Impact of Parasitic Bipolar Effect on Single-Event Upset in p-Type Metal–Oxide–Semiconductor Field Effect Transistor with Embedded SiGe

Accelerated neutron tests for soft error rate (SER) are carried out using unbalanced feedback-loop circuits fabricated by Si and embedded SiGe (eSiGe) processes. The contribution of the p-type metal-oxide-semiconductor field effect transistor (PMOS) to total SER is shown to substantially decrease in the eSiGe process. The characteristics of parasitic bipolar transistors in PMOSs with and without eSiGe are investigated using technology computer-aided design (TCAD) simulations. We find that the narrow band gap of SiGe causes an increase in the rate of electron flow from the well region (Si) to the source region (SiGe), leading to a decrease in the current gain of the parasitic bipolar transistor in PMOS with eSiGe. Our results indicate that eSiGe can be attributed to the suppression of the parasitic bipolar effect, resulting in a reduced contribution of PMOS to SER. (C) 2013 The Japan Society of Applied Physics