共查询到13条相似文献,搜索用时 15 毫秒
1.
2.
采用在发射区台面腐蚀时保留InGaP钝化层和去除InGaP钝化层的方法制备了两种InGaP/GaAs异质结双极晶体管(HBT)器件,研究了InGaP钝化层对HBT器件基区表面电流复合以及器件直流和射频微波特性的影响.对制备的两种器件进行了对比测试后得到:保留InGaP钝化层的HBT器件最大直流增益(β)为130,最高振荡频率(fmax)大于53 GHz,功率附加效率达到61%,线性功率增益为23 dB;而去除InGaP钝化层的器件最大β为50,fnax大于43 GHz,功率附加效率为57%,线性功率增益为18 dB.测试结果表明,InGaP钝化层作为一种耗尽型的钝化层能有效抑制基区表面电流的复合,提高器件直流增益,改善器件的射频微波特性. 相似文献
3.
一种简化的VBIC模型和InGaP/GaAs HBT宽带放大器设计 总被引:2,自引:2,他引:0
采用一种新的简化VBIC模型对单、多指InGaP/GaAs HBT器件进行建模.测量和模型仿真I-V特性及其在多偏置条件下多频率点S参数对比结果表明,DC~9GHz频率范围内,简化后的模型可对InGaP/GaAs HBT交流小信号特性进行较好的表征.利用建立的模型设计出DC~9GHz两级直接耦合宽带放大器,该放大器增益达到19dB,输入、输出回波损耗分别低于-10dB和-8dB. 相似文献
4.
Optimization of emitter cap growth conditions for InGaP/GaAs HBTs with high current gain by LP-MOCVD
The effect of emitter cap growth conditions on the common-emitter current gain of InGaP/GaAs HBTs, grown by LP-MOCVD, has
been studied. This work shows that the material quality of a carbon-doped base is highly dependent on the emitter cap growth.
The emitter cap growth effectively serves as a source of thermal stress. This stress on the base during the emitter and cap
growth causes the formation of carbon-related defects in the base that increase the base recombination and reduces the current
gain. Atomic force microscopy is used to identify these carbon-related defects. Gain improvements of about 40% have been achieved
by optimizing the emitter cap growth conditions to reduce the thermal stress. 相似文献
5.
A self-aligned InGaP/GaAs HBT DC and RF characteristics related with orientations were studied. The DC current gain was greater for the [0 1 1] emitter orientation compared to orientation. However, it also showed slightly better RF performance for orientation with a cutoff frequency fT 69 GHz compared to the fT of 62 GHz for the [0 1 1] orientation. This experimental work has been proposed that the dependence of the characteristics could be attributed to both piezoelectric effect and the difference between lateral etched profiles in different directions. 相似文献
6.
研究了不同基区设计对多发射极指结构功率InGaP/GaAs异质结双极型晶体管热稳定性的影响。以发生电流增益崩塌的临界功率密度为热稳定性判定标准,推导了热电反馈系数Φ、集电极电流理想因子η和热阻Rth与基区掺杂浓度NB、基区厚度dB的理论公式。基于TCAD虚拟实验,观测了不同基区掺杂浓度和不同基区厚度分别对InGaP/GaAs HBT热稳定性的影响。结合理论公式,对仿真实验曲线进行了分析。结果表明,基区设计参数对热稳定性有明显的影响,其影响规律不是单调变化的。通过基区外延层参数的优化设计,可以改进多指HBT器件的热稳定性,从而为多指InGaP/GaAs HBT热稳定性设计提供了一个新的途径。 相似文献
7.
为全面评估航天型号用元器件的抗辐射性能,对InGaP/GaAs异质结双极晶体管(Heterojunction Bipolar Transistor,HBT)的单粒子效应进行了仿真研究。首先,介绍了空间辐射环境中重离子诱发器件产生单粒子瞬态脉冲的机理。然后,建立了InGaP/GaAs HBT器件三维仿真模型,并利用蒙特卡罗方法模拟了不同能量的C、F、Cl、Br、I等重离子在器件中的射程和LET值。最后,基于ISE-TCAD仿真软件对器件的单粒子瞬态脉冲电流曲线进行了仿真和分析。结果表明:重离子在器件中产生的集电极瞬态脉冲电流可达几百微安,集电极瞬态脉冲电流与重离子的能量成反比,与离子的原子序数成正比。由此可知,InGaP/GaAs HBT器件对单粒子效应比较敏感,且对不同重离子的敏感程度不同。这可以为航天型号用元器件的设计选型和可靠性评估提供技术支撑。 相似文献
8.
