In a method for aligning first and second objects relative to each other, according to this invention, the first and second objects are arranged opposite to each other, and are aligned in a direction perpendicular to their opposing direction. A grating pattern is formed, as an alignment mark, on the first object, and a checkerboard-like grating pattern is formed, also as an alignment mark, on the second object. A light beam emitted from an alignment light source is radiated onto the checkerboard-like grating pattern of the second object. The light beam diffracted by the checkerboard-like grating pattern is guided onto the grating pattern of the first object. The light beam diffracted by the grating pattern of the first object is detected by a detector. Since the light beam emitted from the light source is diffracted by the checkerboard-like grating pattern, a relative position of the first and second objects can be detected, irrespective of the distance therebetween. The first and second objects are accurately aligned, based on the detection result. This invention can be applied to a method for aligning a mask and a wafer when a circuit pattern pre-formed on the mask is to be transferred onto the wafer.
Two pieces of semiconductor wafers 10.sub.1 and 10.sub.2 to be stacked and fused together are secured to wafer holders 20.sub.1 and 20.sub.2 respectively, and are then integrally held at a wafer hold unit 2. Rough position alignment is first applied to these semiconductor wafers 10.sub.1 and 10.sub.2 while supplying infrared light thereto from an infrared light source 30 of an infrared light system 3 for detection of a resultant lattice image at a detection unit 5. Then, fine position, alignment is performed while supplying laser light from an laser light source 40 of a laser light system 4 for detection of a resultant diffraction image at the detection unit 5. Thus, in the manufacture of a semiconductor-device having its crystal structure with three-dimensional periodical refractive index distribution employing precision multilayer stack methods by using a wafer fusion, a method and apparatus for manufacturing the semiconductor device is realized which is capable of achieving precise position alignment between lattice layers stacked over each other with reduced complexity in position alignment thereof.
Two pieces of semiconductor wafers 10.sub.1 and 10.sub.2 to be stacked and fused together are secured to wafer holders 20.sub.1 and 20.sub.2 respectively, and are then integrally held at a wafer hold unit 2. Rough position alignment is first applied to these semiconductor wafers 10.sub.1 and 10.sub.2 while supplying infrared light thereto from an infrared light source 30 of an infrared light system 3 for detection of a resultant lattice image at a detection unit 5. Then, fine position alignment is performed while supplying laser light from an laser light source 40 of a laser light system 4 for detection of a resultant diffraction image at the detection unit 5. Thus, in the manufacture of a semiconductor device having its crystal structure with three-dimensional periodical refractive index distribution employing precision multilayer stack methods by using a wafer fusion, a method and apparatus for manufacturing the semiconductor device is realized which is capable of achieving precise position alignment between lattice layers stacked over each other with reduced complexity in position alignment thereof.
The measuring device for track building machines comprises an optical receiver device having two lenses (1, 2) aligned in one axis (3) and in each case at least one associated sensor strip (4, 5). The projections of light sources (A, B, C) disposed outside the receiver device onto the sensor strips (4, 5) produce signals which are evaluated and determine the size of the angle of the light source in relation to the optical axis. The provision of light-sensitive sensor strips (4, 5) makes it possible to dispense in an advantageous manner with mechanically rotating components in the receiver device.
A pair of masks is designed to expose an upper surface and a lower surface of a silicon wafer. Each mask includes, outside its operative surface area, corresponding to the surface of the silicon wafer, identical or complementary sighting marks.
A method for achieving three-dimensional alignment of a pair of optical components, and apparatus for supporting such method, is initiated by fixing one of the optical components at a selected location on a semiconductor substrate. Subsequently, the other optical component and its associated submount are attached to a pair of coupled motion stages. A reference signal, to which the first optical component has been aligned, is transmitted to the other component and to a detector. That detector is positioned to measure changes in a selected characteristic of the reference signal, such as changes in optical power, as the position of the second optical component and its submount are manipulated. Through the use of a feedback loop, the second component and submount are moved in a pattern until an optimal alignment is converged upon.
