摘要:
A method of measuring light reflected by a test sample with a microscopic photometric system. The test sample placed in an in-focus position of an objective is irradiated, and light reflected by the test sample is measured. Stray light generated by microscopic optics including the objective is measured with the test sample placed in an out-of-focus position of the objective. Light actually reflected by the test sample is determined from a difference between the reflected light and the stray light measured.
摘要:
An optical scanner according to the present invention comprises a collimator lens, a cylindrical lens, a light deflector, an f-θ lens and an anamorphic lens. The f-θ lens is constituted by three groups of five lenses, i.e., a first cemented lens formed by bonding a first lens and a second lens to each other, a second cemented lens formed by boding a third lens and a fourth lens to each other and a fifth lens having positive refracting power. The f-θ lens is formed to satisfy relational expressions L/f
摘要:
An optical scanner according to the present invention comprises a first imaging optical system consisting of a collimator lens and a cylindrical lens, a light deflector reflecting/deflecting a light beam for scanning, and a second imaging optical system consisting of an f-&thgr; lens and an anamorphic lens. The f-&thgr; lens has three groups of lenses, i.e., a first lens having negative refracting power, a second lens having positive refracting power and a third lens having positive refracting power. The f-&thgr; lens is formed to satisfy relational expressions L/f
摘要:
An illumination apparatus is disclosed which efficiently irradiates an irradiation surface without destroying the symmetry of an illuminance distribution at the irradiation surface. A light source is displaced from a center of curvature of a spherical mirror in a direction in a displacement plane which includes an axis of symmetry of the spherical mirror so as to form a light source image at a position off the light source. Due to this, a ray from the spherical mirror passes off the light source (i.e., the position of the light source image), and therefore, a reflection ray is not shielded, absorbed nor otherwise disturbed by the light source, which in turn prevents deterioration in the efficiency of utilization of light. Further, the light source, the spherical minor and the lens are assembled into a light source unit which is inclined at an angle about a principal point of the lens with respect to a central axis of the irradiation surface and displaced a certain distance in a displacement direction which is perpendicular to the central axis. Hence, the illuminance distribution at the irradiation surface is adjusted and the symmetry of the illuminance distribution at the irradiation surface is improved.
摘要:
A film thickness measuring apparatus measures the thickness of a thin film which is formed on a substrate with an excellent reproducibility regardless of inclination of a surface of a sample. Since an illumination system (20) includes a glass rod (GL) which corrects wavelength dependencies of luminance distributions of light sources (HL, DL), even when an eclipse in reflected light due to inclination of a sample (SP) decreases the energy of the reflected light, a spectral distribution of the reflected light entering a spectroscopic unit (40) is maintained with almost no change. A control unit (50) performs data conversion of multiplying an actual spectral reflectance by a ratio of an average of the actual spectral reflectance which is determined based on an output from the spectroscopic unit (40) to an average of a calibrated spectral reflectance and thereafter calculates a deviation between the two spectral reflectances. As a result, the film thickness is accurately measured while preventing an influence of inclination of the sample (SP).
摘要:
Light of an observation wavelength range is irradiated upon a sample object to measure spectral reflection ratios, and an waveform is developed from the spectral reflection ratios. Based on the total number of peaks and valleys found in the interference waveform and two wavelengths specified within the observation wavelength range, possible ranges for the film thicknesses of the respective transparent films are determined. While changing tentative film thicknesses of the respective transparent films each by a predetermined film thickness pitch within the film thickness ranges, a deviation between theoretical spectral reflectance and measured spectral reflectance with respect to the tentative film thicknesses is calculated to thereby find a film thickness combination which causes the deviation to be minimum.