Elastomeric stamps facilitate direct patterning of electrical, biological, chemical, and mechanical materials A thin film of material is deposited on a substrate The deposited material, either originally present as a liquid or subsequently liquefied, is patterned by embossing at low pressure using an elastomeric stamp having a raised pattern The patterned liquid is then cured to form a functional layer The deposition, embossing, and curing steps may be repeated numerous times with the same or different liquids, and in two or three dimensions The various deposited layers may, for example, have varying electrical characteristics, interacting so as to produce an integrated electronic component

Fabrication of finely featured devices by liquid embossing

Ceramic integration technology requires downsizing and/or improvement of device performance in many applications, such as in the fabrication of microelectromechanical systems, display devises, fuel cells, optical devices, and RF components. For these applications, realization of high-speed deposition rate, low process temperature, and fine patterning in ceramic coating are very important. The aerosol deposition (AD) method has many advantages for above requirements in comparison with conventional thin-film method or thermal spray coating technology. In this article, advantages of the AD method are highlighted by realizing a comparison with conventional thin-film methods and thermal spray technology. Challenges associated with AD method are also highlighted. At the end, examples of integration of AD method in the fabrication of electronic components are also given to show the easiness in usage and in integration of this method in the device process flow.

Room Temperature Impact Consolidation (RTIC) of Fine Ceramic Powder by Aerosol Deposition Method and Applications to Microdevices

Silicon nanowires for advanced energy conversion and storage

A metal nanoparticle composition for the fabrication of conductive features. The metal nanoparticle composition advantageously has a low viscosity permitting deposition of the composition by direct-write tools. The metal nanoparticle composition advantageously also has a low conversion temperature, permitting its deposition and conversion to an electrical feature on polymeric substrates.

Metal nanoparticle compositions

Nanosilicon anodes for high performance rechargeable batteries

The diameter of particles which adversely affects the yield has been shrinking as ULSI devices are more and more miniaturized. Ultrafine particles with diameters of 0.1 μm or less have become important recently. Ultrafine particles of this type are expected to be difficult to remove. This study has established a method to evaluate ultrafine particle removal efficiency. Ultrafine metallic particles with diameters of several to several hundreds of nanometers were deposited on the Si surface using a gas deposition method. The removal efficiency of the ultrafine particles using various cleaning solutions was investigated. APM (NH 4 OH-H 2 O 2 -H 2 O) cleaning can remove 150 nm Au particles, but cannot remove ultrafine Au particles with a diameter less than several tens of nanometers. In addition, the Si surface becomes rougher when a DHF-H 2 O 2 cleaning is performed to remove Au ultrafine particles. This is believed to be because noble metals such as Au, Ag, and Cu, which feature a higher electronegativity than Si, attract electrons from Si facilitating Si oxidation

Behavior of Ultrafine Metallic Particles on Silicon Wafer Surface

Ultrafine particles having diameters in the range larger than 1 nm and less than 1 μm can be called nanoparticles. Chemically pure nanoparticles are usually produced by evaporation and condensation in a controlled environment. Scientific engineers may consider nanoparticles as materials suitable for the fabrication of micrometer-sized elements of macroproducts, while scientists consider the atomic and electronic structure and properties of nanoparticles. We previously proposed a deposition and/or erosionn process called the gas deposition process, where nanoparticles entrained in a tiny carrier gas jet collide and are deposited onto a target substrate ( Jpn. J. Appl. Phys., 23 (1984) L910–L912). The electrical circuit pattern (approximately 40 μm width), the capacitor (BaTiO 3 ), oxide superconducting contacts (yttrium, bismuth) etc. are exapmles of components of the process. Analysis of the thermal behavior of nanoparticles during the process will be discussed. We believe that this process or any other pollution-free and localized process should be developed as a bridging technology between the macro and atomic worlds.

The use of nanoparticles as coatings

A metal paste comprising ultrafine particles of a metal. The particles have a particle size of 1000 angstroms (0.1 micron) or less and are individually uniformly dispersed in an organic solvent. A process for producing a metal paste comprises the steps of evaporating a metal in a vacuum chamber in an atmosphere of an inert gas at a pressure of 10 Torr or less and of collecting the vapor of the evaporated metal on a cooling surface in the form of ultrafine particles having a particle size of 1000 angstroms (0.1 micron) or less, wherein a vapor of an organic solvent is introduced into the vacuum chamber while the metal is being evaporated. A method for preparing a metallic thin film having a thickness of between 0.01 micron and 1 micron uses a metal paste containing ultrafine metal particles having a diameter of 0.1 micron or less uniformly dispersed in an organic solvent. In the method, the metal paste is coated on a substrate, dried and sintered.

Process for making a thin film using a metal paste

A metal paste comprising ultrafine particles of a metal. The particles have a particle size of 1000 angstroms (0.1 micron) or less and are individually uniformly dispersed in an organic solvent. A process for producing a metal paste comprises the steps of evaporating a metal in a vacuum chamber in an atmosphere of an inert gas at a pressure of 10 Torr or less and of collecting the vapor of the evaporated metal on a cooling surface in the form of ultrafine particles having a particle size of 1000 angstroms (0.1 micron) or less, wherein a vapor of an organic solvent is introduced into the vacuum chamber while the metal is being evaporated. A method for preparing a metallic thin film having a thickness of between 0.01 micron and 1 micron. A metal paste containing ultrafine metal particles having a diameter of 0.1 micron or less uniformly dispersed in an organic solvent is coated on a substrate, dried and sintered.

Metal paste, process for producing same and method of making a metallic thin film using the metal paste

Ultra fine particles (UFP) of organic and inorganic materials can be formed by the gas evaporation method (gas condensation method). In the gas deposition method, particles formed by the gas evaporation method in an evaporation chamber are carried to another chamber (a deposition chamber) through a pipe. Particles are accelerated in the pipe with a gas flow and come out of a nozzle located in the deposition chamber which is being evacuated down to less than 10 torr and deposited on a substrate to form UFP films. The final speed of the particles depends on the pressure difference between the evaporation chamber and the deposition chamber. The particles speed exceeds 500m/s and adhesion strengths of the films reach 500Kgf/cm2 as well as vacuum deposition films in the condition that the pressure of the evaporation chamber is at 4 atms. Patterns of spots and lines with 50 μm size and also wider films can be formed on a substrate without a masking system. The process is effective for repairing electric connecting lines or producing electrodes and condensers on an industrial scale.

Masaaki Oda

Papers

Behavior of Ultrafine Metallic Particles on Silicon Wafer Surface

The use of nanoparticles as coatings

Process for making a thin film using a metal paste

Metal paste, process for producing same and method of making a metallic thin film using the metal paste

Ultra Fine Particle Films by Gas Deposition Method