摘要
在对P^+-N结正向电容进行全面分析的基础上,本文提出了一种使P^+-N结正向势垒电容异常变化的掺杂分布模型,它的特点是:结电容在正向偏压下有比普通突变结快得多的变化速度和较大的变化幅度.把该模型应用于结电容为 0.08—0.25 pF的 GaAs参放变容管,结果表明,它提高了变容管的电容变化系数,并具有较高的零偏压截止频率,而且还降低了参放所需的泵功率.得到的样管参数为:零偏压截止频率400—700千兆赫、电容变化系数0.17-0.225,参放工作所需的泵功率仅10-20毫瓦.
On the basis of a complete analysis of P^+-N junction's forward capacitance, a newimpurity profile model that leads to an unusua change in P^+-N junction's forward bar-rier capacitance has been presented in this paper.The features of this model are: thechanged speed and amplitude of the junction cupacitance at forward bias are faster andlarger than those in the abrupt model.The new model is used in the fabrication of GaAsparametric varactor diodes with 0.08-0.25 pF. The results show that the capacitancevariation factor is increased, the higher zero-bias cutoff frequency is obtained and requir-ed pump power of parameter is decreased.The fabricated GaAs parametric varactorsexhibit zero-bias cutoff frequency of 400-700 GHz and capacitance variation factor of0.17-0.225.The parameter only needs the pump power of 10-20 mW.
