Multi-physics Simulation Method And Its Application In Micro-nano Device Structures

With the continuous improvement of circuits’ integration, the traditional silicon-based devices would face greater parasitic capacitance and leakage current which drastically affect their normal operations. Meanwhile, the high density and high temperature will affect the devices’ performance, which brings the silicon material difficulties to further comply with the Moore’s Law. On the other hand, thanks to its unique advantages such as high breakdown voltage, excellent noise figure and high oscillation frequency, the gallium nitride material possesses the potential of being applied in military, aerospace, automotive and other related areas. For both traditional device and novel device, their reliability is becoming increasingly important for the development of next-generation semiconductor products. This article mainly focuses on the reliability of novel interconnects, laterally diffused metal oxide semiconductor field effect transistor (LDMOSFET) and AlGaN/GaN high electron mobility transistor (AlGaN/GaN HEMT). The main work and innovation of this paper are summarized as follows:Firstly, this article described the time-domain finite element method (TD-FEM), including its basic principles, mathematical foundations and implementation steps. The multi-physics simulation related differential equations are also introduced.Then, we developed the high frequency electrical characterization of Cu-graphene heterogeneous interconnects, and obtained its changing trends in accordance with the factors such as interconnects’ structure, and physical dimensions. The steady-state and transient characteristics of high-density multilayer Cu-graphene heterogeneous interconnect structure are simulated. The changing trend of temperature distribution and maximum temperature variation in interconnect arrays are analyzed and discussed in accordance with the excitations of different electro-static discharge (ESD) pulses, the change of maximum temperature response over graphene thickness is also explored.Next, the electro-thermo-mechanical simulations of LDMOSFET are performed. The variations of maximum temperature and maximum thermal stress are derived in accordance with the combined impulses’ forms and amplitudes.At last, the thermo-mechanical characteristics of high power GaN HEMT are investigated. On the basis, the diamond heat spreader is introduced, and its effects on GaN HEMT thermal management capability and thermal stress are studied in detail. This article is intended to provide a reference for devices’design process through simulations.