A lithographic apparatus configured to project a patterned beam of radiation onto a target portion of a substrate is disclosed. The apparatus includes a first radiation dose detector and a second radiation dose detector, each detector comprising a secondary electron emission surface configured to receive a radiation flux and to emit secondary electrons due to the receipt of the radiation flux, the first radiation dose detector located upstream with respect to the second radiation dose detector viewed with respect to a direction of radiation transmission, and a meter, connected to each detector, to detect a current or voltage resulting from the secondary electron emission from the respective electron emission surface.

Lithographic apparatus, and device manufacturing method

Extreme ultraviolet lithography (EUVL) was thoroughly reviewed over a broad range of topics, including history, tools, source, metrology, condenser and projection optics, resists, and masks. Since 1988, many studies on EUVL have been conducted in North America, Europe, and Japan, through state sponsored programs and industrial consortiums. To date, no “show stopper” has been identified, but challenges are present in almost all aspects of EUVL technology. Commercial alpha lithography step-and-scan tools are installed with full-field capability; however, EUVL power at intermediate focus (IF) has not yet met volume manufacturing requirements. Compared with the target of 180W IF power, current tools can supply only approximately 55–62W. EUV IF power has been improved gradually from xenon- to tin-discharge-produced plasma or laser-produced plasma. EUVL resist has improved significantly in the last few years, with 25nm 1:1 line/space resolution being produced with approximately 2.7nm (3σ) line edge roughness. A...

Extreme ultraviolet lithography: A review

The present invention provides a reliable, high-repetition rate, production line compatible high energy photon source. A very hot plasma containing an active material is produced in vacuum chamber. The active material is an atomic element having an emission line within a desired extreme ultraviolet (EUV) range. A pulse power source comprising a charging capacitor and a magnetic compression circuit comprising a pulse transformer, provides electrical pulses having sufficient energy and electrical potential sufficient to produce the EUV light at an intermediate focus at rates in excess of 5 Watts. In preferred embodiments designed by Applicants in-band, EUV light energy at the intermediate focus is 45 Watts extendable to 105.8 Watts.

Extreme ultraviolet light source

Recent advances in solid-state semiconductors have led to the development of medium-voltage power converters (e.g., 6-36 kV) which could obviate the need for the step-up transformers of renewable power generation systems. The modular multilevel cascaded converters have been deemed as strong contenders for the development of medium-voltage converters, but the converters require multiple isolated and balanced dc supplies. In this paper, a high-frequency link multilevel cascaded medium-voltage converter is proposed. The common high-frequency link generates multiple isolated and balanced dc supplies for the converter, which inherently minimizes the voltage imbalance and common mode issues. An 11-kV system is designed and analyzed taking into account the specified system performance, control complexity, cost, and market availability of the power semiconductors. To verify the feasibility of the proposed system, a scaled down 1.73-kVA laboratory prototype test platform with a modular five-level cascaded converter is developed and explored in this paper, which converts a 210 V dc (rectified generator voltage) into three-phase 1 kV rms 50 Hz ac. The experimental results are analyzed and discussed. It is expected that the proposed new technology will have great potential for future renewable generation systems and smart grid applications.

A High-Frequency Link Multilevel Cascaded Medium-Voltage Converter for Direct Grid Integration of Renewable Energy Systems

An extreme ultraviolet light source apparatus has a magnetic field generator which generates a magnetic field region around a direction of the magnetic field passing through a plasma region in which a plasma is to be generated and converges charged particles including ion emitted from the plasma region toward the direction of the magnetic field, a first charged particle collector (receiver) mounted at both sides of an axis of the magnetic field in the magnetic field region in order to collect (receive) the charged particles converged by the magnetic field, a target supply unit supplying a target from a nozzle located outside a converging region in which the charged particles are to be converged inside the magnetic field region in an extreme ultraviolet light generating chamber, and a target collector located at a position opposite to the nozzle, the target retrieval portion retrieving a residual target which does not contribute to generation of the plasma.

