Abstract The localized high temperature generated during the operation of power devices is one of the main factors affecting their performance and lifetime. With the rapid development of devices towards miniaturization and high integration, this local hotspot phenomenon becomes more and more significant, which poses a serious threat to the reliability of devices. In this work, the thermal behavior of n-MOSFET is investigated through experiments during operation, and non-uniform high temperature hotspots are found to occur easily. In order to effectively suppress the localized high temperature and improve the device reliability, three innovative thermal regulation strategies are proposed: gradient doping (EID and LID), integrated graphene (GRA), and the synergistic application (LID + GRA). The thermal regulation effect of each strategy is analyzed using simulation. The results show that the gradient doping strategy significantly reduces the heat generation inside the device by optimizing the doping distribution, thus effectively controlling the overall temperature, especially for LID. In addition, introducing graphene with high thermal conductivity and electrical conductivity can considerably reduce the average temperature and mitigate the localized hotspots between the gate and source regions, especially the two layers of graphene. Critically, the synergistic effect of gradient doping (LID) and graphene integration shows excellent advantages in optimizing the electro-thermal performance, achieving a comprehensive thermal management performance that is difficult to be achieved by a single strategy. This study provides new ideas for future thermal management of power devices.
Zhang et al. (2026) studied this question.