Fabrication of nanostencil by size reduction of microaperture by additional deposition

A low-cost method for the fabrication of nanostencils is presented. Microstencils with 1-2-μm-wide patterns were fabricated by standard microelectromechanical systems (MEMS) processes. In order to avoid the use of highly expensive nanolithography tools, the size of microapertures in a stencil was reduced by the subsequent deposition method. The size of microapertures was reduced to the sub-micrometer scale by the additional deposition of SiO ₂. In this study, 500-nm-thick SiO₂ layers were deposited by plasma enhanced chemical vapor deposition (PECVD) on the top surface and bottom surface of a stencil. Deposition on the bottom surface showed a greater size reduction than that on the top surface owing to the taper shape in the cross section of a stencil membrane. The size-reduction rates were 420 nm on the bottom surface, and 290 nm on the top surface when a 500-nm-thick SiO ₂ layer was deposited on a plane. Nanopattering test results using the fabricated nanostencil showed the feasibility of the proposed low-cost nanolithography. An aluminum layer (100nm thick) was deposited through the nanostencil by e-beam evaporation. Nanoscale lines as small as 100nm wide were successfully patterned.