穿通增强型硅光电晶体管的结构及参数优化

为克服各种常用光电探测器件的缺点, 对穿通增强型硅光电晶体管进行了结构优化和参数优化。将窄基区穿通晶体管仅在一侧与宽基区光电晶体管复合的传统结构, 改进为窄基区穿通晶体管在中间, 两侧各复合一个长度减半的宽基区光电晶体管。同时, 对不同窄基区宽度下的暗电流、 光生电流及光电响应率等随偏压变化的电学性能和光电转换特性进行仿真, 得到窄基区宽度最优参数。然后对优化后的器件在不同光强下的光生电流和光电响应率随偏压的变化进行了仿真, 分析了器件在不同光强下的响应特性。结果表明, 当窄基区宽度为0.6 μm时, 器件性能折中达到最优, 在0.5 V偏压下, 器件暗电流仅为1 μA；入射光功率密度为10^-7 W/cm²时, 器件响应率高达4×10⁶ A/W。

Structure and Parameters Optimization of Punchthrough Enhanced Phototransistor

We optimize the structure and parameters of the punchthrough enhanced phototransistor. We change the structure from traditional form, which is the combination of a NB (Narrow Base) punchthrough transistor and a WB (Wide Base) phototransistor to just one side, to a new shape of the narrow base punchthrough transistor sandwiched in two wide base phototransistors which are both half of the old length. We investigate the electrical properties and optical conversion performance of the device such as dark current, photocurrent and optical sensitivity versus bias voltage with different width of the narrow base region. The optimized width of the narrow base is obtained after we analyze the simulated result. The analysis of the photocurrent and optical sensitivity versus bias voltage with different light power are presented to reveal the character of different light power. When the width of the narrow base is 0.6 μm, the performance of the device is a optimum compromise. The dark current is only 1 μA when the bias voltage is 0.5 V. The optical sensitivity is 4×10⁶ A/W when the light power is 10^-7 W/cm².