不同基区Ge组分分布对SiGe HBT特性的影响

Effects of Different Ge-Profiles in Base Region on Performance of SiGe HBT

研究了传统基区Ge组分分布(矩形分布、三角形分布、梯形分布)在210K～410K范围内对SiGe HBT特性的影响。借助TCAD工具进行实验,结果表明,在Ge杂质总量相同的情况下,器件的电流增益β,厄尔利电压VA,截止频率fT随着温度升高而降低;靠近基区发射结的Ge组分越高,β越大;基区Ge组分梯度升高,VA增大,fT增大。提出了一种优化的Ge分布,与传统Ge分布相比,该分布器件的电流增益β对温度的敏感性分别降低72.1%,56.4%和58.7%,扩大了器件的应用领域。

Effects of conventional Ge profiles （box, triangle, trapezoidal） in the base region on performance of SiGe HBT in the temperature range between 210 K to 410 K were investigated. Results from experiments with TCAD showed that, for the same amount of Ge, the current gain β, Early voltage VA and cutoff frequency fT decreased with increasing temperature. The fl was improved with increasing Ge profile near EB junction,and theVA and fT were improved with increasing Ge gradient. An optimal Ge profile was proposed, which reduced temperature sensitivity of current gain by 72. 1%,56. 4% and 58. 7%, compared with the conventional Ge profile.