Projection x-ray lithography with ultrathin imaging layers and selective electroless metallization

Proximity X-ray Lithography Using Self-Assembled Alkylsiloxane Films: Resolution and Pattern Transfer

“…Features with dimensions as small as 70 nm (limited by the availability of X-ray masks) were successfully printed on the SA films. The current work demonstrates a substantial increase in resolution compared to previous reports in which self-assembled monolayers (SAMs) of alkylsiloxanes were patterned with parallel processes such as deep ultraviolet projection lithography (features of ∼400 nm) 4 and X-ray lithography (features of ∼250 nm) . Better resolution is due in part to our increased knowledge of the chemical modification of SAMs of alkylsiloxanes upon exposure to high-energy photons in the presence of oxygen.…”

“…We and others have previously demonstrated that siloxane films can be molecularly engineered to be highly sensitive to various types of radiation, including deep UV, , e-beam, − ion beam, X-ray, , low energy electrons, and the low energy electrons from a STM or the electric field from a conducting atomic force microscopy (AFM) tip. − Organosiloxane films, of monolayer thickness, can be particularly effective imaging layers when used in conjunction with high-energy exposure tools because their use avoids depth-of-focus and transparency issues generally associated with conventional thick (i.e., ∼1 μm) photoresist polymer films. For example, recently we demonstrated that siloxane films bearing benzyl chloride functional groups were photooxidized upon exposure to proximity X-rays .…”

Photochemistry and Patterning of Self-Assembled Monolayer Films Containing Aromatic Hydrocarbon Functional Groups

“…We have previously shown that organosilane SAM films are sensitive to, and can be patterned with, various forms of radiation, including deep UV, − ,− soft X-rays, , ions, , and electrons. , Upon irradiation, properties such as the wettability or reactivity of a film are modified, to an extent controlled by the dose delivered to the surface. Patterned irradiation of organosilane SAMs may be used to create laterally modulated patterns of chemical functionality on a surface.…”

Fabrication of Patterned Amine Reactivity Templates Using 4-Chloromethylphenylsiloxane Self-Assembled Monolayer Films

“…Recent work has shown that surface reactivity templates can be fabricated by microcontact-printing processes, in which organosilanes are directly deposited for chemisorption at predetermined sites on a hydroxyl-bearing surface using a stamp. More often, however, a homogeneous organosiloxane SAM is patterned using either direct write processes involving exposure sources such as electron beams, ion beams, and proximal probes or conventional masked-based photolithographic processes using UV , or extreme ultraviolet (EUV) exposure sources. The templates formed are subsequently chemically reacted in one or more steps to covalently bind a species of interest to the film.…”