We describe how focused ion beam (FIB) direct write technology may be combined with microcontact printing (μCP) and other pattern transfer techniques to enable nanoscale fabrication of complex patterns over both curved and planar surfaces. Nanoscale printheads are fabricated by direct sputtering or deposition (Pt or SiO2) in the FIB. These printheads are capable of transferring 100 nm features over fields of view up to 1 mm2, onto planar and curved surfaces. We are also investigating the concept of “programmable” printheads by fabrication of individually addressable printhead arrays, coupled with selective desorption of a relevant transfer medium (e.g. hexadecanethiol self-assembled monolayers) by heating or by application of an electric field

Direct writing by locally induced chemical vapor deposition has been applied to direct-write tailor-made microstructures of siliconoxide for modification and repair of microelectronic circuits. Focused ion beam (FIB) tools are used for locally confined deposition of dielectric material in the deep sub-µm range. State-of-the-art procedures typically provide insufficient dielectrics with high leakage currents and low breakdown voltage. The detailed investigation of the deposition mechanisms in this study proposes an approach to significantly improve dielectric material properties. Siloxane and oxygen as volatile precursors introduced in a vacuum chamber are used to deposit siliconoxide at ambient temperatures on various substrates such as Si, GaAs, or metals. The deposition process was initiated by a focused Ga+-beam. As elementary electronic test vehicles for a systematic electrical investigation ion beam induced depositions in of capacitor architectures are applied. The chemical composition of the layers is investigated by secondary ion mass spectroscopy (SIMS) and reveals effects of atomic mixing at the interfaces. The variation of process parameters such as ion energy and ion dose, scan time and delay time lead to a better understanding of the mechanisms. The composition of the precursor gas mixture is of significant influence on insulating properties. The results demonstrate that optimized FIB-induced deposition of dielectrics offers a new window for in-situ post-processing of integrated circuits

Electron beam induced deposition with two noble metal precursors (Rhodium and Gold) having the same halogeno and trifluorophosphine ligands is presented. The deposit geometry of lines and freestanding bridges is discussed with respect to electron energy, beam shape, and backscattered electron distribution. Electron beam heating effects are estimated to be negligible in our deposition conditions. Using PF3AuCl, lines of percolating gold grains were deposited with electrical resistivities as low as 22μωcm at room temperature (Au: 2.2μωcm). Auger electron analysis shows about 60at% Rh in deposits obtained with [RhCI(PF3)2]2, however the resistivity of 1ωcm is high compared to 4.5μωcm of pure Rh.

Thermal Spray is a directed spray process, in which material, generally in molten form, is accelerated to high velocities, impinging upon a substrate, where a dense and strongly adhered deposit is rapidly built. In the case of ceramic deposits, it is necessary to bring the particles to well above the melting point, which is achieved by either a combustion flame or a thermal plasma arc. The deposit microstructure and, thus, properties, aside from being dependent on the spray material, rely on the processing parameters, which are numerous and complex. In recent years, through concerted, integrated efforts of the Center for Thermal Spray Research at the State University of New York at Stony Brook and others, significant fundamental understanding of the process has been achieved, allowing for an enhanced control of the process.

Polycrystalline silicon deposits were formed on a monocrystalline silicon substrate by thermal spraying. The resulting structure exhibits a device characteristic. Pressure-induced transformations of silicon, namely, Si-III (BC-8) and Si-IX are identified by X-ray diffraction in a Si-I matrix on deposits formed by vacuum plasma spray. The presence of the Si-III and Si-IX indicates that the pressure-quenched silicon deposit is highly conductive, as determined by four-point van der Pauw resistivity measurement. Hall mobility measurements, combined with photoconductivity results, indicate that the highly conductive silicon deposit displays the same range of mobility as a polycrystalline deposit containing only Si-I. The silicon deposit, with or without metastable phases, displays the same photoconductivity properties. The silicon deposit on a monocrystalline silicon substrate exhibits rectifying I–Vcharacteristics, possibly caused by band bending of trapping states associated with impurities segregating at the polycrystalline deposit/monocrystalline substrate interface