K. A. Jones R. T. Lareau T. Monahan J. R. Flemish R. L. Pfeffer R. E. Sherriff C. W. Litton R. L. Jones C. E. Stutz D. C. Look 《Journal of Electronic Materials》1995,24(11):1641-1648
Symmetric δ-doped InGaP and AlGaAs PHEMT structures have been grown by organometallic vapor phase epitaxy with properties
that approach those of MBE grown AlGaAs structures. The 300 and 77K carrier concentrations for the InGaP PHEMT were 2.72 and
2.56 × 1012 cm2
−2 and the mobilities were 5,920 and 22,000 cm2
2/V.s. These excellent values suggest that problems associated with switching the anion at the channel heterojunction have
been overcome. The corresponding values for the AlGaAs PHEMT were 2.51 and 2.19 × 1012 cm2
−2 and 6,500 and 20,400 cm2/V.s. The uniformity in the indium concentration in the InGaAs layer as determined by photoluminescence, photoreflection,
double crystal x-ray diffraction, and Rutherford backscattering was found to be good, but the percent In in the AlGaAs pseudo-morphic
high electron mobility transistor (PHEMT) was less than that in the InGaP PHEMT even though the programmed values were the
same. The uniformity in the doping distribution as determined by secondary ion mass spectroscopy and electrochemical capacitance-voltage
measurements was found to be good, but it decreased with distance from the center of the susceptor. Also, most of the dopants
in the δ-doped InGaP and AlGaAs layers were activated. 相似文献
9.
10.
A 6 GHz voltage controlled oscillator (VCO) optimized for power and noise performance was designed and characterized. This VCO was designed with the negative-resistance (Neg-R) method, utilizing an InGaP/GaAs hetero-junction bipolar transistor in the negative-resistance block. A proper output matching network and a high Q stripe line resonator were used to enhance output power and depress phase noise. Measured central frequency of the VCO was 6.008 GHz. The tuning range was more than 200 MHz. At the central frequency, an output power of 9.8 dBm and phase noise of -122.33 dBc/Hz at 1 MHz offset were achieved, the calculated RF to DC efficiency was about 14%, and the figure of merit was -179.2 dBc/Hz. 相似文献
11.
A 6 GHz voltage controlled oscillator (VCO) optimized for power and noise performance was designed and characterized. This VCO was designed with the negative-resistance (Neg-R) method, utilizing an InGaP/GaAs hetero-junction bipolar transistor in the negative-resistance block. A proper output matching network and a high Q stripe line resonator were used to enhance output power and depress phase noise. Measured central frequency of the VCO was 6.008 GHz. The tuning range was more than 200 MHz. At the central frequency, an output power of 9.8 dBm and phase noise of-122.33 dBc/Hz at 1 MHz offset were achieved, the calculated RF to DC efficiency was about 14%, and the figure of merit was -179.2 dBc/Hz. 相似文献
12.
Au/Pd/p-GaAs Schottky diodes were fabricated by simple assembly of monodisperse Pd nanoparticles on a p-type GaAs semiconductor. Monodisperse 5-nm Pd nanoparticles were synthesized via reduction of palladium(II) acetylacetonate in oleylamine using a borane tert-butylamine complex. The Au/Pd/p-GaAs Schottky diodes provided a barrier height of 0.68 eV, which is higher than room-temperature values reported in the literature. A double distribution was observed for the barrier height for the Schottky diodes from I–V–T measurements. A decrease in temperature lowered the zero-bias barrier height and increased the ideality factor. These observations were ascribed to barrier height inhomogeneities at the interface that altered the barrier height distribution. Values of the series resistance obtained by the Norde method decreased with increasing temperature. Understanding the temperature dependence of the current–voltage characteristics of Au/Pd/p-GaAs devices might be helpful in improving the quality of Pd deposited on GaAs for future device technologies. 相似文献
13.
Gold-based ohmic contacts, incorporating Pt, Pd, and Zn layers, to AIGaAs/GaAs heterojunction bipolar transistors (HBTs) have
been characterized using transmission electron microscopy (TEM). The metallization was deposited onto a 30 nm graded emitter
layer of n-type AlxGa1−xAs, which was on a 30 nm emitter layer of n-type Al0.3Ga0.7As, with the aim of contacting the underlying 80 nm thick graded base layer of p-type AlxGa1−xAs. Metal layers were deposited sequentially using electron beam evaporation and the resultant metallizations were annealed
at temperatures ranging from 250-500°C for up to several minutes. A minimum contact resistance of ≈8.5 × 10−7 Ω-cm2 was achieved, which corresponded to the decomposition of ternary phases at the metallization/semiconductor interface, to
binary phases, i.e., PdGa and PtAs2. Long term stability tests were done on the optimum contacts. Anneals at 270°C for up to four weeks in duration produced
virtually no change in microstructure, with the exception of some outward diffusion of Ga and As. 相似文献