EUV metal oxide hybrid photoresists: ultra-small structures for high-resolution patterning

Xu, Hong; Yang, Kejian; Sakai, Kazunori; Kosma, Vasiliki; Kasahara, Kazuki; Giannelis, Emmanuel P.; Ober, Christopher K.

doi:10.1117/12.2297266

Cited by 3 publications

(6 citation statements)

References 6 publications

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“…17 These performance targets require research on new materials that incorporate elements with high EUV photon absorption cross-sections and, at the same time, are composed of small units consistent with future resolutions targets. 13,[18][19][20] Metal oxoclusters are hybrid molecular compounds 10,21 and hold great potential as resist platforms for EUV lithography applications. By choosing the right metalcomponent, they can meet the desired properties for EUV photon absorption while offering intrinsically small and homogeneous size (monodisperse) due to their molecular nature.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, molecular materials based on Zn have been investigated and have shown promising results. 19,23,24 In our approach, a denser Zn metallic oxo core is used as the inorganic building block in order to enhance the EUV absorbance of the material. The organic ligands surrounding the inorganic EUV-absorbing core are envisioned as the main factor defining the solubility properties.…”

Section: Introductionmentioning

confidence: 99%

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Stability studies on a sensitive EUV photoresist based on zinc metal oxoclusters

Thakur

Tseng

Vockenhuber

et al. 2019

J. Micro/Nanolith. MEMS MOEMS

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Background: Hybrid inorganic-organic materials have emerged as promising candidates for EUV resists. However, knowledge on their stability when deposited as thin films is essential for their performance in EUV lithography. Aim: We investigate whether the molecular structure of Zn-based metal oxoclusters is preserved upon thin film deposition and study aging processes of the thin film under different atmospheres, since these chemical changes affect the solubility properties of the material. Approach: A hybrid cluster that combines the high EUV photon absorption cross-sections of zinc and fluorine with the reactivity of methacrylate organic ligands was synthesized. The structural modifications upon thin film formation and after aging in air, nitrogen, and vacuum were studied using a combination of spectroscopic techniques. Preliminary studies on the lithographic performance of this material were performed by EUV interference lithography. Results: The Zn-based compound undergoes structural rearrangements upon thin film deposition as compared to the bulk material. The thin films degrade in air over 24 h, yet they are found to be stable for the duration and conditions of the lithography process and show high sensitivity. Conclusions: The easy dissociation of the ligands might facilitate hydrolysis and rearrangements after spincoating, which could affect the reproducibility of EUV lithography.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Stability studies on a sensitive EUV photoresist based on zinc metal oxoclusters

Thakur

Tseng

Vockenhuber

et al. 2019

J. Micro/Nanolith. MEMS MOEMS

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“…The newest, photoresists that enable sub-10 nm, hp resolution to satisfy the stringent requirements of performance and throughput imposed by the aggressive logic device-scaling are limited, even though the EUV ecosystem is ready for HVSM to the chipmakers 30 – 34 In continuation with this, a photoresist must produce patterns with a line width roughness (LWR) of <20%, 35 – 37 which necessitates a higher dose to retain chemical noise and shot noise at a tolerable level originating from the molecular nature of resists formulation and probabilistic interaction behavior of available fewer EUV photons leading to the low-energy secondary electrons (LESEs) generation in the resists dense pattern formation 38 . In unison, the dose should be low enough (≤20 mJ cm−2) 39 to enable high throughput chip manufacturing.…”

Section: Introductionmentioning

confidence: 99%

Ultrasensitive metal-organic cluster resist for patterning of single exposure high numerical aperture extreme ultraviolet lithography applications

