Abstract: A high repetition rate, compact, modular gas discharge, ultraviolet laser. The laser is useful as a light source for very rapid inspections of wafers in an integrated circuit fabrication process. It is also useful for reticle writing at very rapid rates. A preferred embodiment operates at pulse repetition rates of 1000 to 4000 Hz and is designed for round-the-clock production line operation. This preferred embodiment comprises a pulse control unit which controls the timing of pulses to an accuracy of less than 4 nanoseconds. Preferred embodiments of this gas discharge laser can be configured to operate with a KrF gas mixture, an ArF gas mixture or an F2 gas mixture, each with an approximate buffer gas, producing 248 nm, 197 nm or 157 nm ultraviolet light pulses.

Abstract: A laser discharge unit is provided. The discharge unit includes an elongated electrode plate, an elongated high voltage electrode, and an elongated ground electrode. Both the high voltage electrode and the ground electrode are mounted to the electrode plate in a spaced-apart relationship with their longitudinal axis being substantially parallel to thereby define a gas discharge gap between the electrodes. The gas laser discharge unit may be removably mounted as a module into a gas laser such as an excimer laser.

Abstract: The invention relates to a gas discharge laser including a discharge tube (1), in which a gas is present and which has at least one aperture (19) through which a laser beam emerges or at which a laser beam is reflected. For withdrawing a partial amount of the gas contained in the discharge tube (1), at least one gas withdrawal point (9) is present, from which the withdrawn gas is supplied to a sintered filter (11) for being cleaned. The cleaned gas may be led in via at least one gas inlet point (27) in the zone of the aperture (19). The invention further relates to a method of operating a gas discharge laser, and the use of a sintered filter for cleaning gas withdrawn from a discharge tube (1) of a gas discharge laser.

Abstract: The present invention relates to a gas laser with a high-voltage electrode 12 and a ground electrode 14, which electrodes 12, 14 are disposed relative to each other so as to form a discharge gap 16 between them, and with high voltage generating means including a circuit having at least one storage capacitor and at least one secondary capacitor 18, 20, said secondary capacitor 18, 20 being disposed in the area of said high-voltage electrode 12 within a discharge chamber 32 filled with laser gas. Said secondary capacitor 18, 20 includes at least one external surface 28, 28′ oriented towards said high-voltage electrode 12 and made of a material which is inert with respect to said laser gas, which external surface 28, 28′ forms at least one boundary surface of a flow channel 26, 26′ for said laser gas.

Abstract: A dedusting unit for a laser optical element is provided. The dedusting unit comprises a high-voltage duct comprising a high-voltage conducting core having a first end and a second end and an insulator element disposed around the core. The first end of the core is connectable to a high voltage power supply and the second end of the core is electrically connected to a wire loop. The dedusting unit may be used in connection with a variety of gas lasers. In use, the dedusting unit is mounted to the laser tube so that the wire loop is disposed inside the gas laser tube in proximity to an optical element to be protected from dust. The dedusting unit is further mounted so that the wire loop is transverse to the resonating path of the laser light within the laser tube so that the resonating laser light may pass through the wire loop without being obstructed by the wire loop. A method for installing the dedusting unit to protect a laser optical element in a gas laser is also provided.

Abstract: The present invention relates to an excimer laser comprising a charging circuit including a parallel connection of a storage capacitor (CB) with a series connection of a reoscillation inductance (LB), a charging inductance (LL) and a firing device (Z) for firing the excimer laser, wherein the storage capacitor (CB) has at least a terminal for connecting a power supply (UL), a peaking capacitor (CP) connected in parallel with the charging inductance (LL), a discharge path including two opposed electrodes (E1, E2), connected in parallel with the peaking capacitor (CP), and a driving device for driving the firing device (Z), wherein the firing device (Z) is formed as a MOSFET array. The invention also relates to a corresponding method of operating such an excimer laser.

Abstract: A high repetition rate, compact, modular gas discharge, ultraviolet laser. The laser is useful as a light source for very rapid inspections of wafers in an integrated circuit fabrication process. It is also useful for reticle writing at very rapid rates. A preferred embodiment operates at pulse repetition rates of 1000 to 4000 Hz and is designed for round-the-clock production line operation. This preferred embodiment comprises a pulse control unit which controls the timing of pulses to an accuracy of less than 4 nanoseconds. Preferred embodiments of this gas discharge laser can be configured to operate with a KrF gas mixture, an ArF gas mixture or an F2 gas mixture, each with an approximate buffer gas, producing 248 nm, 197 nm or 157 nm ultraviolet light pulses.

Abstract: A high repetition rate, compact, modular gas discharge, ultraviolet laser. The laser is useful as a light source for very rapid inspections of wafers in an integrated circuit fabrication process. It is also useful for reticle writing at very rapid rates. A preferred embodiment operates at pulse repetition rates of 1000 to 4000 Hz and is designed for round-the-clock production line operation. This preferred embodiment comprises a pulse control unit which controls the timing of pulses to an accuracy of less than 4 nanoseconds. Preferred embodiments of this gas discharge laser can be configured to operate with a KrF gas mixture, an ArF gas mixture or an F2 gas mixture, each with an approximate buffer gas, producing 248 nm, 197 nm or 157 nm ultraviolet light pulses.

