Cymer Laser Technologies

Cymer, Inc.

Donald G Larson

Richard L Sandstrom

Robert P Akins

Uday K Sengupta

Palash P Das

Igor Vladimirovich Fomenkov

Tom A Watson

William N Partlo

Richard C Ujazdowski

Anthony John De Ruyter

Richard G Morton

Thomas Patrick Duffey

Steven Merrill Harrington

Toshihiko Ishihara

Paul S Thompson

I Roger Oliver

Robert A Shannon

Kamal Sarkar

William N Partio

Curtiss Lynn Mixon

Dmitry Berger

James H Azzola

Carl E Tedesco, Ii

Jerry Rudy Gerent

Anthony John deRuyter

A gas discharge laser with fast response gas temperature control to maintain laser gas temperature within desired limits during burst mode operation. Preferred embodiments include a passive temperature stabilizer having fins with surface areas exposed to flowing laser gas at least equal to the surface area of the cooling fins of a laser gas heat exchanger. Preferred embodiments utilize heating elements and coolant flow control to regulate laser gas temperatures using processors programmed to anticipate idle periods.

Gas discharge laser with gas temperature control

Disclosed is a laser useful in, e.g., photolithography or medical surgery. In one embodiment, the laser comprises a discharge chamber and heat-generating electronics that are enclosed in a baffled enclosure that requires less cooling air to reliably cool the components in the enclosure than previous unbaffled enclosures. A method of reducing the amount of conditioned air is also provided. In a further embodiment, the laser has a heat-exchange system that acts quickly in response to changes in laser gas temperature by adjusting a flow-proportioning valve regulating water flow through a heat exchanger, thereby providing a continuously variable rate of heat exchange through the heat exchanger to maintain the lasing gas temperature constant. Methods of providing a laser beam and of improving the uniformity of a laser beam are disclosed, as are photolithography methods utilizing a laser and method of this invention.

Laser having baffled enclosure

A laser system support structure is provided having an independent, kinematically mounted chamber and optics platform. Swivel-type mounts are used to couple the platform at three points to the laser support frame, thereby allowing the platform to remain static while the support frame, via the swivel mounts, deflects around the platform in response to external forces. The independent platform design provides secondary benefits of creating a compartmentalization of laser system components, leading to a modular type design. Each laser system module is mounted to the support structure on an extension rail, to allow removal of the module from the support frame for easy access during servicing.

Stabilized laser platform and module interface

An electric discharge gas laser having a laser cavity in which is contained a laser gas and a fan for circulating the laser gas. The fan is supported by an active magnetic bearing system and driven by a brushless DC motor in which the rotor of the motor and at least two magnetic bearings sealed within the gas environment of the laser cavity and the motor stator and the coils of the bearing magnets are located outside the gas environment.

Excimer laser with magnetic bearings supporting fan

A brushless DC motor with an adjustable timing feature is provided. The timing adjustment allows a specific motor's performance to be optimized by compensating for individual variations both in the characteristics of the rotor position sensors as well as in their locations. The rotor position sensors may be affixed to a heat sink within a portion of the motor housing. To improve the cooling efficiency of the heat sink at least a portion of the motor housing to which the heat sink is thermally coupled is cooled through either active or passive cooling. The rotor position sensors may be enclosed by a structure which improves their thermal and electrical isolation. A means of monitoring and controlling the speed of the motor is also provided.

Blower motor with adjustable timing

Laser having improved beam quality and reduced operating cost

A housing in a laser system encloses a cathode and a displaced anode and gases ionizable and reactive chemically when a voltage pulse produces a cathode-anode electrical discharge. Moving air cools the components (capacitors, thyratron and triggering circuitry) for producing the voltage pulses. The laser gas temperature is continuously regulated at a particular value whether or not there is an electrical discharge. The concentration of one of the gases in the chamber is regulated to values alternately on opposite sides of an optimal value to provide an optimal energy in each chemical reaction of the gases. The gases are recirculated as by a fan driven on a shaft by a pair of motors and are filtered during such recirculation. The shaft speed is regulated at a particular value and the motor currents are regulated to be equal. Any ozone formed in a compartment holding the high voltage terminals is purged by passing a neutral gas (nitrogen) through the compartment to the atmosphere. The neutral gas is passed into the housing through a hose which also holds a high voltage wire in insulated relationship to other electrical components. A collar arrangement at one wire end provides for the introduction of voltage from the collar to the anode of the thyratron with the hose coupled to the housing and grounds the collar with the wire decoupled from the housing. The different high voltage components are sequentially tested for their operability by a system and method unique to this invention.

