Abstract:
A system and method are used to protect a mask from being contaminated by airborne particles. They include providing a reticle secured in a two-part cover. The two part cover includes a removable protection device used to protect the reticle from contaminants. The cover can be held inside a pod or box that can be used to transport the cover through a lithography system from an atmospheric section to a vacuum section. While in the vacuum section, the removable cover can be moved during an exposure process during which a pattern on the reticle can be formed on a wafer.
Abstract:
A lithographic projection apparatus includes a radiation system for providing a projection beam of radiation having a wavelength &lgr;1 smaller than 50 nm; a support structure for supporting patterning structure, the patterning structure serving to pattern the projection beam according to a desired pattern; a substrate table for holding a substrate; and a projection system for projecting the patterned beam onto a target portion of the substrate. The apparatus further includes a radiation sensor which is located so as to be able to receive radiation out of the projection beam, said sensor comprising a radiation-sensitive material which converts incident radiation of wavelength &lgr;1 into secondary radiation; and sensing means capable of detecting said secondary radiation emerging from said layer.
Abstract:
A positioning device has first and second object holders that are guided over a guiding surface extending parallel to an X-direction and parallel to a Y-direction perpendicular to the X-direction and which are displaceable over the guiding surface from a first position into a second position by means of a displacement system. The displacement system includes a first displacement unit and a second displacement unit to which the object holders can be alternately coupled. The first displacement unit is suitable for carrying out a first series of positioning steps of the first object holder in the first position and for displacing the first object holder from the first position into an intermediate position between the first and second positions. The second displacement unit is suitable for carrying out a second series of positioning steps of the second object holder in the second position, simultaneously with and independently of the first displacement unit, and for displacing the second object holder from the second position into the intermediate position. In the intermediate position, the object holders are exchanged, after which the first series of positioning steps can be carried out by the first displacement unit with the second object holder in the first position and the second series of positioning steps can be carried out by the second displacement unit with the first object holder in the second position. The positioning device is suitable for use in a lithographic device to carry out an exposure process with a first semiconductor substrate in an exposure position and, simultaneously therewith and independently thereof, a characterization process with a second semiconductor substrate in a characterization position.
Abstract:
A supporting device (53) provided with a first part (69), a second part (71), and a gas spring (73) for supporting the second part relative to the first part parallel to a support direction (Z). The gas spring (73) comprises a pressure chamber (75) which is provided in an intermediate part (79) and is bounded by a piston (81) which is displaceable in the intermediate part (79) parallel to the support direction and is supported perpendicularly to the support direction by means of a static gas bearing (85). A stiffness of the supporting device parallel to the support direction is thus substantially entirely determined by a stiffness of the gas spring, and a low stiffness can be achieved through a suitable design of the gas spring. A transmission of vibrations directed parallel to the support direction from the first part to the second part is prevented as much as possible thereby. The invention also relates to a lithography device having a plurality of such supporting devices.
Abstract:
Systems and methods to protect a mask from being contaminated by airborne particles are described. The systems and methods include providing a reticle secured in a two-part cover. The two part cover includes a removable protection device used to protect the reticle from contaminants. The cover can be held inside a pod or box that can be used to transport the cover through a lithography system from an atmospheric section to a vacuum section. While in the vacuum section, the removable cover can be moved during an exposure process during which a pattern on the reticle can be formed on a wafer.
Abstract:
Systems and methods to protect a mask from being contaminated by airborne particles are described. The systems and methods include providing a reticle secured in a two-part cover. The two part cover includes a removable protection device used to protect the reticle from contaminants. The cover can be held inside a pod or box that can be used to transport the cover through a lithography system from an atmospheric section to a vacuum section. While in the vacuum section, the removable cover can be moved during an exposure process during which a pattern on the reticle can be formed on a wafer.
Abstract:
In an off-axis levelling procedure a height map of the substrate is generated at a measurement station. The height map is referenced to a physical reference surface of the substrate table. The physical reference surface may be a surface in which is inset a transmission image sensor. At the exposure station the height of the physical reference surface is measured and related to the focal plane of the projection lens. The height map can then be used to determine the optimum height and/or tilt of substrate table to position the exposure area on the substrate in best focus during exposure. The same principles can be applied to (reflective) masks.
Abstract:
A position measuring device includes a radiation source mounted on an isolated reference frame and a two-dimensional radiation detector mounted adjacent the radiation source. The object whose position is to be detected has a mirroring device, e.g. a retro-reflector, mounted on it so as to reflect light emitted from the radiation source along a return path that is parallel to but displaced from the incident light path. The amount of displacement is dependent on the position of the object and is measured by the two-dimensional detector. Three such devices can be combined in a system to measure the position of the object in all six degrees of freedom.
Abstract:
An actuator comprises a magnet yoke and a carrier member movable relative to the magnet yoke. The magnet yoke has at least one permanent magnet and the carrier member is positioned in the magnetic field produced by this magnet. The carrier member has an auxiliary magnetic member that produces a relative bias force between the carrier member and the magnet yoke. The bias force will be used to compensate for a weight applied to the device and acts as a bearing with a very large compliance. The carrier member also comprises a coil. Passing current through the coil produces a Lorentz force for further control of the actuator; alternatively, the device provides a velocity transducer by sensing the EMF generated in the coil by relative motion of the carrier member and magnet yoke.
Abstract:
In a lithographic apparatus, a reference grating 11 mounted on the wafer table WT is illuminated with a measurement beam 20 incident in a direction independent of wafer table tilt. The diffraction orders are detected by detector 30 and used to determine the lateral shift in the wafer table resulting from a non-zero Abbe arm, and hence the Abbe arm, for calibration purposes. The detector 30 may be a detector also used for off-axis alignment of the wafer and wafer table.