A5066365150- Advancements in Photolithography Techniques
- Electron and X-Ray Spectroscopy Techniques
- Semiconductor materials and devices
- X-ray Spectroscopy and Fluorescence Analysis
- Quantum, superfluid, helium dynamics
- Atomic and Subatomic Physics Research
- High-pressure geophysics and materials
- Corrosion Behavior and Inhibition
- Organometallic Compounds Synthesis and Characterization
- Integrated Circuits and Semiconductor Failure Analysis
- Cultural Heritage Materials Analysis
- Cold Atom Physics and Bose-Einstein Condensates
Lawrence Berkeley National Laboratory
2014-2022
University of California, Berkeley
2019-2022
Chinese University of Hong Kong
2014
Helium nanodroplets are considered ideal model systems to explore quantum hydrodynamics in self-contained, isolated superfluids. However, exploring the dynamic properties of individual droplets is experimentally challenging. In this work, we used single-shot femtosecond x-ray coherent diffractive imaging investigate rotation single, superfluid helium-4 containing ~10(8) 10(11) atoms. The formation vortex lattices inside confirmed by observing characteristic Bragg patterns from xenon clusters...
Extreme ultraviolet (EUV)-induced radiation exposure chemistry in organotin-oxo systems, represented by the archetypal [(R-Sn)12O14(OH)6](A)2 cage, has been investigated with density functional theory. Upholding existing experimental evidence of Sn-C cleavage-dominant chemistry, computations have revealed that either electron attachment or ionization can single-handedly trigger tin-carbon bond cleavage, partially explaining current EUV sensitivity advantage metal oxide systems. We tin atoms...
Slow electrons (with energy below 10 eV) play an important role in nature and technology. For instance, they are believed to initiate solubility change extreme ultraviolet resists. Depending on their mobility, such secondary can lead image blur degradation of patterning resolution. Hence, it is characterize the transport slow by measuring parameters as effective attenuation length (EAL). We present a technique that allows for prompt characterization EAL polymer films. In this experiment,...
Advancements in x-ray free-electron lasers on producing ultrashort, ultrabright, and coherent pulses enable single-shot imaging of fragile nanostructures, such as superfluid helium droplets. This technique gives unique access to the sizes shapes individual In past, droplet characteristics have only been indirectly inferred by ensemble averaging techniques. Here, we report size distributions both pure doped droplets collected from produced free-jet expansion through a 5 μm diameter nozzle at...
In extreme ultraviolet (EUV) lithography, chemistry is driven by secondary electrons. A deeper understanding of these processes needed. However, electron-driven are inherently difficult to experimentally characterize for EUV materials, impeding targeted material engineering. computational framework needed provide information rational engineering and identification at a molecular level. We demonstrate that density functional theory calculations can fulfill this purpose. first primary electron...
In this preliminary computational chemistry study, we report excitation selectivity in a model tin-oxo molecular resist. Upon impact ionization, organic side chains connected to 6-coordinated tin atoms (located near the charge balancing ligands) are preferentially destabilized. electron addition, conversely, 5-coordinated on central belt) Inferring from binding energies, ionization induced processes likely have smaller spatial extent than attachment process.
In Extreme Ultraviolet (EUV) lithography, chemistry is driven by secondary electrons. A deeper understanding of these processes vital to targeted engineering materials. As electron interactions are non-discriminative, studying directly in condensed phase with experiments extremely challenging. Proxy such as gas and solution only viable a limited subset materials, limiting their use for large scale material screening. First principles quantum calculations have been adopted various industries...
In EUV lithography, radiation chemistry is largely different from DUV. Engineers have explored self-assembled monolayers (SAM) in the context of lithography and some their properties could be utilized EUV. We study SAMs interaction with substrates using quantum chemistry. Interface between resists underlayers playing an increasingly important role it conceivable that resist molecules near interface are susceptible to activation by electrons originated substrate. For monolayer nature...
EUV photon absorption by a resist film leads to emission of photoelectron and several low kinetic energy secondary electrons. The "universal curve", used in X-ray spectroscopy, suggests that the electrons may travel tens hundreds nanometers solids until they inelastically scatter. fact long distances before initiate chemical reactions ultimately result blur aerial image, reducing contrast subsequently resolution resist. In this work, we will present an experimental approach determine...
Metal-organic systems have shown great promise as EUV resists. They demonstrated good sensitivity and etch resistance while maintaining high resolution low line edge roughness, making them a potential pathway to modify the tradeoff between resolution, common organic chemically amplified In particular, tin-based attracted significant interest two known families of fab-ready metal resist are based on organotin compounds. Part this derives from absorption cross-section tin, but an equally...