多晶硅发射极微波功率管的三维热电耦合模型

3-D Thermal-electronic Coupled Modeling of Microwave Band Power Transistor with Polysilicon Emitter Structure

文章结合双层多晶硅发射极双极型微波功率管器件结构,采用步内建模法,首次建立了三维热电耦合模型,并进行了直流稳态模拟。模拟结果表明,新的三维热电耦合模型可准确预测功率管结温的均匀状况。与单子胞器件C1相比,多子胞器件C2的中心区域结温变化平缓,结温温度约为390K,比单子胞器件C1的结温温度下降约10K。此外,低热传导率的深槽结构有效地切断了相邻子胞之间的热电耦合效果,器件C2热源区与场氧区的温度差比器件C1大20K。因此,三维热电耦合模型对研制出高可靠性的双极型微波功率管提供了合理的理论依据。

A novel 3-D thermal-electronic coupled modeling is firstly put forward for fabricated bipolar microwave band power transistor with double layer polysilicon emitter structure. Based on the modeling, 3-D temperature distribution of the power device which is steady-state biased is numerically simulated. The results of simulation show that the device with multiple cells has lower average temperature compared with the device with single cell due to poor thermal conductivity for oxide refiller into deep trench. Hence the technique can improve the reliability of microwave bipolar transistor.