Reliability of power transistors in radiation environments

• Ano de defesa: 2025
• Autor(a) principal: Alberton, Saulo Gabriel Pereira Nascimento
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: dipositivos eletrônicos; efeitos de radiação; electronic devices; interação da radiação com a matéria; radiation effects; radiation interaction with matter; single-event burnout; single-event effects
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/43/43134/tde-20052025-195023/

Electronic devices are vulnerable to failures and adverse effects when operating in radiation environments, such as outer space and even the Earth\'s atmosphere. In space, heavy ions are the primary cause of destructive radiation effects in electronic devices, whereas, on Earth, neutrons are the main cause of natural radiation effects at flight altitudes and ground level. Power transistors are essential components of modern electronics and are particularly prone to destructive radiation effects due to their intense internal electric fields. The modern UMOSFET (U-groove Metal-Oxide-Semiconductor Field-Effect Transistor) technology is currently one of the most widely used semiconductor power devices worldwide, gradually replacing the traditional DMOSFET (Double-diffused MOSFET) technology due to its superior electrical performance. However, ensuring the radiation hardness of UMOS technology is crucial before its incorporation in high-reliability applications, such as in space, avionics, or autonomous vehicles. This study presents a comparative experimental and computational analysis of ion- and neutron-induced radiation effects on Si-based UMOS and DMOS power transistors. For space applications, transistors with similar voltage ratings were irradiated with alpha particles and heavy ion beams. For high-reliability atmospheric applications, similarly rated transistors were exposed to monoenergetic and quasi-atmospheric neutron beams, i.e., which replicate the energy spectrum of atmospheric neutrons. The main charge collection mechanisms, responses to non-destructive radiation effects, and vulnerabilities to destructive radiation effects are directly compared. Unlike SiC-based transistors and contrary to prior computational studies, experimental results reveal that Si-based UMOSFETs exhibit premature avalanche multiplication compared to DMOSFETs, favoring the occurrence of destructive radiation effects. Based on experimentally validated computational results, strategies are proposed to enhance the reliability of next-generation UMOSFETs. Moreover, an existing model for predicting worst-case ion-induced destructive effects, commonly adopted as a qualification protocol for power devices tested with particle accelerators, is refined and extended into a universal mathematical formulation. The proposed model encompasses various semiconductor materials relevant for power electronics applications, including Si, SiC, GaAs, GaN, Ge, and diamond. The improved model is experimentally validated across different power transistor technologies, demonstrating superior accuracy than the previous model when compared to experimental data.