中文摘要：

在包含晶格加热和非本地传输的瞬态效应过程下，漂移-扩散模型（DD）不再有效，需采用更精确的非等温能量平衡（NEB）模型。NEB模型的计算结果表明，对于基区厚度处于DD模型向全量子输运模型过渡的缓变结HBT而言，晶格加热和非本地传输所起的作用是明显的，而基区重掺杂引起的带阶的扰动对缓变节HBT性能的影响则可以忽略。

英文摘要：

The transient effects for nonlocal transport and lattice heating are obvious in the graded HBTs with the thickness of its base in the transition describing by drift-diffusion （DD） approximation and full quantum mechanism, so the drift-diffusion （DD） approximations can lead to unacceptable inaccuracies in the predicted electrical characteristics of those devices. A more accurate carrier transport modeling named nonisothennal energy balance （NEB） was used for describing the perforce of HBTs. It is concluded that the nonlocal transport and lattice heating have an important impact on the device characteristics, and that band offset disturbance resulted from heavy-impurity of the base has little impact on the electrical characteristics of those devices.