Formation of Nanogap Matrix on Chromium Film by Direct Laser Writing: First Results

Abstract This paper proposes a method for fabricating a nanogap matrix using direct laser writing on chromium films. It has been identified that the nanogap size can be controlled with high repeatability using a photothermal writing mode. As a result, a minimum nanogap width of 180 nm was achieved, which is ⁓1/5 of the incident laser wavelength (780 nm). However, the nanogaps demonstrate a strong depth-width dependence after liquid film development. Initial results indicate good potential for further development of a high-performance methodology for fabricating nanogaps and reducing their width.