/pdf/micro-total-analysis-systems-1-introduction-theory-and-27f7corp18.pdf

Micro Total Analysis Systems. 1. Introduction, Theory, and Technology

Nanoimprint lithography (NIL) is a nonconventional lithographic technique for high-throughput patterning of polymer nanostructures at great precision and at low costs. Unlike traditional lithographic approaches, which achieve pattern definition through the use of photons or electrons to modify the chemical and physical properties of the resist, NIL relies on direct mechanical deformation of the resist material and can therefore achieve resolutions beyond the limitations set by light diffraction or beam scattering that are encountered in conventional techniques. This Review covers the basic principles of nanoimprinting, with an emphasis on the requirements on materials for the imprinting mold, surface properties, and resist materials for successful and reliable nanostructure replication.

/pdf/nanoimprint-lithography-methods-and-material-requirements-csc83swyi1.pdf

Nanoimprint Lithography: Methods and Material Requirements**

Models and computational methods for dynamic friction phenomena

: This work addresses the general problems of formulating continuum models of a large class of dynamic frictional phenomena and of developing computation methods for analyzing these phenomena. Of particular interest are theories which can adequately predict stick slip motion, frictional damping in structural dynamics, and sliding resistance. This work id divided into three principal parts. In Part I, a large body of experimental and theoretical literature on friction is critically reviewed and interpreted as a basis for models of dynamic friction phenomena. In part II, continuum models of interfaces are developed which simulate key interface properties identified in Part I. Variational principles for a class of dynamic friction problems are also established. In Part III, finite element models and numerical algorithms for analyzing dynamic friction are presented. Also, a dynamic stability analysis is presented in which it is established that stick slip motion can be associated with dynamic instability of the governing nonlinear system for certain ranges of slip velocity and coefficient of friction. Numerical results suggest that the new models derived here can satisfactorily depict a large and important class of dynamic friction effects. Keywords: Friction damping; Sliding friction models; Finite element methods; and Structural dynamic.

Models and Computational Methods for Dynamic Friction Phenomena. 1. Physical Aspects of Dynamic Friction. 2. Continuum Models and Variational Principles for Dynamic Friction. 3. Finite Element Models and Numerical Analysis

Nanoimprint is an emerging lithographic technology that promises high-throughput patterning of nanostructures. Based on the mechanical embossing principle, nanoimprint technique can achieve pattern resolutions beyond the limitations set by the light diffractions or beam scatterings in other conventional techniques. This article reviews the basic principles of nanoimprint technology and some of the recent progress in this field. It also explores a few alternative approaches that are related to nanoimprint as well as additive approaches for patterning polymer structures. Nanoimprint technology can not only create resist patterns as in lithography but can also imprint functional device structures in polymers. This property is exploited in several non-traditional microelectronic applications in the areas of photonics and biotechnology.

https://deepblue.lib.umich.edu/bitstream/handle/2027.42/48920/d4_11_r01.pdf?sequence=2

Recent progress in nanoimprint technology and its applications

Room-temperature nanoimprint lithography (RT-NIL) technology has been developed to overcome critical dimensions and pattern placement errors caused by thermal expansion in the conventional nanoimprint lithography (NIL) process. We propose RT-NIL using hydrogen silsequioxane (HSQ) instead of the poly(methylmethacrylate) used in conventional NIL. We demonstrate HSQ-replicated patterns with a 90 nm diameter hole and 50 nm linewidth for room-temperature replications. Furthermore, we have developed new nanotransfer printing technology utilizing the adhesion characteristics of HSQ. We also demonstrate the transfer of photoresist and Au patterns from a mold to a substrate.

Room-temperature nanoimprint and nanotransfer printing using hydrogen silsequioxane

A compact nanoimprint lithography (NIL) system using the driving power of a stepping motor has been developed. Compared to a conventional NIL system with a hydraulic press, there are some additional features of the NIL system such as compactness and low cost. We propose the use of spin on glass (SOG) instead of PMMA to avoid thermal expansion and demonstrate SOG patterns with 200 nm linewidths at room temperature replications using the NIL system. The SOG patterns were transferred to gold metal using liftoff and to a silicon substrate by reactive ion etching.

Room temperature replication in spin on glass by nanoimprint technology

An investigation was conducted to determine the friction and wear characteristics of hot-pressed silicon nitride. Sliding produced wear debris and a damaged surface. The physical and crystallographic morphology of surfaces was compared with that of diamond ground surfaces. Wear tests were done with pin-on-disk apparatus at a load of 10N with various sliding speeds to 780 mm/s, and in four different environments which included in dry nitrogen, in air at humidities of 50 percent RH and 90 percent RH, and in distilled water. The results of the wear experiments indicated that residual α-silicon nitride was transformed into β-silicon nitride. Adsorbed water appeared to enhance plastic flow of the surface and reduced both the wear rate and friction. A second investigation was conducted to correlate the coefficient of friction with the fracture toughness of silicon nitride, silicon carbide, aluminum oxide and zirconium oxide. The friction experiments were done in reciprocating sliding, using spherical diamonds. Two tip radii, 0.005 mm and 0.1 mm were used over a range of load of 0.1 to 3N and a speed of 0.17 mm/s. The coefficient of friction was found to be inversely correlated with fracture toughness of all four ceramics in several conditions. Frictional anisotropy was also observed in the hot-pressed silicon nitride.

Friction and Wear of Hot Pressed Silicon Nitride and Other Ceramics

Room-temperature nanoimprint lithography (RT-NIL) technology has been developed to overcome critical dimensions and pattern placement error due to thermal expansion in the conventional nanoimprint lithography (NIL) process. We propose RT-NIL using hydrogen silsequioxane (HSQ) instead of PMMA used in conventional NIL, and demonstrate HSQ replicated patterns with 90 nm hole diameter and 50 nm linewidth realized by room-temperature replications. We performed step-and-repeat replications using HSQ on a 1.5 in. wafer and evaluated the uniformity of the imprinted HSQ patterns.

https://iopscience.iop.org/article/10.1143/JJAP.41.4198/pdf

Hiroyuki Ishigaki

Papers

Room-temperature nanoimprint and nanotransfer printing using hydrogen silsequioxane

Room temperature replication in spin on glass by nanoimprint technology

Friction and Wear of Hot Pressed Silicon Nitride and Other Ceramics

Room Temperature Nanoimprint Technology Using Hydrogen Silsequioxane (HSQ)

Effect of adsorbed water on friction of hot-pressed silicon nitride and silicon carbide at slow speed sliding