Advanced development techniques for metal-based EUV resists

Hotalen, Jodi; Murphy, Michael; Earley, William; Vockenhuber, Michaela; Ekinci, Yasin; Freedman, Daniel A.; Brainard, Robert L.

doi:10.1117/12.2258126

Cited by 10 publications

(6 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The proposed photoproduct has been synthesized in literature 22 . These three compounds are typically negative tone when developed with simple organic solvents, though recent work has demonstrated that positive tone behavior can be achieved through specialized development 23 . Two trends seem to correlate with the increase in sensitivity, the increase in EUV absorption in the order of Cr < Fe < Co (Sec.…”

Section: Cr2+mentioning

confidence: 99%

Reactivity of metal-oxalate EUV resists as a function of the central metal

et al. 2017

Self Cite

View full text Add to dashboard Cite

Extreme Ultraviolet light (EUV, ~13.5 nm) is the likely subsequent technology for high volume manufacturing for the microelectronics industry. Traditional EUV photoresists have been composed of organic compounds which are moderately transparent to EUV. Resist stochastics and sensitivity can be improved by increasing the number of photons absorbed. Molecular organometallic resists are a type of metal containing resist aimed at improving EUV absorption. This work focuses on studying the role of the metal center (Metal = Co, Fe, Cr) in an oxalate complex by comparing the number of absorbed photons and the photoelectron reactivity in each compound.In the study presented here, the EUV absorption coefficients are determined experimentally by measuring the transmission through a resist coated on a silicon nitride membrane using an Energetiq EQ-10M xenon plasma EUV source. Additionally, the photochemistry is evaluated by monitoring outgassing reaction products. This particular resist platform eliminates oxalate ligands when exposed to electrons or EUV photons resulting in a solubility difference between the exposed and unexposed regions. In the process, carbon dioxide is produced and is monitored using mass spectrometry, where quantitative values are obtained using a calibration technique.For the metal oxalate complexes studied, the absorption of EUV changed minimally due to the low concentrations of metal atoms. However, EUV and electron reactivity greatly changed between the three compounds likely due to the reducibility of the metal center. A correlation is shown between Esize and the reducibility of each photoresist.

show abstract

Section: Cr2+mentioning

confidence: 99%

Reactivity of metal-oxalate EUV resists as a function of the central metal

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…Metal oxide resists (MORs) were the most interesting ones among them as the metals have high EUV absorption . Several resist platforms with high EUV absorption cross section, containing metals such as Sn, Hf, Zr, and Sb, have also been reported. − Apart from high absorption, the ligands around the metal core in MOR offer numerous reaction sites which can increase sensitivity by the efficient use of secondary electrons. They showed resolution down to 10 nm using a 0.5 numerical aperture (NA) Berkeley microfield exposure tool (BMAT) and interference lithography. , However, due to the presence of moisture in ambient, the critical dimensions (CD) printed with MOR vary from wafer to wafer .…”

Section: Introductionmentioning

confidence: 99%

Extreme Ultraviolet Lithographic Performance and Reaction Mechanism of Polymeric Resist─Utilizing Radical- and Acid-Amplified Cross-Linking

Naqvi,

Enomoto,

Machida

et al. 2024

Chem. Mater.

View full text Add to dashboard Cite

Extreme ultraviolet (EUV) lithography is a promising technology for making chips beyond 7 nm technology node; however, it comes with its own challenges. One of them is the need to find a suitable EUV resist. Photoresist performance is gauged by the resolution, LER, and sensitivity trade-off. However, the primary challenge for the photoresist in EUV lithography is the major shift in reaction chemistry relative to that in deep ultraviolet (DUV) lithography. The interaction of the EUV photon (92 eV) with the widely used conventional chemically amplified resist (CAR) is different than that of the DUV photon (5−6 eV). The DUV photon excites only the valence electrons of the photo-acid generator in CAR, which results into acid generation. However, a high-energy EUV photon can ionize the CAR polymer matrix. This leads to the generation of a cascade of secondary electrons. Thus, in addition to acid generation, other chemical reactions like bond scission and cross-linking occur by the interactions between resist and secondary electrons. Apart from chemically amplified reactions, CARs are not very efficient at utilizing the additional pathways offered by secondary electrons. Moreover, stochastics, arising from photon and chemical shot noise, are an additional challenge for an EUV resist. Therefore, there is a need for an alternative photoresist to CAR. Herein, we report a single polymer chain negative tone photoresist. The resist has an acid generator, an organotin moiety, and an acid reactive unit attached to a polymer chain. The resist is designed to use EUV-generated secondary electrons to generate acid and polymer-bound radicals. The polymer-bound radicals and acid amplification reaction can induce cross-linking among polymer chains to create a negative tone solubility switch. In this study, the EUV printability study and reaction mechanism of the resist are elucidated. Electron transfer reactions for radical generation were studied with the help of nanosecond pulse radiolysis and γ-radiolysis. Liquid chromatography and mass spectrometry were used to identify possible acid-amplified reactions.

show abstract

“…Metal oxide photoresists are potential candidates for the next generation; however, the conventional developer is not applicable to the development process for metal oxide photoresists. 8,9) On the other hand, TMAH is highly toxic to organisms. In previous research studies, aqueous solutions of other tetraalkylammonium hydroxides (TAAHs), such as tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TProAH), and tetrabutylammonium hydroxide (TBAH), were applied to the development of CARs to study the dissolution dynamics.…”

Section: Introductionmentioning

confidence: 99%

Dissolution dynamics of poly(4-hydroxystyrene) partially protected with t-butoxycarbonyl group in alkyltrimethylammonium hydroxide aqueous developers

Wang,

Kozawa

2024

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

Novel developers with low biotoxicity have attracted considerable attention with respect to ensuring environmental sustainability. In this study, the dissolution dynamics of poly(4-hydroxylstyrene) (PHS) partially protected with a t-butoxycarbonyl (t-Boc) group in alkyltrimethylammonium hydroxide and tetraethylammonium hydroxide aqueous solutions (0.26 N) were investigated by the quartz crystal microbalance method. One of the methyl groups of tetramethylammonium hydroxide (TMAH) was substituted by ethyl, propyl, and butyl groups. Depending on the developer used, the dissolution dynamics of PHS and t-Boc-protected PHS (t-Boc PHS) films showed different tendencies. The dissolution rate of PHS was higher in the TMAH developer than in the butyltrimethylammonium hydroxide (B-TMAH) developer, whereas that of the t-Boc PHS (30 mol%-protected) film was higher in the B-TMAH developer than in the TMAH developer. The elongation of one of the alkyl chains is beneficial for the penetration of the developer and the separation of nonpolar molecular interactions among t-Boc PHS molecules.

show abstract

Advanced development techniques for metal-based EUV resists

Cited by 10 publications

References 14 publications

Reactivity of metal-oxalate EUV resists as a function of the central metal

Reactivity of metal-oxalate EUV resists as a function of the central metal

Extreme Ultraviolet Lithographic Performance and Reaction Mechanism of Polymeric Resist─Utilizing Radical- and Acid-Amplified Cross-Linking

Dissolution dynamics of poly(4-hydroxystyrene) partially protected with t-butoxycarbonyl group in alkyltrimethylammonium hydroxide aqueous developers

Contact Info

Product

Resources

About