Design considerations of 10 kW-scale extreme ultraviolet SASE FEL for lithography

The semiconductor industry growth is driven to a large extent by steady advancements in microlithography. According to the newly updated industry roadmap, the 70 nm generation is anticipated to be available in the year 2008. However, the path to get there is not obvious. The problem of construction of extreme ultraviolet (EUV) quantum laser for lithography is still unsolved: progress in this field is rather moderate and we can not expect a significant breakthrough in the near future. Nevertheless, there is clear path for optical lithography to take us to sub-100 nm dimensions. Theoretical and experimental work in self-amplified spontaneous emission (SASE) free electron lasers (FEL) physics, and the physics of superconducting linear accelerators over the last ten years has pointed to possibility of the generation high-power optical beams with laser-like characteristics in the EUV spectral range. Recently there have been important advance in demonstrating a high-gain SASA FEL at 100 nm wavelength [1]. The SASE FEL concept eliminates the need for an optical cavity. As a result, there are no apparent limitations which would prevent operation at very short wavelength range and to increase the average output power of this device up to 10-kW level. The use of superconducting energy-recovery linac could produce a major, cost-effective facility with wall plug power to output optical power efficiency of about 1%. A 10-kW scale transversely coherent radiation source with narrow bandwidth (0.5%) and variable wavelength could be excellent tool for manufacturing computer chips with the minimum feature size below 100 nm. All components of the proposed SASE FEL equipment (injector, driver accelerator structure, energy recovery system, undulator etc.) have been demonstrated in practice. This is guaranteed success in the time schedule requirement. (orig.)SIGLEAvailable from TIB Hannover: RA 2999(00-115) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Design considerations of a MW-scale, high-efficiency, industrial-use, ultraviolet FEL amplifier

Theoretical and experimental work in free electron laser (FEL) physics, and the physics of particle accelerators over the last ten years has pointed to the possibility of the generation of MW-level optical beams with laser-like characteristics in the ultraviolet (UV) spectral range. The concept is based on generation of the radiation in the master oscillator - power FEL amplifier (MOPA) configuration. The FEL amplifier concept eliminates the need for an optical cavity. As a result, there are no thermal loading limitations to increase the average output power of this device up to the MW-level. The problem of a tunable master oscillator can be solved with available conventional quantum lasers. The use of a superconducting energy-recovery linac could produce a major, cost-effective facility with wall plug power to output optical power efficiency of about 20 per cent that spans wavelengths from the visible to the deep ultraviolet regime. The stringent electron beam qualities required for UV FEL amplifier operation can be met with a conservative injector design (using a conventional thermionic gun and subharmonic bunchers) and the beam compression and linear acceleration technology, recently developed in connection with high-energy linear collider and X-ray FEL programs. (orig.)53 refs.Available from TIB Hannover: RA 2999(00-015) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman