Development of dodecahedron type MCP detector for SEM toward full energy range and solid angle electron detection.

Area of Science:

• Materials Science
• Surface Science
• Electron Microscopy

Background:

• Standard scanning electron microscopy (SEM) often captures limited directional electron information.
• Analyzing electron emission angles is crucial for understanding surface topography and material composition.

Purpose of the Study:

• To develop and evaluate a novel dodecahedral detector for SEM capable of multi-directional electron detection.
• To discriminate between backscattered electrons (BSE) and secondary electrons (SE) using bias grids.
• To assess the detector's performance in analyzing emission-angle dependence for various sample geometries.

Main Methods:

• Fabrication of a dodecahedral detector with microchannel plates (MCPs) mounted on its facets.
• Integration of bias grids for electron discrimination (BSE/SE).
• Imaging of diverse specimens (Cu plate, Cu-Al eutectic, stainless-steel sphere) using multiple detection angles (Top0, Up1, Up2, Down6).

Main Results:

• The detector successfully captured electrons from various directions, including upward and downward trajectories.
• SEM images revealed enhanced surface corrugations (Cu plate) and highlighted interfacial regions (Cu-Al) with specific angles.
• Downward BSE detection (Down6) proved effective for three-dimensional sample analysis (stainless-steel sphere).

Conclusions:

• The dodecahedral detector enables comprehensive analysis of electron emission-angle dependence without distorting electron trajectories.
• This multi-view approach simplifies signal handling and facilitates detailed, direction- and energy-resolved analysis of emitted electrons.
• The detector enhances SEM capabilities for characterizing complex surface topographies and microstructures.