发射极尺寸对双多晶自对准双极晶体管剂量率效应的影响

Dependence of emitter size on dose rate effect of double polysilicon self-aligned bipolar transistors

为了研究发射极尺寸对双多晶自对准NPN型双极晶体管电离辐射剂量率效应的影响,对不同发射极尺寸双多晶自对准NPN双极晶体管在高低剂量率辐照条件下进行了辐照实验,在实验数据基础上对其损伤特性以及损伤机理进行的分析表明,高低剂量率辐照下双多晶自对准工艺制备的NPN型双极晶体管都具有良好的抗电离辐照损伤能力,且低剂量率辐照损伤均大于高剂量率。同时,实验及理论分析结果都表明:双多晶自对准双极晶体管的抗辐照能力与发射极的周长面积比密切相关,发射极周长面积比越小,晶体管抗辐照能力越强,且在发射极宽度一定时,发射极条越长抗辐照能力越强。

[Background] As the state-of-the-art high speed bipolar complementary process, the high performance and speed analog integrated circuit making by double-polysilicon self-aligned （DPSA） technology has a wide application prospect in the extreme fields of space radio frequency （RF）/microwave communication. [Purpose] This study aims to investigate the response of high- and low-dose-rate irradiation on domestic double polysilicon self-aligned NPN transistors with different emitter sizes, analyze the dependence of emitter size on dose rate effect of DPSA NPN bipolar junction transistor （BJT）. [Methods] The two different emitter size devices were irradiated to a maximum total ionizing dose level of 1 000 Gy（Si） under the high （0.5 Gy（Si）.s^-l） and low （lx10^-4 Gy（Si）·s^-1） dose rate. The electrical parameters including Gummel characteristics and direct current gain of the devices were measured with Keithley 4200-SCS semiconductor parameter analyzer removed from the irradiation room within 20 rain at room temperature before and after each specified value of accumulated dose. [Results] The NPN DPSA bipolar transistors have good resistance to ionizing radiation damage under high and low dose rate irradiation, and the low dose rate irradiation damage is greater than the high dose rate. Meanwhile, the smaller the perimeter area ratio of the emitter, the smaller the transistor degradation. [Conclusions] The DPSA NPN BJT has a great tolerance of the ionizing radiation for the application of the extreme radiation environment, and the smaller perimeter area ratio it has, the better the performance of the tolerance.