Abstract: A gas laser and a dedusting unit thereof are provided. The gas laser comprises a tube containing a gas mixture including a laser gas and preferably a buffer gas. The tube preferably comprises a cylindrical inner wall. A discharge unit is inserted into the tube and has two elongated electrodes defining an electrical gas discharge gap therebetween for providing an electric gas discharge between said electrodes to generate laser light. A circulation means is included in the tube for generating a gas flow within the tube that passes through the discharge gap. A dedusting unit is mounted along the inner cylindrical wall of the tube in such a manner that only a bypass flow which is a part of the gas flow within the tube passes through the dedusting unit.

Abstract: The invention relates to a gas discharge laser including a discharge tube (1), in which a gas is present and which has at least one aperture (19) through which a laser beam emerges or at which a laser beam is reflected. For withdrawing a partial amount of the gas contained in the discharge tube (1), at least one gas withdrawal point (9) is present, from which the withdrawn gas is supplied to a sintered filter (11) for being cleaned. The cleaned gas may be led in via at least one gas inlet point (27) in the zone of the aperture (19). The invention further relates to a method of operating a gas discharge laser, and the use of a sintered filter for cleaning gas withdrawn from a discharge tube (1) of a gas discharge laser.

Abstract: A gas laser discharge unit is provided. The discharge unit includes an elongated electrode plate having a plurality of spaced-apart holes therein and a plurality of coaxial high voltage ducts. Each duct extends through one of the holes in the electrode plate and includes a central conductive core and an insulator element arranged around the core to electrically insulate said core from the electrode plate. An elongated high voltage electrode is electrically connected to the cores of the ducts. In addition, an elongated ground electrode is positioned to oppose the high voltage electrode and form a gas discharge gap therebetween. The ground electrode is electrically connected to the electrode plate. The gas laser discharge unit may be removably mounted as a module into a gas laser tube, such as an excimer laser tube.

Abstract: The present invention relates to a gas laser with a high-voltage electrode 12 and a ground electrode 14, which electrodes 12, 14 are disposed relative to each other so as to form a discharge gap 16 between them, and with high voltage generating means including a circuit having at least one storage capacitor and at least one secondary capacitor 18, 20, said secondary capacitor 18, 20 being disposed in the area of said high-voltage electrode 12 within a discharge chamber 32 filled with laser gas. Said secondary capacitor 18, 20 includes at least one external surface 28, 28′ oriented towards said high-voltage electrode 12 and made of a material which is inert with respect to said laser gas, which external surface 28, 28′ forms at least one boundary surface of a flow channel 26, 26′ for said laser gas.

Abstract: An adjustable mounting unit for an optical element of a gas laser is provided. The typical gas laser for which the mounting unit will be used comprises a tube having a first end wall at one end and a second end wall at the other end, an optical axis extending longitudinally through the tube, and a port in the first end wall through which the optical axis passes. The mounting unit includes a rigid support structure having an aperture therein and an optical element mounted within the aperture. In addition, at least three adjustable mounting devices are used to attach the support structure to the laser tube. The mounting points are preferably selected so that they are displaced in an axial direction by substantially the same amount due to dimensional changes in the laser occurring during operation of the laser. When attached to the laser, the rigid support is spaced apart from the laser tube to allow for the adjustment of the angular positioning of the optical element.

Abstract: An electrode arrangement for a gas laser is provided. The electrode arrangement includes an elongated high voltage electrode, an elongated ground electrode disposed adjacent to the high voltage electrode, a discharge gap between the two electrodes an insulator element, a high voltage conductor having a first end connected to the high voltage electrode and extending through the insulator element, and a shadow plate interposed between the discharge gap and the insulator element. The electrode arrangement may be employed in a variety of gas lasers, including excimer lasers.

Abstract: The present invention relates to an excimer laser comprising a charging circuit including a parallel connection of a storage capacitor (CB) with a series connection of a reoscillation inductance (LB), a charging inductance (LL) and a firing device (Z) for firing the excimer laser, wherein the storage capacitor (CB) has at least a terminal for connecting a power supply (UL), a peaking capacitor (Cp) connected in parallel with the charging inductance (LL), a discharge path including two opposed electrodes (E1, E2), connected in parallel with the peaking capacitor (Cp), and a driving device for driving the firing device (Z), wherein the firing device (Z) is formed as a MOSFET array. The invention also relates to a corresponding method of operating such an excimer laser.

Abstract: A high repetition rate, compact, modular gas discharge, ultraviolet laser. The laser is useful as a light source for very rapid inspections of wafers in an integrated circuit fabrication process. It is also useful for reticle writing at very rapid rates. A preferred embodiment operates at pulse repetition rates of 1000 to 4000 Hz and is designed for round-the-clock production line operation. This preferred embodiment comprises a pulse control unit which controls the timing of pulses to an accuracy of less than 4 nanoseconds. Preferred embodiments of this gas discharge laser can be configured to operate with a KrF gas mixture, an ArF gas mixture or an F2 gas mixture, each with an approximate buffer gas, producing 248 nm, 197 nm or 157 nm ultraviolet light pulses.