Creation of highly functional thin films using electrochemical nanotechnology

Abstract

This overview describes the results of our recent study of the application of electrochemical nanotechnology to the fabrication of magnetic recording materials, interconnects in ultra-large-scale integrated (ULSI) devices, energy storage materials, and on-chip biosensors. It is important to note that electrochemical processes play significant roles in developing and fabrication such sophisticated materials and devices. In the field of magnetic recording, electrodeposition methods for preparing CoNiFe and CoFe soft magnetic thin films with a high saturation magnetic flux density were newly developed, and the significant issues for obtaining those films are highlighted. In the area of ULSI interconnects, we developed a technique using a self-assembled monolayer (SAM) for direct bonding of the interconnect layer to SiO2, and proposed a novel electroless deposition method for fabricating a diffusion barrier layer. In the field of batteries, electrodeposited SnNi alloy was proposed as a future anode material for Li batteries, and electrochemical MEMS processes were shown to be useful for fabricating micro-sized direct methanol fuel cells (DMFCs) as portable batteries for electronics applications. In the area of chemical sensors, we developed a new process for fabricating field effect transistors (FETs) modified with SAMs for on-chip biosensing applications.

Effects of nanostructured, diamondlike, carbon coating and nitrocarburizing on the frictional properties and biocompatibility of orthodontic stainless steel wires

“…Surface nanoengineering might enhance both the surface properties and performance of materials by changing surface organization and structure. 25 In this study, we successfully deposited even and dense nanostructured DLC films onto orthodontic stainless steel archwires. The ultrafine grains and wider atomic spacing resulting from the nanostructured DLC films, provided excellent characteristics compared with traditional archwires.…”

Achievement of Bottom-Up Electroless Nickel Filling on the SiO2 Surface with Pd-Activated SAM

“…13,14 When the SiO 2 substrates were immersed in solution of APS, APS molecules are bonded to the SiO 2 surface by a silane coupling reaction, leading to the formation of SAM. When the modified substrates were immersed into a PdCl 2 solution (0.1 g dm −3 ) for 30 s, the Pd 2+ ions were absorbed on the surface of the SAM with coordination of amino groups.…”

“…Subsequently, the substrate was rinsed in methanol with ultrasonication to eliminate the extra silane. After forming the SAM, the SAM was z E-mail: wangzl@snnu.edu.cn modified by activation in a PdCl 2 (0.1 g dm −3 of PdCl 2 in dilute HCl) solution for 30 s. 13,14 Finally, the substrates were pretreated with DMAB for 2 min to reduce Pd 2+ into Pd, rinsed in ultrapure water, and then immersed into the electroless nickel plating bath. After the electroless nickel deposition, the filling feature of trenches was examined by a field-emission scanning electron microscope (FE-SEM, JSM-6700 F).…”

Electrochemically Fabricated Microelectromechanical Systems/Nanoelectromechanical Systems (MEMS/NEMS)

“…Currently, electroless materials for MEMS and Ultra Large Scale Integration (ULSI) include Cu, Co, Ni, Ag, and their alloys [18]. The uniform films, nanometersize crystals, and ability to coat nonconducting materials have allowed the use of electroless deposits for interconnects, barrier layers, packaging, and potential nanoelectronics [19].…”