多指PHEMT器件热点和热阻数值研究

A Numerical Study on the Hot Spot and Thermal Resistance of Multi-Finger PHEMTs

随着大功率半导体器件的发展,其局部热流密度急剧增加。为防止器件功能失效,需要可靠的建模技术来研究器件的热学行为,进而指导其冷却设计。本文采用非等温能量平衡模型研究了自热效应对栅长为500nm的多指GaAs赝配高电子迁移率固态微波功率器件(PHEMT)的热学特性的影响。基于泊松方程、连续性方程、输运方程和晶格热方程,数值求解得到了器件的热点位置和温度分布,并通过实验进行了验证。最后,应用(?)理论,进-步分析了(?)耗散热阻在评价器件热学性能方面的适用性。

With the development of high power semiconductor devices,the local heat flux of a device is increasing dramatically.In order to avoid the device failure,reliable modeling techniques are needed to study the thermal behavior of the devices for further cooling designs.In this paper,the non-isothermal energy balance model is applied to investigate the effect of the self-heating on the thermal characteristics of multi-finger GaAs pseudomorphic high-electron-mobility transistors(PHEMTs) with the gate length of 500 nm.The location of the hot spots and the temperature distribution of the device are obtained by a numerical simulation based on the Poisson's equation,the continuity equations and energy balance equations for electrons and holes,and the thermal diffusion equation for lattice.Moreover,the numerical simulation results are verified by experiments.Finally,the applicability of the entransy-theory-based thermal resistance to the evaluation of the thermal performance of PHEMTs is analyzed.