论文部分内容阅读
采用解析的方法计算了在基区掺杂为高斯分布,Ge组分分布为三角形分布和矩形三角形分布时基区内建电场的变化情况.重新拟合了价带有效态密度公式,并在计算内建电场时考虑了导带有效态密度的影响.发现加入Ge组分后引起的导带有效态密度变化、价带有效态密度变化以及禁带宽度变窄量变化对基区内建电场的影响要大于掺杂对内建电场的影响.Ge组分为三角形分布时,在总的Ge组分一定的条件下,内建电场从发射结到集电结逐渐变大.在任一给定位置x处,内建电场随着Ge组分的增加而增大.当Ge组分分布为矩形三角形分布时,对于给定的Ge组分转折点x1,基区内建电场从发射结到集电结缓慢地增大.在Ge组分恒定的区域,内建电场变化甚微,在Ge组分为线性缓变区域的同一位置x处,内建电场随Ge组分转折点x1的增大而缓慢地增大.此外,在x1附近内建电场变化有一个很大的陡坡.
Analytical method was used to calculate the change of electric field in the base region when the base region was doped with Gaussian distribution, Ge component distribution was triangular and rectangular, and the effective density formula of valence band was recomputed. The influence of the effective density of conduction band is considered in the built-in electric field.It is found that the change of the effective density of conduction band, the effective density of valence band and the narrowing of the band gap, The effect is greater than the impact of doping on the built-in electric field.Ge component is triangular distribution, under the condition of the total Ge component, the built-in electric field gradually changes from the emitter junction to the collector junction gradually.At any given location x, the built-in electric field increases with the increase of Ge composition.When the distribution of Ge component is a rectangular triangular distribution, for a given Ge component turning point x1, the built-in electric field in the base region from the emitter junction to the collector junction Gradually increase in the Ge component constant region, the built-in electric field changes very little, in the Ge component linearly changing region at the same position x, the built-in electric field with Ge component turning point x1 slowly In addition, there is a big change in the built-in electric field near x1 steep slope.