Design of Pixellated CMOS Photon Detector for Secondary Electron Detection in the Scanning Electron Microscope

Abstract

This paper presents a novel method of detecting secondary electrons generated in the scanning electron microscope (SEM). The method suggests that the photomultiplier tube (PMT), traditionally used in the Everhart-Thornley (ET) detector, is to be replaced with a configurable multipixel solid-state photon detector offering the advantages of smaller dimension, lower supply voltage and power requirements, and potentially cheaper product cost. The design of the proposed detector has been implemented using a standard 0.35 μm CMOS technology with optical enhancement. This microchip comprises main circuit constituents of an array of photodiodes connecting to respective noise-optimised transimpedance amplifiers (TIAs), a selector-combiner (SC) circuit, and a postamplifier (PA). The design possesses the capability of detecting photons with low input optical power in the range of 1 nW with 100 μm × 100 μm sized photodiodes and achieves a total amplification of 180 dBΩ at the output.

Shedding Light on Cardiac Excitation: In Vitro and In Silico Analysis of Native Ca2+ Channel Activation in Guinea Pig Cardiomyocytes Using Organic Photovoltaic Devices

“…We used a photodiode equivalent circuit to model the behavior of the OEPC device (see Fig. A.1) [40] in response to light stimulation. The interface to the bath electrolyte was defined as a complex impedance using a weak contribution boundary condition with Rf = 2.514 Ωm 2 and C=0.1 F/m 2 .…”

A novel pixellated solid‐state photon detector for enhancing the everhart–thornley detector

“…The target bandwidth of the photon detector is 3.5 MHz, which is sufficient for this type of application. Circuit design and implementation of the subblocks have been presented in detail (Chuah and Holburn, ).…”