AVS 51st International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS+MS-TuA

Paper PS+MS-TuA2
EUV Light Source Development and Debris Mitigation For 45nm Node Lithography and Beyond

Tuesday, November 16, 2004, 1:40 pm, Room 213A

Session: 45nm Node with Panel Discussion
Presenter: B.E. Jurczyk, University of Illinois at Urbana-Champaign
Authors: B.E. Jurczyk, University of Illinois at Urbana-Champaign
M.A. Jaworski, University of Illinois at Urbana-Champaign
M.J. Neumann, University of Illinois at Urbana-Champaign
M.J. Williams, University of Illinois at Urbana-Champaign
D.N. Ruzic, University of Illinois at Urbana-Champaign
Correspondent: Click to Email
Discharge-produced plasma (DPP) light sources are leading candidates for generating 13.5-nm wavelengths needed for next-generation optical lithography. Traditional DPP sources have used xenon radiators due to its cleanliness; however, high output requirements (>115W at first focus) are driving developers towards higher conversion efficiency fuels such as tin. As a result, condensable tin vapor and electrode debris reaching and damaging the first collector optic is a serious concern for device lifetime and cost of ownership. A secondary-plasma debris mitigation technique was successfully demonstrated for noble gas light sources at the Illinois Debris-mitigation EUV Applications Laboratory (IDEAL). The IDEAL facility utilizes a dense plasma focus discharge source operating at nominal conditions of 15 J/pulse, 50 Hz rep rate, and 3 kV. Electrode sputtered debris is re-ionized in a secondary plasma region and removed with a biased foil trap prior to the collection optics. For a low density plasma (10@super 9@ cm@super -3@) condition, a debris removal fraction of 61% ± 3% was observed. The experimental chamber has been modified to operate with tin delivery into the pinch region. Results from electrode redesign, tin injection, EUV light output and condensable tin vapor mitigation will be presented. High density results from an improved internal helical-resonator shielded inductive coil configuration give greater protection efficiency. Fast ions contributing to optic erosion have been observed. Results from a gridded energy analyzer shows two peaked ion distributions at 2.8 keV and 5.8 keV. Elevated plasma potential and sheathing effects have shown an increase in ion energy at the boundaries. An improved ESA/TOF system provides < 5 eV spectral energy resolution and information on charge/mass ratio. Preliminary results from the new Surface Cleaning of Optics by Plasma Exposure (SCOPE) facility are presented for advanced fuel interactions on optical components.