a linearly polarized component in a predetermined polarization direction, and a second polarized light which is a linearly polarized component, in a polarization direction perpendicular to the first polarized light, by an analyzer 42 of a light-receiving part 4. The polarization state at each wavelength of the reflected light is measured with the first polarized light, and the size and shape of the irradiation region on the measurement surface 91 of the substrate 9 are detected by using the second polarized light. In the spectroscopic ellipsometer 1, since the detection of the size and shape of the irradiation region is performed with the second polarized light which is a polarized component that is not used in the measurement of the polarization state, of the reflected light from the measurement surface 91, to detect the size and shape of the irradiation region on the measurement surface 91 of the substrate 9 can be detected with high accuracy, while maintaining the measurement accuracy of the polarization state of the reflected light to be high. COPYRIGHT: (C)2009,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To highly accurately adjust the focus of a spectroscopic ellipsometer. SOLUTION: In the spectroscopic ellipsometer 1, light from a light source 31 is made incident at an angle onto the measuring surface 91 of a substrate 9 via an optical system of an illumination part 3 and guided to a light-receiving device 422 via an optical system of a light-receiving part 4 to analyze polarization on the basis of the spectral intensity of reflected light from the measuring surface 91 acquired by the light-receiving device 422. In the adjustment of the focus of the spectroscopic ellipsometer 1, the focal position of the measuring surface 91 is determined on the basis of the sum quantity of light in a prescribed wavelength band of the reflected light from the measuring surface 91 acquired by the light-receiving device 422. By sharing an optical system used for polarization analysis and an optical system used for focus adjustment in this way in the spectroscopic ellipsometer 1, it is possible to exclude the effects of changes in the optical systems due to temperature changes etc. and perform highly accurate focus adjustment. COPYRIGHT: (C)2009,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To prevent a band width and an insertion loss of a filter from increasing according to that a tilt angle of an (optical spectrum analyzer) interference filter is fluctuated and an OSA from becoming unsuitable for measurement of an optical signal in a DWDM(high density wavelength division multiplex) optical communication system. SOLUTION: The OSA contains a polarization correcting device 12. The polarization correcting device 12 splits spatially the orthogonal polarization component of the added optical signal to make it an independent light beam, and rotates the relative polarization component of the light beam, and constitutes so that the light beam is made multi-path constitution in the single polarization state, and is made incident on a tunable interference filter 14. The light beam is directed, and passes through the areas 14a, 14b of the interference filter 14 placed on a contour line of a substantially equal central wavelength, and filter band width are narrowed equally by respective plural paths passing through the interference filter 14. The narrow band width and a low insertion loss are kept over a wide tuning range by tilting the interference filter around a tilt axis A intersecting with the area of the interference filter 14 placed on the contour line of the substantially equal central wavelength.
Abstract:
PURPOSE:To measure the reflected spectrum accurately, by separately measuring and recording the reflected spectrums of light beams, which are polarized into two different angles, and operating the reflected spectrum with regard to the light at the other angle of polarization based on the two kinds of spectrums. CONSTITUTION:A sample light beam and a compensating light beam are inputted to a detector 4. These light beams are converted into electric signals. The signals are sent to an A/D converter 10 through an amplifier 9 and further converted into a digital signals. The digital signals are processed by a computer 11. Based on the command from an input device 12, the reflection spectrum of polarized light at 0 deg. (a) is measured. The measured result is stored in a memory device 13. Then the reflected spectrum of polarized light at 90 deg. (b) is measured and stored. Thereafter, the reflected spectrum at theta degrees is measured by an operator 14 based on the expression 1 in the Figure.