Extreme ultraviolet light source apparatus

An injection seeded modular gas discharge laser system (2) capable of producing high quality pulsed beams at pulse rates of about 4,000 Hz or greater and at pulse energies of about 5 mJ or greater. Two separate discharge chambers are provided, one of which is a part of a master oscillator (10) producing a very narrow band seed beam, which is amplified (12) in the second discharge chamber. The chambers can be controlled separately permitting separate optimization of wavelength parameters in the master oscillator and optimization of pulse energy parameters in the amplifying chamber. A preferred embodiment in the ArF excimer laser system configured as a MOPA and specifically designed for use as a light source for integrated circuit lithography. In the preferred MOPA embodiment, each chamber comprises a single tangential fan (10A) providing sufficient gas flow to permit operation at pulse rates of 4,000 Hz or greater by cleaning debris from the discharge region in less time that the approximately 0.25 milliseconds between pulses. The masters oscillation is equipped with a line narrowing package having a very fast tuning mirror capable of controlling centerline wavelength on a pulse-to-pulse basis at repetition rates of 4000 Hz or greater to a precision of less than 0.2 pm.

Very narrow band, two chamber, high rep rate gas discharge laser system

The present invention provides a reliable modular production quality excimer laser capable of producing 10 mJ laser pulses in the range of 1000 Hz to 2000 Hz or greater. Replaceable modules include a laser chamber (211); a pulse power system comprised of three modules; an optical resonator comprised of a line narrowing module (206) and an output coupler module (216); a wavemeter module (213), an electrical control module (205), a cooling water module (203) and a gas control module (202). Improvements in the pulse power unit to produce faster rise time and improved pulse energy control include: sn increased capacity high voltage power supply with a voltage bleed-down circuit for precise voltage trimming, an improved commutation module (209) that generates a high voltage pulse from the capacitors charged by the high voltage power supply (20) and amplifies the pulse voltage 23 times with a very fast voltage transformer having a secondary winding consisting of a single four-segment stainless steel rod. The compression head (207) saturable inductor greatly reduces the quantity of oil required and virtually eliminates the possibility of oil leakage.

Reliable, modular, production quality narrow-band high rep rate F2 laser

The present invention provides a high energy photon source. A pair of plasma pinch electrodes are located in a vacuum chamber. The chamber contains a working gas which includes a noble buffer gas and an active gas chosen to provide a desired spectral line. A pulse power source provides electrical pulses at voltages high enough to create electrical discharges between the electrodes to produce very high temperature, high density plasma pinches in the working gas providing radiation at the spectral line of the source or active gas. Preferably the electrodes are configured co-axially. The central electrode is preferably hollow and the active gas is introduced out of the hollow electrode. This permits an optimization of the spectral line source and a separate optimization of the buffer gas. In preferred embodiments the central electrode is pulsed with a high negative electrical pulse so that the central electrode functions as a hollow cathode. Preferred embodiments present optimization of capacitance values, anode length and shape and preferred active gas delivery systems are disclosed. Preferred embodiments also include a pulse power system comprising a charging capacitor and a magnetic compression circuit comprising a pulse transformer. Special techniques are described for cooling the central electrode. In one example, water is circulated through the walls of the hollow electrode. In another example, a heat pipe cooling system is described for cooling the central electrode.

Plasma focus light source with improved pulse power system

The present invention provides a reliable modular production quality excimer laser capable of producing 10 mJ laser pulses at 2000 Hz with a full width half, maximum bandwidth of about 0.6 pm or less. Replaceable modules include a laser chamber; a pulse power system comprised of three modules; an optical resonator comprised of a line narrowing module and an output coupler module; a wavemeter module, an electrical control module, a cooling water module and a gas control module. Improvements in the laser chamber permitting the higher pulse rates and improved bandwidth performance include a single upstream preionizer tube and a high efficiency chamber. The chamber is designed for operation at lower fluorine concentration. Important improvements have been provided in the pulse power unit to produce faster rise time and improved pulse energy control. These improvements include an increased capacity high voltage power supply with a voltage bleed-down circuit for precise voltage trimming, an improved commutation module that generates a high voltage pulse from the capacitors charged by the high voltage power supply and amplifies the pulse voltage 23 times with a very fast voltage transformer having a secondary winding consisting of a single four-segment stainless steel rod. A novel design for the compression head saturable inductor greatly reduces the quantity of transformer oil required and virtually eliminates the possibility of oil leakage which in the past has posed a hazard.

Richard M. Ness

Papers

Extreme ultraviolet light source

Very narrow band, two chamber, high rep rate gas discharge laser system

Reliable, modular, production quality narrow-band high rep rate F2 laser

Plasma focus light source with improved pulse power system

Reliable, modular, production quality narrow-band high rep rate ArF excimer laser