Showing papers by "Deirdre L. Olynick published in 2012"

High Aspect Ratio Sub‐15 nm Silicon Trenches From Block Copolymer Templates

Abstract: High-aspect-ratio sub-15-nm silicon trenches are fabricated directly from plasma etching of a block copolymer mask. A novel method that combines a block copolymer reconstruction process and reactive ion etching is used to make the polymer mask. Silicon trenches are characterized by various methods and used as a master for subsequent imprinting of different materials. Silicon nanoholes are generated from a block copolymer with cylindrical microdomains oriented normal to the surface.

Single digit nanofabrication by step-and-repeat nanoimprint lithography.

Abstract: A novel strategy for fabricating nanoimprint templates with sub-10 nm patterns is demonstrated by combining electron beam lithography and atomic layer deposition. Nanostructures are replicated by step-and-repeat nanoimprint lithography and successfully transferred into functional material with high fidelity. The process extends the capacity of step-and-repeat nanoimprint lithography as a single digit nanofabrication method. Using the ALD process for feature shrinkage, we identify a size dependent deposition rate.

Plasmon resonance tuning in metallic nanocavities

Abstract: Nanocavities fabricated in a metallic surface have important and technologically useful properties of complete light absorption and strong field enhancement. Here, we demonstrate how a nanometerthick alumina deposition inside such a cavity can be used to gain an exquisite control over the resonance wavelength. This process allows achieving a precise control over the spectral response and is completely reversible allowing many tuning attempts to be made on a single structure until the optimum performance is achieved.

Sub-20 nm laser ablation for lithographic dry development

Abstract: Pattern collapse of small or high aspect ratio lines during traditional wet development is a major challenge for miniaturization in nanolithography. Here we report on a new dry process which combines high resolution resist exposure with selective laser ablation to achieve high resolution with high aspect ratios. Using a low power 532 nm laser, we dry develop a normally negative tone methyl acetoxy calix(6)arene in positive tone to reveal sub-20 nm half-pitch features in a ∼100 nm film at aspect ratios unattainable with conventional development with ablation time of 1–2 s per laser pixel (∼600 nm diameter spot). We also demonstrate superior negative tone wet development by combining electron beam exposure with subsequent laser exposure at a non-ablative threshold that requires far less electron beam exposure doses than traditional wet development.

Signal propagation in dipole coupled nanomagnets for logic applications

Abstract: As conventional Silicon-based transistors reach their scaling limits, novel devices for performing computations have emerged as alternatives to continue the improvements in information technology that have benefited society over the past 40 years. One candidate that has shown great promise recently is a device that performs logical computations using dipole coupled nanomagnets. In this paper, we discuss recent advances that have led to a greater understanding of signal propagation in nanomagnet arrays. In particular, we highlight recent experimental work towards the imaging of a propagating magnetic cascade.

Selective laser ablation of radiation exposed methyl acetoxy calix(6)arene

Abstract: The chemical mechanism of recently discovered high resolution laser dry development of methyl acetoxy calix(6)arene is probed. This process is an alternative to wet development and allows high aspect ratio patterns to be formed in resist without pattern collapse. Using infrared, Raman, and fluorescence spectroscopies, the authors have observed a reduction of the acetoxy groups, formation of hydroxyls and extended conjugation of the system due to the cross-linking under e-beam exposed film. These changes increase the laser absorption of the resist creating species that ablates under ambient conditions. Based on these studies, the authors surmise that chemical species formed during the e-beam exposure accelerate the ablation thus setting the basis for the selective ablation.