Single Event Effect Testing of Commercial Silicon Power MOSFETs

Silicon Power MOSFETs, devices designed to handle significant power levels, are widely used as parts of power management electronic systems, distributed along the CERN accelerator complex. However, irradiation can compromise their performance, as under certain bias conditions they are particularly sensitive to destructive Single Event Effects (SEE), caused by a single ionizing particle randomly passing through the sensitive regions of the device. These effects can be distinguished in Single Event Burnouts (SEB) and Single Event Gate Ruptures (SEGR), both of which lead to the complete failure of the power MOSFET and hence of the system in which it is embedded. The present thesis is devoted to the experimental evaluation of the SEE sensitivity of commercial power MOSFETs, as well as to the study of the effect of certain param- eters, related to the device itself (biasing, operational characteristics, technology) and to the irradiation conditions (particle type, energy, LET). For the experimental tests, which involve the irradiation of MOSFETs with beams of energetic particles, a setup that allows for the detection, counting and saving of the SEB-generated pulses, while protecting the devices from catastrophic failure, has been employed. Recent modifications on the test setup have enabled the distinction between SEBs and SEGRs, as well as the on-line characterization of the samples. Irradiation campaigns have been carried out in a variety of European facilities and involved the exposure of power MOSFETs to high energy proton beams, neutrons with an atmospheric-like spectrum, a mixed-field that is representative of the high- energy accelerator spectra, and lastly to heavy ions of different type and energy. The tested commercial power MOSFETs were selected among candidates interesting for CERN accelerator applications, including parts of different manufacturers and rated voltage capabilities. A detailed compilation of the results obtained, along with relevant comparisons and observations, is included in the thesis. Keywords: power MOSFETs, Single Event Burnout (SEB), Single Event Gate Rupture (SEGR), non-destructive, protons, neutrons, heavy ions