Excimer laser

An anode and a cathode in a laser are spaced in a first direction. A voltage difference between these members produces an electrical discharge which ionizes gases in the laser to react chemically and produce coherent radiation. First and second tubes made from a dielectric material are spaced in the laser in a second direction transverse (preferably perpendicular) to the first direction. The anode, the cathode and the tubes extend through the laser in a direction transverse (preferably perpendicular) to the first and second directions. The tubes are preferably at least a 99.9% pure polycrystalline aluminum oxide ceramic with traces of other metallic elements than aluminum. Bushings made from a material homogeneous (preferably identical) to the tube material are integral with the tube near the opposite tube ends. First electrical conductors extend through the tubes. Second electrical conductors (preferably resilient) contact (preferably line contact) the external tube surfaces to define capacitors with the first conductors and the tube material. Positioning members movably engage the tube external surfaces near the tube ends in co-operation with the resilient members establishing three (3)- line contacts with the tubes for positioning the tubes precisely in the cavity. When a voltage pulse is applied between the first conductor inside each tube and the conductors on such tube, the resultant corona discharge from the external tube surface produces ultraviolet light which pre-ionizes the gases in the cavity. This facilitates the ionization of the gases in the cavity when an anode-cathode electrical discharge is produced.

Pre-ionizer for a laser

A compact excimer laser, including a housing structure having a plurality of walls forming an internal laser cavity. A gas is located within the laser cavity and with the gas capable of lasing action. A pair of spaced electrodes are located within the laser cavity and form an electrical discharge area between the electrodes for stimulating gas within the discharge area to lasing action in accordance with an electrical discharge between the electrodes. One of the pair of electrodes is located along a central position within the cavity and is grounded to the housing structure. The other of the pair of electrodes is located adjacent to but spaced from one of the walls of the housing structure and with the other electrode mounted on a main insulator member. The main insulator member is formed of ceramic material and is located intermediate to the one wall of the housing and the other electrode but is spaced from the one wall of the housing to have the main insulator member floating relative to the housing structure. The main ceramic insulator member is compressively supported at a central position of the member and extends outward from this central position without any additional support to have the floating main insulator respond to any bending forces within the laser without any constraint other than the central support.

Compact excimer laser

A compact excimer laser, including a housing structure having a plurality of walls forming an internal laser cavity. A gas is located within the laser cavity and with the gas capable of lasing action. A pair of spaced electrodes are located within the laser cavity and form an electrical discharge area between the electrodes for stimulating gas within the discharge area to lasing action in accordance with an electrical discharge between the electrodes. One of the pair of electrodes is located along a central position within the cavity and is grounded to the housing structure. The other of the pair of electrodes is located adjacent to but spaced from one of the walls of the housing structure an with the other electrode mounted on a main insulator member. The main insulator member is formed of ceramic material and is located intermediate to the one wall of the housing and the other electrode but is spaced from the one wall of the housing to have the main insulator member floating relative to the housing structure. The main ceramic insulator member is compressively supported at a central position of the member and extends outward from this central position without any additional support to have the floating main insulator respond to any bending forces within the laser without any constraint other than the central support.

A compact excimer laser, including a housing structure having a plurality of walls forming an internal laser cavity. A gas is located within the laser cavity and with the gas capable of lasing action. A pair of spaced electrodes are located within the laser cavity and form an electrical discharge area between the electrodes for stimulating gas within the discharge area to lasing action in accordance with an electrical discharge between the electrodes. One of the pair of electrodes is located along a central position within the cavity and is grounded to the housing structure. The other of the pair of electrodes is located adjacent to but spaced from one of the walls of the housing structure and with the other electrode mounted on a main insulator member. The main insulator member is formed of ceramic material and is located intermediate to the one wall of the housing and the other electrode but is spaced from the one wall of the housing to have the main insulator member floating relative the housing structure. The main ceramic insulator member is compressively supported at a central position of the member and extends outward from this central position without any additional support to have the floating main insulator respond to any bending forces within the laser without any constraint other than the central support.

Growing community of inventors

San Diego, CA, United States of America

Donald G Larson