FABRICATION OF SUB-30 NM MASKS FOR X-RAY NANOLITHOGRAPHY

For the study of the ultimate resolution limits of x-ray nanolithograp hy, i.e., the contact printing of features smaller than 30 n m, the bi ggest task is the production of x-ray nanomasks. The fabrication of su ch conventional masks with features as small as 12 nm for isolated dot s and 25 nm for isolated lines is reported. High-energy electron beam lithography, using a transmission electron microscope operating at a v oltage of 200 kV was carried out in a 400-nm-thick single resist layer with an electron probe of 1 nn in diameter. The ability of gold plati ng to enter very narrow structures is demonstrated here: 12 nm width a bsorber features with a thickness of 360 nm are obtained. We demonstra te that sub-30 nm features can be routinely produced with aspect ratio s as high as 15 with a good process latitude. (C) 1995 American Vacuum Society.