中文摘要：

传统的宏观传热理论难以准确表征几何结构尺度小于或接近声子平均自由程的高功率电子器件的产热与传热过程,此时器件中能量激发的时间尺度与声子的特征时间尺度相当,甚至小于声子的特征时间尺度,不能满足传统传热理论的假设.本文针对微/纳尺度场效应晶体管的工作过程,建立描述其内部产热及传热特性的多尺度格子-Boltzmann介观模型,通过在模型中引入源项去描述器件内部电子和声子的相互作用,分析计算不同工作状态下晶体管单元的温度分布特征,研究热管理方式对晶体管温度分布的影响,从微/纳尺度揭示了场效应晶体管的产热机理及传热特性,为热设计工作者提供一定的理论依据.

英文摘要：

Traditional macroscopic method is incapable of describing the heat generation and transfer mechanism in high-power electronic devices, when either characteristic dimensions become comparable or less than the mean free path of phonons ,or characteristic timescale of devices equals to or smaller than the relaxation time of phonons. In order to reveal the heat generation and transfer mechanism in micro/nano-scale devices, a multiscale lattice Boltzmann modeling of field effect transistor （FET） with different conditions is proposed. In this model, a source term is introduced to describe the scattering of phonons and electrons. Under different working conditions and thermal managements （such as the location of hot spot, peak value of temperature, average temperature）,the temperature distribution of a FET is investigated. By analyzing heat generation and transfer mechanism of FET in micro/nano-scale, it provides theoretical reference to engineers.