A guideless stage for aligning a wafer in a microlithography system is disclosed, and a reaction frame is disclosed which isolates both external vibrations as well as vibrations caused by reaction forces from an object stage. In the guideless stage an object stage is disclosed for movement in at least two directions and two separate and independently movable followers move and follow the object stage and cooperating linear force actuators are mounted on the object stage and the followers for positioning the object stage in the first and second directions. The reaction frame is mounted on a base structure independent of the base for the object stage so that the object stage is supported in space independent of the reaction frame. At least one follower is disclosed having a pair of arms which are respectively movable in a pair of parallel planes with the center of gravity of the object stage therebetween. The linear positioning forces of the actuator drive means are mounted and controlled so that the vector sum of the moments of force at the center of gravity of the object stage due to the positioning forces of the drive means is substantially equal to zero. The actuator mounting means can include at least two thin flexible members mounted in series with the primary direction of flex of the members being orthogonal to one another.

Guideless stage with isolated reaction stage

An XY stage for precision movement for use in aligning a wafer in a microlithography system. A main stage supporting the wafer straddles a movable beam that is magnetically driven in a first linear direction in the XY plane. A follower stage, mechanically independent of the main stage, also moves in the first linear (X) direction and its motion is electronically synchronized by a control system with the main stage motion in the X direction. Electromagnetic drive motors include magnetic tracks mounted on the follower stage which cooperate with motor coils mounted on the edges of the main stage to move the main stage in a second linear (Y) direction normal to the X direction. Thus the main stage is isolated from mechanical disturbances in the XY plane since there is no mechanical connections and is lightened by removing the weight of the magnetic tracks from the beam. A cable follower stage moves in the Y direction on the follower stage and supports the cables connecting to the main stage, thereby reducing cable drag. An air circulation system is provided in the magnetic tracks on the follower stage to remove heat from operation of the electromagnetic motors. Air is removed from a central region of each track by a vacuum duct enhanced by air plugs fitting at the two ends of the motor coil assembly on the main stage to contain the air therein.

Precision motion stage with single guide beam and follower stage

A guided stage mechanism suitable for supporting a reticle in a photolithography machine includes a stage movable in the X-Y directions on a base. Laterally surrounding the stage is a rectangular window frame guide which is driven in the X-axis direction on two fixed guides by means of motor coils on the window frame guide co-operating with magnetic tracks fixed on the base. The stage is driven inside the window frame guide in the Y-axis direction by motor coils located on the stage co-operating with magnetic tracks located on the window frame guide. Forces from the drive motors of both the window frame guide and the stage are transmitted through the center of gravity of the stage, thereby eliminating unwanted moments of inertia. Additionally, reaction forces caused by the drive motors are isolated from the projection lens and the alignment portions of the photolithography machine. This isolation is accomplished by providing a mechanical support for the stage independent of the support for its window frame guide. The window frame guide is a hinged structure capable of a slight yawing (rotational) motion due to hinged flexures which connect the window frame guide members.

Window frame-guided stage mechanism

In a rotary-anode type X-ray tube, a rotary-anode is fixed to a cylindrical rotary structure, and a columnar stationary shaft is fitted in the rotary structure. A gap is formed between the rotary structure and the stationary shaft. The gap is filled with a liquid metal lubricant. Spiral grooves are formed in part of the outer surface of the stationary shaft to form a radial sliding bearing between the stationary shaft and the rotary structure. Spiral grooves are formed in the end faces of the stationary shaft to form a thrust sliding bearing between the stationary shaft and the rotary structure. A recess is formed in the stationary shaft to communicate with gaps in the radial sliding bearing. A lubricant storage chamber for storing the liquid metal lubricant is formed in the stationary shaft along the center axis. The storage chamber communicates with communicating holes which radially extend to be open to an outer surface region, of the stationary shaft, in which no spiral grooves are formed. With this structure, a sufficient amount of liquid metal lubricant required for a long-term operation of the sliding bearings can be stored in the X-ray tube, thereby maintaining a stable dynamic pressure type sliding bearing operation for a long period of time.

Rotary anode type X-ray tube

An apparatus capable of high accuracy position and motion control utilizes one or more linear commutated motors to move a guideless stage in one long linear direction and small yaw rotation in a plane. A carrier/follower holding a single voice coil motor (VCM) is controlled to approximately follow the stage in the direction of the long linear motion. The VCM provides an electromagnetic force to move the stage for small displacements in the plane in a linear direction perpendicular to the direction of the long linear motion to ensure proper alignment. One element of the linear commutated motors is mounted on a freely suspended drive assembly frame which is moved by a reaction force to maintain the center of gravity of the apparatus. Where one linear motor is utilized, yaw correction can be achieved utilizing two VCMs.

Electromagnetic alignment and scanning apparatus

The invention relates to a rotary anode X-ray tube having a sliding bearing and a further bearing system. The further bearing system, preferably a magnetic bearing, is constructed so that it can absorb substantially entirely the axial and radial bearing forces, while the sliding bearing, which is preferably constructed as a spiral groove bearing with liquid metal lubrication, is shaped so that it absorbs the bearing forces only for a small fraction. It therefore has only a low friction, but it permits the supply of the anode current and especially an effective cooling of the anode disk.

Rotary anode X-ray tube having a sliding bearing

In an X-ray device which includes an X-ray tube (12) provided with means (15, 22, 23) for influencing the electron flow through the X-ray tube (12), a control voltage for the means for influencing the electron flow is customarily generated by means of a complex circuit which, because of its size, is not suitable to be accommodated within the protective tube housing. This has the drawback that the control voltage for the X-ray tube, usually of high voltage potential, must be supplied additionally to the high-voltage supply. Therefore, it is desirable to realize a simple generation means the control voltage which is suitable for accommodation in the protective tube housing. To this end, the invention proposes a piezoelectric transformer (21, 24, 25) for generating the control voltage for the X-ray tube. The invention also relates to a piezoelectric transformer which is particularly suitable for generating such a control voltage.

X-ray device including a piezoelectric transformer

In an X-ray tube comprising a metal housing portion and an electrode which can be connected to a positive high voltage with respect thereto and which is mounted on a ceramic insulator portion, a conical insulator portion is enclosed by a wall portion, at least the inner surface of which has an insulating effect. A screening sleeve which electrically screens the connection between the insulator portion and the electrode projects into a recess in the wall portion.

X-ray tube comprising an at least partly metal housing and an electrode which carries a positive high voltage with respect thereto

An X-ray tube comprises a cathode structure surrounded by a metal sleeve and supported on a metal base secured to the sleeve by means of an insulator which is provided with a circular groove for supporting a metal screen arranged between the base and the sleeve to prevent electric discharge from the sharp edge of the base.

Diethard Peter

Papers

Rotary anode X-ray tube having a sliding bearing

X-ray device including a piezoelectric transformer

X-ray tube comprising an at least partly metal housing and an electrode which carries a positive high voltage with respect thereto

High-voltage vacuum tube, notably an X-ray tube, comprising a metal sleeve

Hochspannungsvakuumroehre, insbesondere roentgenroehre mit einem metallkolben