Abstract: A device for positioning a semiconductor substrate is provided comprising magnetic field group formed from a plurality of magnetic fields disposed on a plane in a two-dimensional array. The magnetic fields are provided with a perpendicular orientation relative to the plane and adjacent magnetic fields are directed in alternate directions. Coil sets are formed of a plurality of coils, the coils having a specific dimensional relationship with the magnetic field array. Coil groups are formed by fixedly securing a plurality of these coil sets to each other the coil groups being disposed within the magnetic field group so as to be freely movable along the plane. Electric current is applied to the coils which generates a force in each coil set so as to move the coil set in either one of the longitudinal and lateral directions of the array of magnetic fields, whereby a current-motion converter and a driving device making use of the converter can be formed.

Abstract: A precision positioning device particularly adapted for use in a semiconductor manufacturing operation is provided which comprises a loading table, an armature and a two-dimensional current-motion converter having a magnetic field group and a first coil group. The magnetic field group is formed from a plurality of magnetic fields disposed on a plane in a two-dimensional array. The centers of the magnetic fields of the array are separated by an equal period. The magnetic fields of the array are disposed perpendicular to the plane and adjacent magnetic fields are directed in alternate directions. The first coil group comprises at least first, second, third and fourth coils having a fixed dimensional relationship. More particularly, each coil is provided with an outer dimension approximately equal to three halves of the magnetic fields and a coil width approximately equal to one-half of the period of the array.

Abstract: A first stage adapted to be moved in predetermined directions by a first driving device is provided in a machine base supported from a foundation by an intermediary of resilient means. This first stage is provided a second stage adapted to be moved in the directions at right angles to the directions of movement of the first stage by a second driving device. Upon movement of these respective stages, vibration of the machine base is excited by reaction forces exerted upon the machine base as a result of acceleration and deceleration. These reaction forces are offset by resistive forces generated by first and second force generators respectively. The first and second force generators establish an electromagnetic coupling between the foundation and the machine base.

Abstract: Positioning of a movable body can be achieved at a high resolution by making use of two position signals generated by a position detector, whose magnitudes are sinusoidal functions having different phases of the position of the movable body. On the basis of the two sinusoidal position signals, two bi-level digital position signals having different phase from each other are derived, and digital control for movement of the movable body is effected by making use of these two bi-level digital position signals until the movable body is brought into the proximity of a desired position. Thereafter, control is switched from the digital control to analog control for movement of the movable body, in which a position signal whose manitude is a sinusoidal function of the position of the movable body and has a zero-cross point at the desired position is used as a reference position signal.

Abstract: An apparatus is provided for registering a pattern on a mask plate with a pattern already formed on a semiconductor wafer. A reflector group is provided on the wafer comprising a plurality of reflectors having a predetermined shape, interval and alignment. Two window groups are provided at predetermined positions on the mask plate. Each window group comprises a plurality of windows having a predetermined shape, interval and alignment that corresponds to the shape, interval and alignment of the reflector group. One of the window groups is provided with a staggered phase relationship with the other window group such that when one of the wafer or the mask plate is moved relative to the other, variations in the quantity of light reflected by the reflector group and passed through the respective window groups is used to determine the relative position of the wafer and the mask plate.

Abstract: On a mask to be used in fabrication of semiconductor integrated circuits is formed an electrode outside of an integrated circuit pattern area with the same material as said pattern area in the same thickness as said pattern area, this mask is positioned above a wafer as separated therefrom at a minute gap distance, and the gap distance between the mask and the wafer is measured by detecting an electrostatic capacitance between the electrode and the wafer.

Abstract: A novel linear motor making use of a D.C.

Abstract: A method is provided for registering a pattern on a mask plate with a pattern already formed on a semiconductor wafer. A reflector group is provided on the wafer comprising a plurality of reflectors having a predetermined shape, interval and alignment. Two window groups are provided at predetermined positions on the mask plate. Each window group comprises a plurality of windows having a predetermined shape, interval and alignment that corresponds to the shape, interval and alignment of the reflector group. One of the window groups is provided with a staggered phase relationship with the other window group such that when one of the wafer or the mask plate is moved relative to the other, variations in the quantity of light reflected by the reflector group and passed through the respective window groups is used to determine the relative position of the wafer and the mask plate.

Abstract: A stator and a rotor of a step motor are disposed in an axially staggered relationship with each other so that the rotary shaft of the rotor can be freely displaced in the axial direction with respect to the stator. Around the outer periphery of the rotary shaft are formed screw threads so as to be threadedly engaged with a nut provided on a casing in which the stator of the step motor is fixedly mounted. Thereby the rotational displacement of the rotor can be converted into an axial displacement thereof, and thus a minute amount of desired controlled displacement can be realized with the influence of a backlash between the screw threads on the rotary shaft and the nut eliminated by an electromagnetic characteristic of the step motor.