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NPN型晶体管辐射损伤及退火效应研究

Research on Radiation and Annealing Effects of NPN Transistors

【作者】 赵志明

【导师】 耿洪滨;

【作者基本信息】 哈尔滨工业大学 , 材料学, 2010, 硕士

【摘要】 本文采用低能质子和电子作为辐照源,研究了NPN双极型晶体管(3DG112D)在辐照过程中的性能退化规律。电流增益是双极型晶体管的电性能参数中关键的参数,其衰减是双极型晶体管最显著同时也是最典型的辐射损伤效应。本文中除研究双极型晶体管电流增益随辐照注量的变化外,还在辐照试验完成后,研究了电流增益随退火时间、温度、偏置条件的变化规律。研究表明,在相同的辐照源种类、粒子能量及通量条件下,NPN型晶体管电性能参数随着辐照注量的不断增加而加剧;当晶体管受到110和70keV电子辐照,70keV质子辐照时,其电流增益的倒数随辐照注量的增加而增加且逐渐趋于饱和状态;当晶体管受到170keV质子辐照时其电流增益的倒数随辐照注量的增加而增加且呈线性关系;当170keV与110keV电子同时辐照时,位移损伤效应起了主导作用,而电离效应会对加剧位移损伤的影响。退火试验结果表明,等温退火时,NPN型晶体管电性能随退火时间的增加逐渐恢复。等时退火时,温度越高,NPN型晶体管电性能的退火效应越明显。在退火过程中,发射结反偏,会加速NPN型晶体管的电性能恢复;而发射结正偏的影响较小。不同种类辐照源对退火效应的影响也不相同。低能电子对NPN型晶体管造成的电离损伤在较低温度(低于300℃)就能完全恢复,而由低能质子造成损伤则需要较高的温度(500℃)才能有明显的恢复效果。

【Abstract】 The degradation caused by low energy protons and electrons are examined for the NPN transistors (3DG112D). The current gain is one of the most important parameters of bipolar junction transistors (BJTs). The degradation of the current gain for transistor is significant and typical radiation damage effect. The electrical parameters of NPN transistors are measured during the irradiation. After irradiation, the changes in current gain with annealing time, temperature and bias are investigated.The results show that, with increasing the irradiation fluence, the trends of degradation in electrical parameters of NPN transistors are similar, under the irradiation of different particles, fluxes and energies. When the NPN transistors are irradiated by 110keV, 70keV electrons and 70keV protons, the reciprocal of the current gain of NPN transistors increases and is gradually saturated with increasing the fluence. When the NPN transistors are irradiated by 170keV, the reciprocal of the current gain of NPN transistors increases linearly with the irradiation fluence. The damage irradiated by both 110keVelectrons and 170keV protons at the same time is more serious than that by just one kind of irradiation sources.Based on the annealing effects research, the current gain of the NPN transistor is gradually recovered with time during isothermal annealing, while the higher the temperature, the larger the annealing velocities during isochronous annealing. Moreover, the annealing will be accelerated, if the emitter is negative biased. However, there will be little influence if the emitter is positive biased. On the other hand, the annealing effect is also affected by the irradiation sources. The ionization damage caused by low energy electrons could disappear with relatively low annealing temperature (300℃). The damage induced by low energy protons will not be removed entirely even with rather high the temperature (500℃).

  • 【分类号】TN32
  • 【被引频次】2
  • 【下载频次】122
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