Vortex via process: analysis and mask fabrication for contact CDs <80 nm

Optical transfer function of an optical system with a vortex phase mask in the presence of primary aberrations

“…In photolithography, wavelength plays an obstacle in patterning small contacts and dense contact arrays with positive photoresist, and attempts to print bright features much smaller than the PSF is not an easy task. However, there is no wavelength corresponding to darkness [30] and the above-mentioned difficulty does not exist in printing of isolated dark spots (centers of these spots correspond to phase singularities). A vortex mask print an array of contact/via holes in a negative resist.…”

“…The central dark core in the point spread function is a unique feature for such a vortex beam. A dark core or doughnut structure is useful in lithography [30,31], microscopy [32,33], and astronomy [34][35][36][37]. Orbital angular momentum arising due to helical phase structure of the beam is also useful in optical manipulation of microparticles [38][39][40].…”

Optimal focusing of a beam in a ring vortex

“…This type of structured field can be useful in several applications, e.g. optical trapping with orbital angular momentum transference [2][3][4], lithography [5,6], high-resolution fluorescence microscopy [7], quantum entanglement [8][9][10], and vortex coronography [11,12].…”

Achromatic optical vortex lens

“…Techniques for creating an optical vortex, 1 which usually require quasi-monochromatic light, restrict these uses. Such applications include optical spatial filtering, 2 optical tweezers, 3 high-resolution fluorescence microscopy, 4 lithography, 5 quantum cryptography, 6 quantum entanglement, 7 infrared vortex polarizers, 8 and stellar coronagraphy. [9][10][11] Additional uses may be possible once the broadband properties of vortices are fully explored.…”