Electron detection in the intermediate chamber of the variable pressure SEM

Area of Science:

• Materials Science
• Physics

Background:

• Variable pressure scanning electron microscopy (VP-SEM) requires efficient secondary electron detection across a wide pressure range.
• Existing detector designs may have limitations in complexity, vacuum requirements, or physical dimensions.

Purpose of the Study:

• To discuss and compare two concepts for secondary electron detection within the intermediate chamber of VP-SEM.
• To introduce and evaluate an improved intermediate secondary electron detector.

Main Methods:

• Comparative analysis of two secondary electron detector concepts.
• Utilizing MC-SIMION software for computer simulations of electron and ion flow.
• Simulations modeled charged particle trajectories in electric and magnetic fields.

Main Results:

• The intermediate secondary electron detector presents an improved solution regarding complexity, vacuum demands, and dimensions.
• Both detector systems, employing scintillators, function effectively from high vacuum to pressures exceeding 10 mbar.
• Computer simulations validated the detector functioning by illustrating electron and ion flow dynamics.

Conclusions:

• The intermediate secondary electron detector offers enhanced performance and practicality for VP-SEM applications.
• Scintillator-based detectors are viable for secondary electron detection in VP-SEM across a broad pressure spectrum.
• MC-SIMION simulations are a valuable tool for understanding and optimizing detector performance.