AVS 56th International Symposium & Exhibition
    Plasma Science and Technology Tuesday Sessions
       Session PS-TuP

Paper PS-TuP5
Infinitely High Selective Etching of ITO Binary Mask Structure for Extreme Ultraviolet Lithography (EUVL)

Tuesday, November 10, 2009, 6:00 pm, Room Hall 3

Session: Plasma Science and Technology Poster Session
Presenter: N.-E. Lee, Sungkyunkwan University, Korea
Authors: Y.R. Park, Sungkyunkwan University, Korea
N.-E. Lee, Sungkyunkwan University, Korea
Correspondent: Click to Email
Currently, extreme ultraviolet lithography (EUVL) is being investigated for next generation lithography. Among the core extreme ultraviolet lithography (EUVL) technologies, mask fabrication for EUVL is of considerable importance due to the use of new reflective optics having a completely different configuration compared to those of conventional photolithography. This study investigated the etching properties of EUVL binary mask structure including newly proposed absorber layer of ITO, Ru (capping/etch-stop layer), and Mo-Si multilayer (reflective layer) by varying the gas flow ratio, dc self-bias voltage (Vdc) and etch time in Cl2/Ar inductively coupled plasmas. ITO absorber layer needs to be etched with no loss of Ru layer on the Mo-Si multilayer for fabrication of the EUVL ITO binary mask structure proposed here. The ITO layer could be etched with an infinitely high etch selectivity over Ru etch-stop layer in Cl2/Ar plasmas with Vdc of -50 V even with increasing over etch time. Etching of the stacked mask structures with a 200-nm line/space e-beam resist pattern showed a vertical profile and an etch-stop on the Ru etch-stop layer.