Imaging and Dopant Profiling of Silicon Carbide Devices by Secondary Electron Dopant Contrast

Monte Carlo simulation of emission site, angular and energy distributions of secondary electrons in silicon at low beam energies

“…5a shows the MC simulation of the signal acquired in a silicon PN junction at a PE energy of 0.5 keV. As already confirmed by previous experimental measurements [1], the p-type doped anode exhibits a SE yield, which exceeds the SE yield of the cathode, as well as the SE yield of the n-typed doped cathode. Fig.…”

“…In both cases, the SEPC is due to the dependence of the SE yield on the local surface potential related to the local carrier density, and finally to the macroscopic doping concentration [1]. Theoretically, a contrast could also arise due to energy dependence of the emerging angles of the SE.…”

“…The physics of the contrast generation in semiconductor has been investigated in several works [1]. In bipolar junctions, the contrast between anode and cathode arises because of the built-in potential V bi given by…”

“…Besides traditional imaging, SE scanning electron microscopy is used increasingly for two-dimensional mapping of dopants in semiconductor devices by secondary electron potential contrast spectroscopy [1], for metrology purposes, as well as for threedimensional image reconstruction by steroscopic techniques [2]. In modeling these applications, the prediction of the site of emission of SE, of the energy, as well as the emerging angle is of paramount importance.…”

Characterization of photonic devices by secondary electron potential contrast

“…The benefits for SEPC deriving from the operation at low acceleration voltages have been already discussed in a previous work [4]. Among these, the fact that finest sample details can be resolved and that the charging effects are minimized.…”