Highly reproducible secondary electron imaging under electron irradiation using high-pass energy filtering in low-voltage scanning electron microscopy.

The reproducibility of contrast in secondary electron (SE) imaging during continuous electron irradiation, which caused surface contamination, was investigated using SE high-pass energy filtering in low-voltage scanning electron microscopy (SEM). According to high-pass energy-filtered imaging, dopant contrast in an indium phosphide remained remarkably stable during continuous electron irradiation although the contrast in unfiltered SE images decreased rapidly as a contamination layer was formed. Charge neutralization and the SE energy distributions indicate that the contamination layer induces a positive charge.

Energy-filtered imaging in a scanning electron microscope for dopant contrast in InP.

We demonstrate that energy-filtered secondary electron (SE) imaging can be used effectively to observe dopant contrast from an InP surface covered with a contamination layer formed by continuous electron irradiation. Although dopant contrast from a surface covered with a contamination layer was almost invisible in a normal SE image, it was still clearly seen in the energy-filtered image. The contrast mechanism is explained in terms of a metal-semiconductor contact charging model and energy shift between the SE distributions across p-type and n-type regions.

Adsolubilization of 2-naphthol into adsorbed layers of triblock PEO-PPO-PEO copolymers on hydrophobic silica particles.

Adsolubilization of 2-naphthol into an adsorbed layer of triblock poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO, Pluronics) copolymers on hydrophobically modified silica particles has been investigated. Four kinds of Pluronics (P103, P105, P123, and F108) were employed in order to understand the effect of the hydrophobicity of the surfactants on the adsolubilization. The amount of the Pluronics adsorbed of the maximum/saturation adsorption level was increased with a decrease in the HLB value, suggesting that the more hydrophobic Pluronics (P103 and P123) adsorb preferentially onto the hydrophobic silica surface over the more hydrophilic Pluronics (P105 and F108).

Adsolubilization of 2-naphthol into adsorbed layer of PEO-PPO-PEO triblock copolymers on hydrophilic silica.

Adsolubilization of 2-naphthol into an adsorbed layer of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers (Pluronics) on hydrophilic silica has been investigated. Four kinds of Pluronics (P103, P105, P123, and F108) were used in order to understand the effect of the hydrophobicity of surfactant on the adsolubilization. The order of the adsorption in the saturation level was found to be P123 approximately P103 > P105 >> F108, meaning that Pluronics with higher hydrophobicity can adsorb preferentially to the silica surface.