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Atomic hydrogen dry etching was used for microstructure fabrication. Photolithography was proposed and achieved by a dry development process using atomic hydrogen irradiation. The reaction system of poly(methyl methacrylate) mixed with molecular benzophenone was examined as a model system for a proof-of-concept study. Optical patterning was experimentally made on a thin layer of poly(methyl methacrylate) with benzophenone by UV light exposure with a photomask. The reaction system acted as a negative tone resist in the proposed process. Thus, a model system for a new atomic hydrogen dry development process was proposed and successfully demonstrated. [ABSTRACT FROM AUTHOR]

In this paper, we investigated the removal characteristic of positive-tone novolak photoresists into which B, P. and As ions were implanted with doses of 5 x 1012-5 x 1015 atoms/cm2 at an acceleration energy of 70 keV using atomic hydrogen, and the hardening mechanisms for the photoresists. All of the ion-implanted photoresists with doses up to 5 x 1015 atoms/cm2 were removed without regard for ion species. The removal rates of the photoresists decreased with increasing ion-implantation dose due to hardening of the photoresist surfaces with implantation. The thickness of the surface-hardened layer of the photoresists decreased in the order of B → P → As, and the removal rate increased with decreasing thickness. The energy supplied from the ions to the photoresist concentrated on the surface side in the order of B → P → As, and the impact of the heavier ion on the photoresist was greater than that of the lighter ion. We deduced that the photoresists exhibited carbonization and cross-linkage attributable to the decrease in OH, CH, and 0 Is and the increase in C=C, C is, and if-conjugated systems. [ABSTRACT FROM AUTHOR]

Mass spectrometry was used to identify the decomposition products of two typical photoresist polymers, Novolak and polymethylmethacrylate, by H atoms produced on hot wire surfaces. The production of CH 4 and CO was confirmed for both polymers. Other possible products are C 3 H 8 , C 4 H 10 or C 4 H 8 , and some esters such as CH 3 COOC 2 H 5 . The production of CO 2 , C 2 H 4 , C 2 H 6 , alcohols, and aromatics are minor. The possible decomposition mechanisms are discussed on the basis of density functional calculations of the energetics. [ABSTRACT FROM AUTHOR]