共查询到19条相似文献,搜索用时 78 毫秒
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提出了发射极非均匀指间距技术以增强多发射极指SiGe HBT在不同环境温度下的热稳定性。通过建立热电反馈模型对采用发射极非均匀指间距技术的SiGe HBT进行热稳定性分析,得到多发射极指上的温度分布。结果表明,与传统的均匀发射极指间距SiGe HBT相比,在相同的环境温度及耗散功率下,采用发射极非均匀指间距技术的SiGe HBT,其最高结温明显降低,热阻显著减小,温度分布更加均匀,有效地提高了多发射极指功率SiGe HBT在不同环境温度下的热稳定性。 相似文献
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为了改善高压功率SiGe HBT的综合性能,应用图形外延SiGe工艺,研制出了一种新型的双多晶自对准SiGe HBT器件.相对于双台面结构的SiGe HBT而言,该结构的SiGe HBT在发射极总周长不变的情况下,其发射结面积减少超过50%,集电结面积减少近70%,BVCBO也提高了近28%.经测试,器件的结漏电和直流增益等参数均符合设计要求. 相似文献
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Jinshu Zhang Hongyong Jia Pei-Hsin Tsien Tai-Chin Lo 《Electron Device Letters, IEEE》1999,20(7):326-328
The emitter ballasting resistor is used to equalize the current distribution between the emitter stripes in power transistor, but it will degrade the output power, power gain, and power added efficiency. Experimental results indicate that the current gain of uniform-base SiGe heterojunction bipolar transistors (HBTs) decreases with the increase of the temperature above 160 K, so the current distribution is equalized by itself to some extent. Therefore, the microwave power SiGe HBTs without emitter ballasting resistor were fabricated for the first time, and the continuous output power of 5 W and power added efficiency of 63% were obtained under Class C operation at a frequency of 900 MHz. Hence, the emitter current density of the SiGe HBT's with emitter width of 6 μm is 0.79 A/cm 相似文献
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Babcock J.A. Cressler J.D. Vempati L.S. Clark S.D. Jaeger R.C. Harame D.L. 《Electron Device Letters, IEEE》1995,16(8):351-353
The effect of ionizing radiation on both the electrical and 1/f noise characteristics of advanced UHV/CVD SiGe HBT's is reported for the first time. Only minor degradation in the current-voltage characteristics of both SiGe HBT's and Si BJT's is observed after total radiation dose exposure of 2.0 Mrad(Si) of gamma-radiation. The observed immunity to ionizing radiation exposure suggests that these SiGe HBT's are well suited for many applications requiring radiation tolerance. We have also observed the appearance of ionizing-radiation-induced generation-recombination (G/R) noise in some of these SiGe HBT's 相似文献
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Joseph A.J. Cressler J.D. Richey D.M. Jaeger R.C. Harame D.L. 《Electron Devices, IEEE Transactions on》1997,44(3):404-413
We present the first comprehensive investigation of neutral base recombination (NBR) in ultra-high vacuum/chemical vapor deposited (UHV/CVD) SiGe heterojunction bipolar transistors (HBT's), and its influence on the temperature characteristics of Early voltage (VA ) and current gain-Early voltage product (βVA). We show that a direct consequence of NBR in SiGe HBT's is the degradation of VA when transistors are operated with constant-current input (forced-IB) as opposed to a constant-voltage input (forced-VBE). In addition, experimental and theoretical evidence indicates that with cooling, VA in SiGe HBT's degrades faster than in Si bipolar junction transistors (BJT's) for forced-IB mode of operation. Under the forced-VBE mode of operation, however, SiGe HBT's exhibit a thermally-activated behavior for both VA and βVA, in agreement with the first-order theory. The differences in VA as a function of the input bias and temperature for SiGe HBT's are accurately modeled using a modified version of SPICE. The performance of various practical SiGe HBT circuits as a function of temperature, in the presence of NBR, is analyzed using this calibrated SPICE model 相似文献
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提出了一个模拟SiGe基区HBT器件特性的物理模型。在基区部分考虑了发射结处的价带不连续、大注入效应、Ge组份变化及重掺杂效应引起的能带变化的影响;在集电区分析时考虑了基区推出效应、载流子速度饱和效应、电流引起的空间电荷区效应以及准饱和效应。在此基础上给出了SiGe基区HBT器件的电流和电荷公式。同时开发了SiGe基区HBT的直流瞬态模型和小信号模型。利用修改的SPICE程序模拟了实际SiGe基区 相似文献
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Hot electron and hot hole degradation of UHV/CVD SiGe HBT's 总被引:1,自引:0,他引:1
Gogineni U. Cressler J.D. Niu G. Harame D.L. 《Electron Devices, IEEE Transactions on》2000,47(7):1440-1448
We investigate the degradation in current gain and low-frequency noise of SiGe HBT's under reverse emitter-base stress due to hot electrons (forward-collector stress) and hot holes (open-collector stress). Contrary to previous assumptions we show that hot electrons and hot holes with the same kinetic energy generate different amounts of traps and hence have a different impact on device degradation. These results suggest that the accuracy of using forward-collector stress as an acceleration tool and reliability predictor must be carefully examined. We also present, for the first time, the effect of Ge profile shape on the reliability of SiGe HBT's, as well as discuss measurements on SiGe HBT's as a function of device geometry and temperature 相似文献