Patterning of Self-Assembled Pentacene Nanolayers by Extreme Ultraviolet-Induced Three-Dimensional Polymerization

Abstract

Most researchers expect extreme ultraviolet lithography (EUVL) to be used to create patterns below 32 nm in semiconductor devices. An ultrathin EUV photoresist (PR) layer a few nanometers thick is required to further reduce the minimum feature size. Here, we show for the first time that pentacene molecular layers can be employed as a new EUV resist. Nanometer-scale dots and lines have been successfully realized using the new molecular resist. We clearly show the mechanism that forms the nanopatterns using a scanning photoemission microscope, EUV interference lithography, an atomic force microscope, and photoemission spectroscopy. The molecular PR has several advantages over traditional polymer EUV PRs. For example, it has high thermal/chemical stability, negligible outgassing, the ability to control the height and width on the nanometer scale, fewer residuals, no need for a chemical development process and thus a reduction of chemical waste when making nanopatterns. Besides, it can be applied to any substrate to which pentacene bonds chemically, such as SiO2, SiN, and SiON, which are important films in the semiconductor device industry.

Hydrophilic/Hydrophobic Film Patterning by Photodegradation of Self-Assembled Alkylsilane Multilayers and Its Applications

“…Practically, a well-ordered monolayer is first deposited by the immersion of a substrate into a dilute organic solution of precursor molecules (thiol, organosilane, or phosphonic acid). Then, a photomask is positioned on top of the SAM-functionalized surface, and subsequent UV irradiation causes either a spatially resolved degradation − or chemical modification − of the monolayer. The numerous benefits of this technique, including ease of use, versatility, high resolution, accurate placement features, and wide exposure field, should not overshadow two major limitations.…”

Chemical, physical and mechanical properties of nanomaterials and its applications

“…Thin films of organic molecules are of great interest as materials for organic lightemitting diodes (OLEDs), transistors (OTFTs), memory devices, and sensors. [293][294][295][296][297][298] Whereas methods to control the compositions and bulk properties of organic thin films typically rely on conventional covalent synthesis to form and modify molecules that comprise a film, 299,300 supramolecular approaches wherein the fabrication and properties of a film are governed by assembly processes involving two or more molecular components have received less attention. 301,302 A recent supramolecular assembly approach to thin films has involved combining block copolymers with small molecules via hydrogen bonds, which has controlled surface porosity and patterning.…”