A projection exposure apparatus including an irradiation optical system including a light source and irradiating a mask with irradiation light beams, a projection optical system for projecting an image of a pattern of the mask on a substrate, a plurality of first fly-eye type optical integrators each having an emission side focal plane disposed on a Fourier transformed surface with respect to the pattern of the mask in the irradiation optical system or on a plane adjacent to the same and having a center located at a plurality of positions which are eccentric from the optical axis of the irradiation optical system, a plurality of second fly-eye type optical integrators each having an emission side focal plane disposed on a Fourier transformed plane with respect to the incidental end of each of a plurality of the first fly-eye type optical integrators or on a plane adjacent to the same and being disposed to correspond to a plurality of the first fly-eye type optical integrators, and a light divider for dividing and causing the irradiation light beams from the light source to be incident on each of a plurality of the second fly-eye type optical integrators.

Projection exposure apparatus

A device for use in a dental or medical application to obtain three-dimensional contour information comprises a multiplicity of arm segments, first mounting elements for connecting the arm segments to one another to form an articulated assembly of the arm segments. A second mounting element serves to fix the articulated assembly relative to a person's head, while a third mounting element is provided for attaching a diagnostic or medical treatment instrument to the articulated assembly at a point spaced from the second mounting element. A feedback component or components are operatively coupled with at least some of the arm segments for providing electrical signal feedback data as to positions of the arm segments relative to one another, thereby providing information as to the position of the instrument relative to the person's head.

Device for obtaining three dimensional contour data and for operating on a patient and related method

A method for use in forming a preparation in a patient's jaw comprises the steps of (a) generating electrically encoded data specifying pre-existing dental structure in the patient's jaw, (b) transmitting the data to a computer, (c) operating the computer to generate, on a monitor connected to the computer, a graphic representation of the pre-existing structure, (d) further operating the computer to predetermine an optimal position and an optimal orientation of a material removal tool with respect to the pre-existing structure, and (e) additionally operating the computer to generate, on the monitor, a graphic representation of the tool in the optimal position and the optimal orientation relative to the pre-existing structure. The method may be used to conduct a practice operation on the patient. In such a practice operation, the dental practitioner orients a dental type instrument (e.g., a probe or a drill) in juxtaposition to the pre-existing structure at the optimal position (shown on the monitor). The computer is provided with electrical feedback or signals as to the actual position and the actual orientation of the instrument. The computer is then operated to automatically determine an angle between the optimal orientation and the actual orientation. The computer then alerts the dental practitioner as to the deviation, if any, between the instrument and the optimal position and orientation thereof.

Method for facilitating dental diagnosis and treatment

An apparatus (20) for measuring the thickness of a thin film layer (32) on substrate (28) includes a probe beam of radiation (24) focused substantially normal to the surface of the sample using a high numerical aperture lens (30). The high numerical aperture lens (30) provides a large spread of angles of incidence of the rays within the incident focused beam. A detector (50) measures the intensity across the reflected probe beam as a function of the angle of incidence with respect to the surface of the substrate (28) of various rays within the focused incident probe beam. A processor (52) functions to derive the thickness of the thin film layer based on these angular dependent intensity measurements. This result is achieved by using the angular dependent intensity measurements to solve the layer thickness using variations of the Fresnel equations. The invention is particularly suitable for measuring thin films, such as oxide layers, on silicon semiconductor samples.

Method and apparatus for measuring thickness of thin films

A method for use in preparing a dental prosthesis comprises the step of receiving an electrical signal encoding geometric specifications of a substructure of the prosthesis, the specifications including dimensions and shape of a tooth preparation at a dental site at which the prosthesis is to be affixed and the configuration of the substructure. In a subsequent step performed in response to the electrical signal, a computer is operated to automatically select a first mold component having a surface corresponding in dimensions to the tooth preparation and to automatically select a second mold component to produce, in cooperation with the first mold component, a mold cavity having dimensions and configuration corresponding to dimensions and configuration of the substructure. The first mold component and the second mold component are placed in predetermined relative positions to form the mold cavity and the mold cavity is filled with a quantity of a fluidic solidifiable dental material, i.e., a precious metal, semi-precious metal, alloy or other usable dental material.