The current fabrication methods used to produce many antennas are limited by variances in the precision and skill levels of individual laborers. These variances slow production and often create inconsistent results. As radio-frequency transmitter and receiver design moves towards higher operating frequencies, the physical dimensions of the supporting antennas decrease. Smaller sizes add new complexities to the fabrication of these antennas. Several designs that may be considered high-performance antennas are difficult to reproduce; many times, they cannot be fabricated at all due to the sophisticated patterning and precision necessary for successful function. Direct-write technologies provide the tools necessary to fabricate unique patterns in two and three dimensions. A demonstration of a directly written antenna, constructed from a silver-based thick-film paste pen-deposited onto cylindrical alumina substrates, is presented for review

The synthesis of two new tert-butyl carbonic anhydride monomers, 4-vinylbenzoic and methacrylic tert-butyl carbonic anhydride was achieved successfully. Radical polymerization at 45°C yielded tert-butyl pyrocarbonate protected materials. Thermographic analysis showed that both polymers decompose cleanly at 135°C. The lithographic performance of both materials was evaluated in presence of 2,4,6-tris-(trichloromethyl)-s-triazine as photoacid generating species. It was demonstrated that the large polarity change resulted in a chemically amplified positive photoresist system

A large-scale plasma source immersion ion implantation (PSII) system with planar coil RFI plasma source has been used to study an inkless, deposition-free, mask-based surface conversion patterning as an alternative to direct writing techniques on large-area substrates by implantation. The apparatus has a 0.61 m ID and 0.51 m tall chamber, with a base pressure in the 10−8 Torr range, making it one of the largest PSII presently available. The system uses a 0.43 m ID planar rf antenna to produce dense plasma capable of large-area, uniform materials treatment. Metallic and semiconductor samples have been implanted through masks to produce small geometric patterns of interest for device manufacturing. Si gratings were also implanted to study application to smaller features. Samples are characterized by AES, TEM and variable-angle spectroscopic ellipsometry. Composition depth profiles obtained by AES and VASE are compared. Measured lateral and depth profiles are compared to the mask features to assess lateral diffusion, pattern transfer fidelity, and wall-effects. The paper also presents the results of MAGIC calculations of the flux and angle of ion trajectories through the boundary layer predicting the magnitude of flux as a function of 3-D location on objects in the expanding sheath

In this work we investigate the lateral dye distribution resulting from the dye doping of a thin polymer film by ink-jet printing (UIP) for the integration of color organic light emitting diodes (OLED's). The dye is found to segregate into distinct outer rings following rapid droplet evaporation, while slower evaporation rates are found to significantly reduce (or eliminate) this effect. The dye segregation phenomena are found to depend critically on the mechanisms of droplet evaporation. Good dye uniformity was obtained using a low vapor pressure solvent, and integrated, 250 micron red, green, and blue polymer organic light emitting diodes (OLED's) were fabricated with this technique. These devices had good color uniformity over most of the device area and similar electrical properties to comparable spin-coated devices without IJP

One-micrometer wide copper lines are patterned by direct imprinting and thermolysis. First, a layer of plastic copper hexanoate is spun on a substrate and patterned by direct imprint. Then the copper hexanoate line pattern is converted to copper metal lines by thermal and hydrogen anneals. The converted copper film resistivity is ∼8 μωcm. The direct imprinting of a fine metal pattern points the way to the direct patterning of device materials at high resolution

The liquid embossing process, devices made by this process, and their characteristics are presented. Structures fabricated and discussed here include: conductive lines with cross line resistance greater than 100 Gω and resistivities 4 times that of the bulk material, multilayer structures with etched sacrificial materials, vias that conduct through an embossed insulating layer, photodetectors made with nanocrystal solutions of CdSe, and all printed inorganic field effect transistors

