Mid Sweden University

Electron detection at low energy range for scanning electron microscope (SEM), electron capture detector and electron probe micro-analysis (EPMA) applications, require detectors with high sensitivity and accuracy for low energy range. Such detectors must therefore have a thin entrance window and low recombination at the Si-SiO2 interface. An electron detector with 100 photons to electron-hole pair production rate having a 10 nm SiO2 passivating layer reveals a responsivity of approximately 0.25 A/W when irradiated. Simulations results showing the responsivity of electron interaction between detectors of varied interface fixed oxide charge density Qf show that there is an appreciable difference with the responsivity of a p +n detector and that of an n+p. The simulation results also show the significance of the effect of the minority carriers transport velocity Sn,p on the responsivity of the detector. © 2011 IOP Publishing Ltd and SISSA.

Surface states and interface recombination velocity that exist between detector interfaces have always been known to affect the performance of a detector. This article describes how the detector performance varies when the doping profile is altered. When irradiated with electrons, the results show that while changes in the doping profile have an effect of the detector responsivity with respect to the interface recombination velocity

Vs, there is no visible effect with respect tofixed oxide charge

Qfotherwise known as interface fixed charge density.

This paper explores an alternative to the standard method of studying the responsivities (the input—output gain) and other behaviours of detectors at low electron energy. The research does not aim to compare the results of differently doped n⁺p detectors; its purpose is to provide an alternative characterization method (using scanning electron microscopy) to those used in previous studies on the responsivity of n⁺p doped detectors as a function of the electron radiation energy and other interface parameters.