Recent Progress in EUV Metal Oxide Photoresists

Kasahara, Kazuki; Xu, Hong; Kosma, Vasiliki; Odent, Jérémy; Giannelis, Emmanuel P.; Ober, Christopher K.

doi:10.2494/photopolymer.30.93

Cited by 9 publications

(6 citation statements)

References 10 publications

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“…To circumvent the challenges posed by conventional resist materials, efforts have recently begun focusing on a new class of materials, hybrid inorganic–organic clusters, composed of an inorganic metal or metal oxide core or nanoparticle capped with organic ligands. − These systems, first developed at Cornell University, possess properties that are inherently amenable to EUV patterning, such as comparatively strong EUV absorption from its inorganic core, high etch resistance, and the ability to tailor their chemistry through tunable ligand terminations. One such system that has demonstrated high sensitivity for negative-tone patterning consists of a hafnium oxide core capped with methacrylic acid (MAA) ligands (HfMAA).…”

Section: Introductionmentioning

confidence: 99%

Chemical Modification Mechanisms in Hybrid Hafnium Oxo-methacrylate Nanocluster Photoresists for Extreme Ultraviolet Patterning

et al. 2018

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The potential implementation of extreme ultraviolet (EUV) lithography into next generation device processing is bringing urgency to identify resist materials that optimize EUV lithographic performance. Inorganic/organic hybrid nanoparticles or clusters constitute a promising new class of materials, with high EUV sensitivity from the core and tunable chemistry through the coordinating ligands. Development of a thorough mechanistic understanding of the solubility switching reactions in these materials is an essential first step toward their implementation in patterning applications but remains challenging due to the complexity of their structures, limitations in EUV sources, and lack of rigorous in situ characterization. Here we report a mechanistic investigation of the solubility switching reactions in hybrid clusters comprised of a small HfOx core capped with a methacrylic acid ligand shell (HfMAA). We show that EUV-induced reactions can be studied by performing in situ IR spectroscopy of electronirradiated films using a variable energy electron gun. Combining additional ex situ metrology, we track the chemical evolution of the material at each stage of a typical resist processing sequence. For instance, we find that a crosslinking reaction initiated by decarboxylation of the methacrylate ligands under electron irradiation constitutes the main solubility switching mechanism, although there are also chemical changes imparted by a typical the post application bake (PAB) step alone. Lastly, synchrotronbased IR microspectroscopy measurements of EUV-irradiated HfMAA films enable a comparison of reactions induced by EUV vs electron beam irradiation of the same resist material, yielding important insight into the use of electron beam irradiation as an experimental model for EUV exposure.

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Section: Introductionmentioning

confidence: 99%

Chemical Modification Mechanisms in Hybrid Hafnium Oxo-methacrylate Nanocluster Photoresists for Extreme Ultraviolet Patterning

et al. 2018

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“…Metal-oxide-based resist with organic ligands show immense potential for EUV lithography owing to their higher absorption cross section at 92 eV as well as higher etch resistance [9]. In this work, we report a PES study on tin-based open-source metal oxide (OSMO) model photoresist.…”

Section: Osmo Photoelectron Spectrummentioning

confidence: 99%

Actinic photoemission spectroscopy of litho materials using a table-top ultrafast EUV source

Singh,

Dorney,

Holzmeier

et al. 2024

Metrology, Inspection, and Process Control XXXVIII

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Extreme ultraviolet (EUV) lithography (92 eV) has recently entered logic and memory high-volume manufacturing to ensure the continuation of Moore's Law into advanced technology nodes (sub 5 nm). In parallel to advancements in the lithographic system, the development of suitable photoresists plays an equally important role in pushing the boundaries of EUV lithography. Fundamental work on well-established chemically amplified resists (CAR) for EUV as well as the upcoming resists based on metal-organic materials have indicated that the lithographic mechanism is largely governed by electron mediated chemistry. In a simplified model, the electrons emitted upon ionization of the material generate further secondary electrons, which interact with the resist components and induce a solubility switch driven by electron and radiation chemistry. To develop a better performing resist, it is of utmost importance to understand the photoelectron kinetic energy spectrum, secondary electrons and their generation efficiency, and the electron mean free path in the photoemission process. In this work, we use photoemission spectroscopy with a table-top, coherent, 92 eV photon source to shed light on the chemistry driven by photon exposure. The valence band photoelectron spectrum (PES) of an environmentally stable chemically amplified photoresist (ESCAP), as well as a model material for an open-source metal oxide (OSMO) resist were measured using our tabletop EUV photoemission setup. We report the evolution of the PES as a function of exposure dose; capturing chemical changes.

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“…Although appropriate line patterns with a 24 nm width and 120 nm pitch are realized, the resolution and line-edge roughness need to be further improved (i.e. material reaction mechanisms to EUV light and environment are known to cause changes in material dissolution properties in developer solution, which is a factor in improving pattern quality 12) ). Understanding the reaction mechanism of the metal resists is indispensable for further improvements.…”

Section: Introductionmentioning

confidence: 99%

Reaction mechanism of ZrO _x metal resists with extreme ultraviolet irradiation

Yamashita

Chikyow

Santillan

et al. 2019

Jpn. J. Appl. Phys.

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The reaction mechanism of ZrO-based metal resists by extreme ultraviolet (EUV) exposure was investigated using hard X-ray photoelectron spectroscopy, near edge X-ray absorption fine structure spectroscopy, and X-ray diffraction. EUV exposure did not affect the amorphous structure of the metal resist. After EUV exposure, the π* states of the C atom and the σ* states of the O atom of the cell molecules were reacted. Moreover, EUV exposure decomposed the carbonyl species of the cell molecules and forms the high oxidation states of ZrO x . Thus, the metal resist reaction occurred with the decomposition of cell molecules and the formation of ZrO 2 by EUV exposure.

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Recent Progress in EUV Metal Oxide Photoresists

Cited by 9 publications

References 10 publications

Chemical Modification Mechanisms in Hybrid Hafnium Oxo-methacrylate Nanocluster Photoresists for Extreme Ultraviolet Patterning

Chemical Modification Mechanisms in Hybrid Hafnium Oxo-methacrylate Nanocluster Photoresists for Extreme Ultraviolet Patterning

Actinic photoemission spectroscopy of litho materials using a table-top ultrafast EUV source

Reaction mechanism of ZrO _x metal resists with extreme ultraviolet irradiation

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Recent Progress in EUV Metal Oxide Photoresists

Cited by 9 publications

References 10 publications

Chemical Modification Mechanisms in Hybrid Hafnium Oxo-methacrylate Nanocluster Photoresists for Extreme Ultraviolet Patterning

Chemical Modification Mechanisms in Hybrid Hafnium Oxo-methacrylate Nanocluster Photoresists for Extreme Ultraviolet Patterning

Actinic photoemission spectroscopy of litho materials using a table-top ultrafast EUV source

Reaction mechanism of ZrO x metal resists with extreme ultraviolet irradiation

Contact Info

Product

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Reaction mechanism of ZrO _x metal resists with extreme ultraviolet irradiation