The ability to engineer ordered arrays of objects on multiple length scales has potential for applications such as microelectronics, sensors, wave guides, and photonic lattices with tunable band gaps. Since the invention of surfactant templated mesoporous sieves in 1992, great progress has been made in controlling different mesophases in the form of powders, particles, fibers, and films. To date, although there have been several reports of patterned mesostructures, materials prepared have been limited to metal oxides with no specific functionality. For many of the envisioned applications of hierarchical materials in micro-systems, sensors, waveguides, photonics, and electronics, it is necessary to define both form and function on several length scales. In addition, the patterning strategies utilized so far require hours or even days for completion. Such slowprocesses are inherently difficult to implement in commercial environments. We present a series of new methods of producing patterns within seconds. Combining sol-gel chemistry, Evaporation-Induced Self-Assembly (EISA), and rapid prototyping techniques like pen lithography, ink-jet printing, and dip-coating on micro-contact printed substrates, we form hierarchically organized silica structures that exhibit order and function on multiple scales: on the molecular scale, functional organic moieties are positioned on pore surfaces, on the mesoscale, mono-sized pores are organized into 1-, 2-, or 3-dimensional networks, providing size-selective accessibility from the gas or liquid phase, and on the macroscale, 2-dimensional arrays and fluidic or photonic systems may be defined. These rapid patterning techniques establish for the first time a link between computer-aided design and rapid processing of self-assembled nanostructures

A numerical tool is developed to simulate the optical and thermal interactions of selected lasers with precursors and substrates in support of the emerging technology for the direct write of Mesoscopic Integrated Conformal Electronics (MICE). The code couples the Discrete Ordinate Method (DOM) radiation model with the multi-physics computation fluid dynamics code CFD-ACE to predict the conductive and radiative heat transport in the process

This paper provides a brief overview of the numerical model. Selected simulations are presented including comparison with empirical data. The capabilities, limitations, and potential applications of the model with respect to MICE are discussed. Future model enhancements are proposed

As the trend towards device miniaturisation continues, surface effects and the thermal stability of metal deposits becomes increasingly important. We present here a study of the morphology and composition of platinum films, produced by the UV-induced decomposition of organometallic materials, under various annealing conditions. The surface composition of the metal deposits was studied by X-ray photoelectron spectroscopy, both as-deposited and following thermal treatment. In addition, the morphology of the surface was studied by atomic force microscopy which enabled the investigation of film restructuring. These studies were performed over a range of temperatures up to 1000°C in air and up to 600°C in reducing environments. Complementary information regarding the film morphology has been obtained from transmission electron microscopy. The data has been used to provide an insight into the effects of elevated temperatures on metal films deposited by a direct write method

A computational model for simulating laser-guided particle deposition process is described. This model solves for the transport of gas and particle phases in a fully coupled manner. The optical forces on the particles are evaluated from Mie theory based on local laser intensity. Simulations were performed for different operating conditions of laser power, ambient pressure, and substrate traverse speed. Simulations revealed potential problems such as particle deflected away from substrate due to ambient air current disturbances, substrate overheating, and optical fiber clogging. Possible solutions for these problems are discussed

Using a combination of experiment and simulations, we have studied the equilibrium shapes of liquid microstructures on flat but chemically heterogeneous substrates. The surface patterns, which define regions of different surface energy, induce deformations of the liquid-solid contact line, which in turn can either promote or impede capillary break-up and bulge formation. We study numerically the influence of the adhesion energies on the hydrophilic and hydrophobic surface areas, the pattern geometry and the deposited fluid volume on the liquid surface profiles

We have developed a technique for the printing of copper lines using solutions of a metal organic precursor, copper hexanoate. A 500-µm written liquid line is observed to split into two 100-µm wide lines. We observe further splitting into four parallel lines in experiments with written lines of copper hexanoate solution in chloroform. Surface profiles indicate that the thickness, width and number of lines formed are strongly dependent on the solution viscosity and volume per unit length deposited. From particle tracking visualization and surface profiling, we have found that evaporative cooling produces Marangoni convection patterns that accrete the solute along two key boundaries of flow

Calculations of the Hamaker constants representing the van der Waals interactions between conductor, resistor and dielectric materials are performed using Lifshitz theory. The calculation of the parameters for the Ninham-Parsegian relationship for several non-aqueous liquids has been derived based on literature dielectric data. Discussion of the role of van der Waals forces in the dispersion of particles is given for understanding paste formulation. Experimental measurements of viscosity are presented to show the role of dispersant truncation of attractive van der Waals forces