Method, system and mold assembly for use in preparing a dental prosthesis

The gaussian energy distribution common to all laser beams is a serious handicap in most laser beam applications for machining material, such as for drilling, welding and the like. This is especially true in welding extremely thin metal sheets, as in the manufacture and assembly of the transducers of modern magnetic disk files. According to the subject invention, a laser beam is directed to a glass cone or axicon which converts the gaussian energy distribution of the laser beam to one more uniform in cross-section. Depending on the distance of the workpiece from the exit side of the axicon, the energy distribution of the radiation impinging onto the workpiece will be either uniform, saddle shaped or annular cross-section. It has been discovered that saddle shaped or annular energy distributions are optimal for welding very thin metal sheets by a laser beam since the heat dissipation in the center of a welding spot is a minimum and that at the periphery of the laser beam depends on the material, size and shape of the workpiece, which parameters can be matched by adjusting the distance between the axicon and the workpiece.

Apparatus for machining material

To align a grating on a mask with respect to an equivalent grating of a wafer in a photolithographic system where the mask is imaged by an imaging system onto the wafer, symmetrical diffraction orders (u°+1, u°-1) are focussed on the wafer grating and diffracted a second time to return colinear with the optical axis and to be deflected by a beam splitter to a photo detector The intensity of the superimposed outbeams depends on the relative phase differences of the diffracted beams, and, hence, on the displacements of the mask and wafer gratings The phase of the electrical output signal is determined by introducing periodic phase differences in the diffracted beams of the mask grating by a wobbling parallel glass plate For simultaneous X-, Y- alignment, crossed gratings are used that operate on two pairs of diffracted beams The polarization direction of one of these pairs is rotated by 90° before impinging on the second grating so that each pair of diffracted beams can be fed to a separate photodetector In a step-and-repeat photolithographic system, optical fine alignment can be performed by adjusting a fixed tilt angle of the glass plate after having determined the amount of misalignment

Interferometric mask-wafer alignment

A surface is subjected to a light field whose intensity is periodically modulated in a vertical direction to evaluate a scattered light pattern. The light field is obtained from interference between a first or central beam with vertical incidence and two symmetrical laterally disposed beams with oblique incidence. All beams are focussed to a common spot if the profile is obtained by scanning the surface or are superimposed as collimated beams if large area profiling is desired. The surface is imaged onto a diaphragm which selects appropriate locations of the surface for measurements by a photodetector to record sinusoidal intensity variations that are obtained when the light is periodically shifted in a vertical direction by phase modulating the first or central beam with respect to the lateral beams.

Method and arrangement for optically determining surface profiles

A method and apparatus is described for making absolute and relative distance measurements optically. A grating, or gratings, is located on the object whose displacement is to be measured, or on a surface in contact with the object. Two perpendicularly polarized light beams interact with the grating to produce a phase difference therebetween. This phase difference is a measure of the displacement of the object, and can be compensated for in order to determine the exact displacement of the object. The relative displacement between two objects can be measured in a similar way, there being gratings on the two objects. One of the light beams strikes one grating while the other strikes the second grating. If there is perfect alignment between the gratings on the two objects, there will be no phase difference in the diffracted light from the gratings. If there is misalignment between the objects, a phase difference between the diffracted signals will be produced indicative of this misalignment.

Method and arrangement for optical distance measurement

In an interferometer wherein there is provided means for directing two linearly polarized beams having their polarizations perpendicular to each other onto a surface at different angles of incidence and means for recombining the beams reflected from the object into a combined beam, the improvement wherein means for periodically varying the phase of one component of the combined beam is provided and wherein the amount of change in phase between the two component beams of the combined beam when an amplitude sensing means senses a maximum or a minimum amplitude is a measure of the topographic height variations of the object surface which is irradiated.

Günter Makosch

Papers

Apparatus for machining material

Interferometric mask-wafer alignment

Method and arrangement for optically determining surface profiles

Method and arrangement for optical distance measurement

Interferometric measurement apparatus and method having increased measuring range