Contents I. Introduction
As a representative of medium and low voltage power devices, shield gate trench metal-oxide-semiconductor field effect transistor (SGT MOSFET) has the advantages of low power loss and fast switching speed, which has become the mainstream choice in power applications below 200 V [1], [2], [3]. However, power devices including SGT MOSFET working in atmospheric and spacecraft applications are extremely sensitive to total-ionizing-dose (TID) radiation effects due to their direct exposure to various rays and high-energy particles, resulting in destructive performance degradation [4], [5], [6], [7], [8], [9], [10], [11], [12]. Previous studies about TID effects mainly focused on the conventional trench gate vertical double-diffused MOSFET (TMOS) [11], [12], but few of them addressed the TID radiation degradation mechanism of SGT MOSFET. According to the research of [10], SGT MOSFET not only exhibits the same threshold voltage () and leakage current shifts as the conventional TMOS but also shows significant breakdown voltage (BV) degradation after radiation. This is because the positive charges accumulated by the TID effects in the shield gate oxide sidewall destroy the original charge balance and change the electric field (-field) distribution in the drift region. However, there is no theoretical model that can accurately analyze the variation of E-field distribution caused by TID effects, and few hardened structures for SGT MOSFET.
