AVS 52nd International Symposium
    Thin Films Monday Sessions
       Session TF+NS-MoA

Paper TF+NS-MoA3
Electron Beam Induced Processing Techniques for Advanced Lithography Mask Repair

Monday, October 31, 2005, 2:40 pm, Room 306

Session: Focused Beam Processing & Fabrication
Presenter: D.A. Smith, University of Tennessee, Knoxville
Authors: D.A. Smith, University of Tennessee, Knoxville
J.D. Fowlkes, University of Tennessee, Knoxville
T. Liang, Intel Corporation
P.D. Rack, University of Tennessee, Knoxville
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Producing defect-free photomasks for semiconductor applications is a critical and challenging operation. Enabling nano-processes are being developed for mask repair to meet the defect requirements for advanced 193nm and EUV lithography. To this end, we are investigating electron beam induced deposition (EBID) and etching (EBIE) techniques for mask repair involving material deposition and removal, respectively. The EUV masks are typically composed of multi-layer Mo-Si on a quartz-like substrate, capped with a Ru etch stop layer with an overlaying TaBN absorber layer. For material removal, an etchant vapor such as XeF2 or NF3 is flowed over the mask surface in an SEM in the presence of an electron beam. The electron beam interacts with the etchant gas to produce an electron induced etch effect, allowing material removal at a controlled rate with nano-scale precision. Repair operations involving deposition are typically carried out with a precursor gas such as cyclopentadienylplatinum (IV)-trimethyl (CpPtMe3) which dissociates under an electron beam and adsorbs to the substrate. This presentation will demonstrate the results of a study involving the optimal operating conditions for controlled etching and deposition, including an analysis of the sidewalls, roughness, and spontaneous etching. Monte-Carlo based computer simulations of the material deposition will also be employed to describe the effects of varying system parameters such as operating voltage, gas pressure, current and time.