JINR Powerful Laser Driver Applied for FEL Photoinjector

Abstract

The JINR develops a project of superconducting linear accelerator complex, based on a superconducting linear accelerator, for applications in nanoindustry, mainly for extreme ultraviolet lithography at a wavelength of 13.5 nm using kW-scale Free Electron Laser (FEL) light source. The application of kW-scale FEL source permits realizing EUV lithography with 22 nm, 16 nm resolutions and beyond. JINR-IAP collaboration constructed powerful laser driver applied for photoinjector of FEL linear accelerator which can be used for EUV lithography. To provide FEL kW-scale EUV radiation the photoinjector laser driver should provide a high macropulse repetition rate of 10 Hz, a long macropulse time duration of 0.8 ms and 8000 pulses per macropulse. The laser driver operates at wavelength of 260-266 nm on forth harmonic in the mode locking on base of Nd ions or Yb ions The laser driver micropulse energy of 1.6 J should provide formation of electron beam in FEL photoinjector with the bunch charge about 1 nC. EUV LITHOGRAPHY BASED ON FEL The project is aimed at construction of accelerator complex, based on a 0.7 GeV superconducting linear accelerator, for applications in nanoindustry, mainly for extreme ultraviolet lithography (EUVL) using kW-scale Free Electron Laser (FEL) light source. The superconducting linear accelerator at electron energy 0.7 GeV will produce coherent FEL radiation for extreme ultraviolet nanolithography at a wavelength of 13.5 nm and an average radiation power of 0.7 kW. Accelerator complex involves a dedicated channel for extreme ultraviolet lithography with a few nanoscanners operating simultaneously in a processing line with 22 nm, 16 nm and beyond using FEL radiation at a wavelength 13.5 nm. The project is based on the technology realized on FEL FLASH (Free Electron Laser in Hamburg) facility at DESY (Hamburg) [1]. FLASH has produced several GW powers for EUV radiation with a wavelength of 13.5 nm, a target goal for the next generation lithography. The driving engine of FLASH facility is an L-band superconducting accelerator [1]. It is designed to operate in a pulsed mode with a pulse duration of 800 microsecond and repetition rate of 10 Hz [1]. The maximum accelerated macropulse current is 10 mA. The present analysis [2-4] shows that this technology holds great potential for increasing the average power of a linear accelerator and the efficiency of conversion of electron kinetic energy into light (Table 1). Table 1: Parameters of EUVL Accelerator Complex and Acceleration complex Electron energy, GeV 0.68