Abstract:
A method and apparatus for monitoring process fluids used in the manufacture of semiconductor components and other microelectronic devices relies upon detection of the phase shift of a pair of optical energy beams encountering a bubble or particle in the fluid. The system distinguishes between bubbles and particles having indices of refraction greater than the surrounding fluid and between different types and sizes of particles.
Abstract:
An apparatus is described for classifying particles and includes an optical system for transmitting to a focal plane which includes at least one particle, two substantially parallel optical beams, the beams being initially mutually coherent but of different polarizations. The beams are displaced and focused in the focal plane. A further optical system is positioned in the path which the beam takes after depating from the focal plane and combines the beams so that a particle-induced phase shift in one beam is manifest by a change in elliptical polarization of the combined beams. A first detector is responsive to the beam's intensity along a first polarization axis to produce a first output and a second detector is responsive to the beams intensity along a second polarization axis to produce a second output. The first and second outputs are added to provide an extinction signal and, in a separate device, are subtracted to provide to phase shift signal. The extinction signal and phase shift signal are both fed to a processor which classifies a particle in accordance therewith.
Abstract:
An apparatus for measuring changes in a variable interference section of an interferometer comprises a laser source for producing beams of the frequency n.sub.1 and the frequency n.sub.2, polarizing beam splitters for producing cross-polarized partial beams of frequency n.sub.1 or n.sub.2, modulators for displacing the frequency of one of the partial beams by frequency f.sub.1 or f.sub.2, a pair of deflecting mirrors in each case and polarizing beam splitters for combining the partial beam n.sub.1, n.sub.1 +f.sub.1, n.sub.2, n.sub.2 +f.sub.2. The apparatus further includes two photodetectors, upstream of which are arranged a polarizer, a Michelson interferometer, a non-polarizing beam splitter for splitting the partial beams in each case into a measuring light beam or a reference light beam. The reference light beam passes to an associated photodetector. The measuring light beam passes into the Michelson interferometer and then to the associated photodetector. The signals of the photodetectors are demodulated according to the amplitude and the phase difference between the two demodulated signals is determined. This phase difference is only dependent on the position of a measurement object and the equivalent wavelength of the difference n.sub.1 -n.sub.2. A method for measuring changes by determining positions or distances is performed by the apparatus.
Abstract:
The present apparatus includes a two-frequency, Zeeman-effect laser and matched, doubly refracting crystals in the construction of an accurate interferometer. Unlike other interferometric devices, the subject invention exhibits excellent phase stability owing to the use of single piece means for producing parallel interferometer arms, making the interferometer relatively insensitive to thermal and mechanical instabilities. Interferometers respond to differences in optical path length between their two arms. Unlike many interferometric techniques, which require the measurement of the location of interference fringes in a brightly illuminated background, the present invention permits the determination of the optical path length difference by measuring the phase of an electronic sine wave. The present apparatus is demonstrated as a differential thermooptic spectrometer for measuring differential optical absorption simply and accurately which is but one of many applications therefor. The relative intensities of the heating beams along each arm of the interferometer can be easily adjusted by observing a zero phase difference with identical samples when this condition is obtained.
Abstract:
An optical system for analyzing and correcting wave fronts comprising a deformable mirror for correcting wave fronts and a system for analyzing and detecting phase distortion, an interferometer with lateral duplication constituting the analysis system, receiving the wave front for analysis and duplicating it and deducing from two neighboring wave fronts obtained signals to control deformation of the deformable mirror, wherein this lateral duplication interferometer is a polarization interferometer consisting of a Wollaston double-refractive biprism with an angle .theta., the two prisms being assembled head to tail and cut parallel to the crystallographic axis such that the respective axes are parallel and perpendicular to the edges of the prisms, a polarizer and an analyzer on either side of the biprism and an oscillating optical member on the path of the biprism.
Abstract:
A method for measuring an optical length of light path based on use of multiple-beam interference of light and carried into effect by forming an original light beam with two collinear components having mutually independent polarizations and different frequencies in such a manner that when forming each of the following interfering light beams from the preceding one, polarizations of the light components having different frequencies are mutually converted, whereupon the interfered light is converted into an electric signal and its phase is measured, by which the light path optical length is determined. A laser interferometer carrying said method into effect comprises: a laser and arranged consecutively along the direction of run of the light beam: a device for offsetting the frequency of one of the light components, reflecting elements, a polarizing element for separating the light of the interfering beams according to polarization, and a photoelectric converter of the interfered light into an electric signal, as well as a unit for measuring the phase of an electric signal, connected to the photoelectric converter and also a birefringent plate located between the reflecting elements and adapted for mutual conversion of polarizations of the two light components.
Abstract:
피검광학계에 편광방향이 서로 다른 복수의 직선 편광의 광을 조사하고, 상기 피검광학계의 복굴절량(R)과 진상축(φ)을 포함한 편광특성을 측정하는 방법은, 상기 피검광학계에 편광방향(θ)을 가진 직선편광의 광을 조사하는 스텝과, 상기 피검광학계를 투과한 광의 중심량(P)를 취득하는 스텝과, P=-R·cos(2θ-φ) 또는 P=R·cos(2θ-φ)로부터 상기 복굴절량(R)과 상기 진상축(φ)을 취득하는 스텝을 포함하고 있다.
Abstract:
A measurement method is provided to simply measure polarization property of a optical system to be detected without an optical device such as a wavelength plate and a polarizer. A measurement method includes the steps of illuminating linear polarization in a direction of 0° by an illumination optical system(1002), measuring a centroid amount of light transmitting a projection optical system to save the measured value into a data process system(1004), rotating a polarization unit to repeat a measurement by an illumination having a different polarization direction and repeating a store of the result in whole predetermined polarization directions(1006,1008), analyzing a polarization property on the data process system using the value of saved measurement results and each of the polarization directions corresponding to each of the saved measurement results to calculate an amount of correction of the optimized projection optical system, a reticle pattern, and an illumination optical system(1010), and saving the amount of correction into an exposure device as feedback(1012).
Abstract:
본 발명의 파장 어긋남 측정장치는, 광원으로부터 사출된 광속의 파장의 어긋남을 측정하는 파장 어긋남 검출 센서(WLCD1)이며, 광원으로부터 사출된 광속을 복수의 광속으로 분할하고, 상기 복수의 광속 중의 2광속을 합성해서 간섭광을 생성하는 빔 스플리터(BS2)와, 빔 스플리터(BS2)에 의해 분할된 2광속의 광로 길이차가 일정하게 되도록 설치된 스페이서 부재(SP)와, 빔 스플리터(BS2)에 의해 생성된 간섭광을 검출하는 복수의 광전 센서(PD)를 포함한다. 상기 복수의 광전 센서(PD)는, 상기 간섭광에 근거해서 서로 위상이 어긋난 복수의 간섭 신호들을 출력하여, 상기 복수의 간섭 신호들을 이용해서 파장 어긋남을 산출한다. 파장 어긋남, 광원, 간섭 측정, 광전 센서, 빔 스플리터
Abstract:
PURPOSE: A wavelength shift measuring device, a light source device, an interference measurement device, an exposure device, and a manufacturing method of the devices are provided to measure the precise light source wavelength. CONSTITUTION: A wavelength shift measuring device comprises an optical element, a spacer member and a photo electronic control sensor. The optical element partitions the flux injected from the light source into a plurality of fluxes. The optical element is created the coherent light and synthesizes 2 flux among a plurality of fluxes. The photo electronic control sensor outputs a plurality of interferential signals in which phase each other crosses each other based on the coherent light.