Benzethonium chloride as a tungsten corrosion inhibitor in neutral and alkaline media for the post-chemical mechanical planarization application.

The cleaning solution for the post-chemical mechanical planarization (post-CMP) process of tungsten in neutral-alkaline media requires corrosion inhibitors as an additive, especially for advanced devices where the device node size shrinks below 10 nm. In the present study, the corrosion inhibition performance of benzethonium chloride (BTC) is evaluated in neutral-alkaline conditions. The electrochemical impedance spectroscopy (EIS) analysis showed ∼ 90 % of corrosion inhibition efficiency with an optimum concentration of 0.

Chemically controlled megasonic cleaning of patterned structures using solutions with dissolved gas and surfactant.

Acoustic cavitation is used for megasonic cleaning in the semiconductor industry, especially of wafers with fragile pattern structures. Control of transient cavitation is necessary to achieve high particle removal efficiency (PRE) and low pattern damage (PD). In this study, the cleaning performance of solutions with different concentrations of dissolved gas (H) and anionic surfactant (sodium dodecyl sulfate, SDS) in DIW (DI water) on silicon (Si) wafers was evaluated in terms of PRE and PD.

Large-scale plasma patterning of transparent graphene electrode on flexible substrates.

Graphene, a two-dimensional carbon material, has attracted significant interest for applications in flexible electronics as an alternative transparent electrode to indium tin oxide. However, it still remains a challenge to develop a simple, reproducible, and controllable fabrication technique for producing homogeneous large-scale graphene films and creating uniform patterns with desired shapes at defined positions. Here, we present a simple route to scalable fabrication of flexible transparent graphene electrodes using an oxygen plasma etching technique in a capacitively coupled plasma (CCP) system.

Effect of dissolved gases in water on acoustic cavitation and bubble growth rate in 0.83 MHz megasonic of interest to wafer cleaning.

Changes in the cavitation intensity of gases dissolved in water, including H2, N2, and Ar, have been established in studies of acoustic bubble growth rates under ultrasonic fields. Variations in the acoustic properties of dissolved gases in water affect the cavitation intensity at a high frequency (0.83 MHz) due to changes in the rectified diffusion and bubble coalescence rate.

Wafer-scale nanowell array patterning based electrochemical impedimetric immunosensor.

We have reported that nanowell array (NWA) can enhance electrochemical detection of molecular binding events by controlling the binding sites of the captured molecules. Using NWA biosensor based amperometric analysis, we have detected biological macromolecules such as DNA, protein or aptamers at low concentrations. In this research, we developed an impedimetric immunosensor based on wafer-scale NWA for electrochemical detection of stress-induced-phosphoprotein-1 (STIP-1).

Quantitative analysis of H5N1 DNA hybridization on nanowell array electrode.

A nanowell array electrode-based electrochemical quantitative system without amplification was developed and applied for the detection of H5N1 target DNA. An 18-mer probe was immobilized on a nanowell array electrode with a diameter of 500 nm, which was coated with streptavidin and a self-assembly monolayer (SAM). The surface properties of probe DNA hybridization with complementary target DNA were characterized using atomic force microscopy (AFM) and electrochemical impedance spectroscopy (EIS).

Detection of single nucleotide polymorphisms using a biosensor-containing titanium-well array.

The rapid identification and verification of single nucleotide polymorphisms (SNPs) were demonstrated using a well array sensor containing anti-biofouling titanium (Ti). Probe single-stranded DNA (ssDNA) was immobilized inside a titanium-well array on amine-modified glass surfaces with anti-biofouling behavior via a streptavidin-biotin interaction. Fluorescence intensity changes originating from the hybridization of nucleic acids to protein-bound nucleic acids linked to Alexa Fluor (FL) 647 were observed.

A self-assembled monolayer-based micropatterned array for controlling cell adhesion and protein adsorption.

We developed a surface micropatterning technique to control the cell adhesion and protein adsorption. This micropatterned array system was fabricated by a photolithography technique and self-assembled monolayer (SAM) deposition. It was hypothesized that the wettability and functional terminal group would regulate cell adhesion and protein adsorption.

Synthesis of Fe metal precipitated colloidal silica and its application to W chemical mechanical polishing (CMP) slurry.

The objective of this paper is to develop a new method of Fe (metal) precipitation on colloidal silica to overcome the stability problem, which would be responsible in producing defects, with commercially available fumed silica slurry containing Fe ions. The slurry was developed by using sodium silicate (Na(2)SiO(3)) as a raw material and the concentration of precipitation of metal was controlled by addition of Fe salt (Fe(NO(3))(3)). To compare the concentration of precipitated Fe with directly added Fe ions in slurry solutions, static electrochemical and peroxide decomposition experiments were performed.

Collapse behavior and forces of multistack nanolines.

Two types of multistack nanolines (MNLs), Si-substrate (Si)/siliconoxynitride (SiON)/amorphous Si (a-Si)/ SiO(2) and Si/ SiO(2) /polycrystalline Si (poly-Si)/ SiO(2) were used to measure the collapse force and to investigate their collapse behavior by an atomic force microscope (AFM). The Si/SiON/a-Si/ SiO(2) MNL showed a larger length of fragment in the collapse patterns at a smaller collapse force. The Si/ SiO(2) /poly-Si/ SiO(2) MNL, however, demonstrated a smaller length of fragment at a higher applied collapse force.

Convective assembly and dry transfer of nanoparticles using hydrophobic/hydrophilic monolayer templates.

A convective directed-assembly process on a flat substrate that does not require motion and is followed by a dry-transfer process of nanoparticles is presented. The convective assembly process was achieved using Au nanoparticles on hydrophobic/hydrophilic-surface-patterned Si substrates as functions of temperature, gap height, and particle size. An investigation of the particle assembly mechanism showed that the effects of temperature, gap height, and particle size were responsible for controlling the evaporation time, the evaporation length, and the assembly speed, respectively.

Development of inlaid electrodes for whole column electrochemical detection in HPLC.

An electrochemical microfluidic device has been fabricated on PET (polyethylene terephthalate) substrate using an imprinting method. The imprinting transfers patterns from a stamp into a substrate mechanically. However, a blanket mould imprinting process has been introduced to embed the photolithographically produced gold metal electrode lines into the PET substrate resulting in an individually addressable array flush to better than 100 nm.

Fabrication of nano- and micro-scale UV imprint stamp using diamond-like carbon coating technology.

Two-dimensional (2-D) and three-dimensional (3-D) diamond-like carbon (DLC) stamps for ultraviolet nanoimprint lithography were fabricated with two methods: namely, a DLC coating process, followed by focused ion beam lithography; and two-photon polymerization patterning, followed by nanoscale-thick DLC coating. We used focused ion beam lithography to fabricate 70 nm deep lines with a width of 100 nm, as well as 70 nm deep lines with a width of 150 nm, on 100 nm thick DLC layers coated on quartz substrates. We also used two-photon polymerization patterning and a DLC coating process to successfully fabricate 200 nm wide lines, as well as 3-D rings with a diameter of 1.