Chauhan

Palit

Choudhary

et al. 2022

J. Micro/Nanopattern. Mats. Metro.

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Background: An incredible increase in the integration of electronic chips has pushed the semicon industries to endorse high numerical aperture (h-NA ∼ 0.5), extreme-ultraviolet (EUV) lithography (EUVL) (λ ∼ 13.5 nm) at the commercial scale. Induction of h-NA postulates EUV resists that could outperform the resolution, line pattern roughness, and sensitivity (RLS) tradeoff for chip fabricators, which is currently extremely limited. Aim:The development of EUV resist to balance RLS trade-off as well as overcome throughput limitations of h-NA EUV system to facilitate high volume semiconductor manufacturing.Approach: Here, we developed indium-methacrylic acid-based metal-organic clusters resist for h-NA, EUVL. To examine the h-NA single exposure patterning potential of the resist, prescreening by sub-10 nm next-generation lithography (NGL) tools such as electron beam lithography (EBL), and helium ion beam lithography (HIBL) were conducted as a prelude to EUV exposure.Results: Dense ∼13 nm, (l/s) patterns at ∼45 and ∼30 μC∕cm 2 were well resolved by EBL and HIBL, on the top this the line edge roughness (LER) was 2.48 AE 0.04 nm, and etch resistance ∼1.98 and ∼0.34 times lower than Si and SiO 2 ∕Si systems. Also, In-MAA MOCs resist shows ultra-sensitivity of 2.3 mJ∕cm 2 towards h-NA EUVL for patterning up to 26 nm half-pitch line patterns with LER ∼2.36 AE 0.16 nm.

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“…This motivates for the research on new materials that incorporate elements with high EUV absorption cross-sections but are composed of small units in agreement with the targeted future resolutions. 7,[9][10][11][12] Metal oxoclusters are hybrid molecular compounds that are ideal platforms for this purpose. By choosing the right metalcomponent, they can meet the desired properties for EUV photon absorption and they are intrinsically small and have a homogeneous size (monodispersity).…”

Section: Introductionmentioning

confidence: 99%

“…Recently, molecular materials based on Zn have been investigated and have shown promising results. 11,14,15 In our approach, a denser Zn metallic oxo core is used as the building block in order to enhance the EUV absorbance of the material. The organic ligands surrounding a condensed EUV absorbing core are envisioned as the main factor for the solubility properties and play a major role in the reactivity of the material, which determines in turn the solubility switch upon exposure.…”

Section: Introductionmentioning

confidence: 99%

Zinc-based metal oxoclusters: towards enhanced EUV absorptivity

Thakur

Vockenhuber

Ekinci

et al. 2019

Extreme Ultraviolet (EUV) Lithography X

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The cost-effectiveness and future progress of EUV (13.5 nm) lithography will largely depend on the resist technology development. Hybrid inorganic-organic photoresists have emerged as promising materials of EUV and have gained increasing attention in recent years. A crucial aspect for hybrid materials is their stability and the preservation of their molecular integrity when deposited as thin films. In this work, we study novel zinc (Zn) oxoclusters as molecular hybrid photoresists. Our aim is to combine the reactivity of methacrylate organic ligands with an inorganic cluster with high EUV photon absorption cross-section arising from this metal. To gain understanding on the shelf life of this material, changes in their structure under different conditions were monitored employing a combination of different spectroscopic techniques. The sensitivity of these oxoclusters under EUV light was investigated and their patterning performance is evaluated using EUV interference lithography. Our results indicate that these novel Zn-based oxoclusters are promising candidates for EUV lithography owing to their high dose sensitivity. Nevertheless, the labile nature of the methacrylate ligands has an important impact in the development process which seems to hamper their reproducibility. This work contributes to the understanding of the pitfalls and advantages of hybrid molecular resists.

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EUV metal oxide hybrid photoresists: ultra-small structures for high-resolution patterning

Cited by 3 publications

References 6 publications

Stability studies on a sensitive EUV photoresist based on zinc metal oxoclusters

Stability studies on a sensitive EUV photoresist based on zinc metal oxoclusters

Ultrasensitive metal-organic cluster resist for patterning of single exposure high numerical aperture extreme ultraviolet lithography applications

Zinc-based metal oxoclusters: towards enhanced EUV absorptivity

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