The Optimal Conditions Reasearch Of Extreme Ultraviolet Emission Source From Xe Plasma Produced By 3mm Diameter Capillary Discharge

Extreme Ultraviolet (EUV) Lithography is the leading technology for patterning at the 32nm technology node and beyond. It uses the wavelength of 13.5 nm extreme-ultraviolet emission as exposure light. In this paper, we use 3mm diameter capillary discharge with Xe gas to produce strong 13.5nm (2% bandwidth) radiation. Through changing the different discharge manner, Xe flow rate and the amplitude of main pulse current, we find the optimal conditions of achieving in-band 13.5nm radiation output in present experiment device. It is beneficial to conduct the study with smaller diameter capillary in future.First of all, we use snowplow model to describe the Z-pinch theory and analyze the pinch process of Xe plasma through numerical simulations in combination withexperiments. Through comparing the moment of EUV peak intensity measured in the experiment with simulated relationship between the plasma Z-pinch diameter and time, we confirm the existence of plasma multiple pinch process. Meanwhile the paper studies the influence of plasma axial pinch process caused by varying the amplitude of current and Xe flow rate, provides some reference on the choice of discharge parameters.Chapter 3 introduces the EUV source system detailly and illustrates its main component and function. With these experiment devices, we get the ultraviolet radiation spectrum and analysis the intense EUV emission spectrum within the 10¹7nm wavelength range. Finally we find the 13.5nm radiation in the spectrum and the spectral line corresponding to Xe ions ranging from Xe^7+Xe¹²⁺We studies the influence of in-band 13.5nm radiation intensity caused by changing the amplitude of current, Xe flow rate and injecting xenon-helium mixtures. Results of the in-band EUV measurements around 13.5nm shows that the higher the currentamplitude and lower Xe gas flow rate lead to higher intensity of EUV radiation around 13.5nm (2% bandwidth) in our lab. Meanwhile it is found that higher in-band 13.5nm intensity is obtainable from moderate xenon-helium mixtures than pure xenon. However, the plasma electronic temperature will drop and affect the intensity of in-band 13.5nm radiation when injecting excess helium gas. Then we study the relationship between , which is to lay the foundation for finding the optimal conditions of in-band 13.5nm radiation output later. in-band 13.5nm radiation intensity and Xe gas flow rate from xenon/helium mixtures, the analysis results show that the radiation intensity peak when Xe flow rate is 0.7sccm.Finally, we summary experimental results and get the best condition to achieve in-band radiation in this system.