A novel pixellated solid-state photon detector for enhancing the Everhart-Thornley detector

Area of Science:

• Physics
• Electrical Engineering
• Materials Science

Background:

• The Everhart-Thornley detector is a standard component in scanning electron microscopes.
• Existing detectors face limitations in terms of size, power consumption, and integration capabilities.

Purpose of the Study:

• To develop and characterize a novel pixellated solid-state photon detector.
• To improve upon the performance and integration of current secondary electron detectors.
• To enable advanced imaging and analysis in scanning electron microscopy.

Main Methods:

• Fabrication using Austriamicrosystems 0.35 µm complementary metal-oxide-semiconductor (CMOS) process technology.
• Integration of high-responsivity photodiodes, low-noise transimpedance amplifiers, a selector-combiner circuit, and a variable-gain postamplifier.
• Performance evaluation through simulations and experimental measurements.

Main Results:

• Achieved maximum transimpedance gain of 170 dBΩ and minimum bandwidth of 3.6 MHz.
• Demonstrated detection of optical signals as low as 10 nW.
• Minimum signal-to-noise ratio (SNR) of 24 dB achieved, independent of gain settings.
• Successful pixel selection and signal combination demonstrated.
• Key advantages include smaller size, cost-effectiveness, lower power/voltage needs, and enhanced integration.

Conclusions:

• The developed pixellated solid-state photon detector offers significant advantages over existing technologies.
• Pixel-selection configurability enhances SNR and enables image generation for diverse analyses.
• This work advances system-level integration of detectors for scanning electron microscopy.