Scott Lewis

California Institute of Technology | CIT · Department of Applied Physics & Materials Science

Metal-organic materials such as [NH2(CH2-CH=CH2)2][Cr7NiF8(Pivalate)16] can act as negative tone resists for electron beam lithography (EBL) with high-resolution patterning of sub-40 nanometer pitch while exhibiting ultrahigh dry etch selectivities >100:1 and giving line dose exposures >11,000 pC/cm. It is clear that the resist sensitivity is too l...

A new class of electron bean negative tone resist materials has been developed based on heterometallic rings. The initial resist performance demonstrates a resolution of 15 nm half‐pitch but at the expense of a low sensitivity. To improve sensitivity a 3D Monte Carlo simulation is used that utilizes a secondary and Auger electron generation model....

An approach is presented for nanoscale patterning of zinc oxide (ZnO) using electron beam (e-beam) lithography for future nanoelectronic devices and for hard lithographic masks. Zinc acetate (Zn₄O(CH₃COO)₆) films were exposed using a scanning electron microscope (SEM), causing decomposition of Zn₄O(CH₃COO)₆ into ZnO. The exposure of Zn₄O(CH₃COO)₆ u...

Field emission devices are promising candidates to replace silicon FinFETs as next-generation nanoelectronic components. For these devices to be adopted, nanoscale field emitters with nanoscale gaps between them need to be fabricated, requiring the transfer of e.g. sub-10 nm patterns with sub-20 nm pitch into substrates like silicon and tungsten. N...

Coherent diffraction imaging (CDI) or lensless X-ray microscopy has become of great interest for high spatial resolution imaging of, e.g., nanostructures and biological specimens. There is no optics required in between an object and a detector, because the object can be fully recovered from its far-field diffraction pattern with an iterative phase...

A new class of resist materials has been developed that is based on a family of heterometallic rings. The work is founded on a Monte Carlo simulation that utilizes a secondary and Auger electron generation model to design resist materials for high resolution electron beam lithography. The resist reduces the scattering of incident electrons to obtai...

A new resist material for electron beam lithography has been created that is based on a supramolecular assembly. Initial studies revealed that with this supramolecular approach, high-resolution structures can be written that show unprecedented selectivity when exposed to etching conditions involving plasmas.

A new resist material for electron beam lithography has been created that is based on a supramolecular assembly. Initial studies revealed that with this supramolecular approach, high-resolution structures can be written that show unprecedented selectivity when exposed to etching conditions involving plasmas.

In this chapter, the focus was on investigating a suitable technology to fabricate the next generation optical photomasks with a one-step process. This was achieved by a fabricating a novel nanocomposite electron beam resist that incorporated azo dyes into polymethylmethacrylate (PMMA). The azo dyes were introduced to attenuate the ultraviolet radi...

Electron beam lithography is a well-established tool suitable for the modification of substrate surface chemistry. It therefore follows that the deposition and self-assembly of nanoparticles on a surface can be directed using this method. This work explores the effect of electron dose on the electron beam lithographic patterning of self-assembled m...

A novel photolithographic technique using a periodic hexagonal close packed silver nanoparticle 2D array photo mask has been demonstrated to transfer a nano-pattern into a photoresist using I line proximity photolithography. A 30 nm hexagonal close packed silver nanoparticle 2D array pattern with a 50 nm period has been successfully transferred int...

Poly(methylmethacrylate) (PMMA) based nanocomposite electron beam resists have been demonstrated by spin coating techniques. When TiO2 and Al2O3 nanoparticles were directly dispersed into the PMMA polymer matrix, the resulting nanocomposites produced poor quality films with surface roughnesses of 322 and 402 nm respectively. To improve the surface...

An electron beam resist called SML-2000 has been investigated. It has produced nano-structures with a high aspect ratio of 10:1 using an acceleration voltage of 25KV. This is significant, as comparing this result with PMMA, it was found from the Monte Carlo simulations that PMMA had inherent problems of generating secondary electrons which contribu...

C(l)OVER is a multi-frequency experiment optimised to measure the Cosmic Microwave Background (CMB) polarization, in particular the B-mode component. C(l)OVER comprises two instruments observing respectively at 97 GHz and 150/225 GHz. The focal plane of both instruments consists of an array of corrugated feed-horns coupled to TES detectors cooled a...

A novel photolithographic technique using a periodic hexagonal close packed silver nanoparticle 2D array photo mask has been demonstrated to transfer a nano-pattern into a photoresist using G–I line proximity photolithography. This method can be made to precisely control the spacing between nanoparticles by using temperature. The high-density nanop...

We describe the objectives, design and predicted performance of Clover, a fully-funded, UK-led experiment to measure the B-mode polarisation of the Cosmic Microwave Background (CMB). Three individual telescopes will operate at 97, 150 and 225 GHz, each populated by up to 256 horns. The detectors, TES bolometers, are limited by unavoidable photon no...

The transfer of a three dimensional grey–scale pattern from a polymer composite to a photoresist has been demonstrated. The grey scale structure was fabricated using variable dose electron beam lithography. The optical transparency of the electron beam resist was reduced by the addition of Al 2 O 3 and TiO 2 nanoparticles. The reduction in optical...