scholarly journals Investigation of Base Transport Mechanism in Silicon-Germanium Heterojunction Bipolar Transistor Operating over Wide Temperature Range

2021 ◽  
Vol 2065 (1) ◽  
pp. 012013
Author(s):  
Guofang Yu ◽  
Jie Cui ◽  
Yue Zhao ◽  
Jun Fu ◽  
Tian-Ling Ren
Keyword(s):  
Wide Temperature Range ◽  
Silicon Germanium ◽  
Transport Mechanism ◽  
Bipolar Transistor ◽  
Heterojunction Bipolar Transistor ◽  
Collector Current ◽  
Base Current ◽  
Temperature Range ◽  
Trap Assisted Tunneling ◽  
Assisted Tunneling

Abstract A high breakdown voltage silicon-germanium heterojunction bipolar transistor operated over a wide temperature range from 300 K to 10 K has been investigated. The measured Gummel characteristics illustrate that the collector current and base current both shift to the higher voltage as the temperature decreases. The fT/fmax are extracted to be 23/40 GHz at 300K, 28/40 GHz at 90 K, and 25/37GHz at 10K, respectively. The effective amplification range becomes narrow as the temperature decreases. And the ideality factor of base current in the low current region is shown to be temperature-dependent and its value is much larger than 2 at cryogenic temperatures. This phenomenon indicates that the base current is not only contributed by drift, diffusion, and Shockley-Read-Hall recombination, but also by trap-assisted tunneling. The Hurkx local trap-assisted tunneling has been used to analyze the non-ideal base transport mechanism. And a calibrated TCAD device model is developed to further verify this non-ideal transport mechanism.

Elevated Temperature Characteristics of Carbon-Doped GaInP/GaAs Heterojunction Bipolar Transistor Grown by Solid Source Molecular Beam Epitaxy

2003 ◽  
Vol 799 ◽  
Author(s):  
Zhang Rong ◽  
Yoon Soon Fatt ◽  
Tan Kianhua ◽  
Sun Zhongzhe ◽  
Huang Qingfeng
Keyword(s):  
Activation Energy ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Base Material ◽  
Bipolar Transistor ◽  
Heterojunction Bipolar Transistor ◽  
Collector Current ◽  
Carbon Doped ◽  
Base Current ◽  
Recombination Current

ABSTRACTThis paper reports the characteristics of GaInP/GaAs heterojunction bipolar transistor (HBT) with carbon-doped GaAs base layer grown by solid source molecular beam epitaxy (SSMBE) using carbon tetrabromide (CBr4) as p-type dopant precursor. Hydrofluoric acid (HF) was used to passivate the GaInP/GaAs HBTs. At base bias voltages below 0.8V in the Gummel plot, the base current of large-area devices after HF treatment was greatly reduced. This indicates that the extrinsic base surface recombination current was greatly reduced. After HF treatment, detailed DC characterization of the device performance from 300K to 380K was carried out and the carrier transport properties were investigated. The base current and collector current ideality factors at 300K were 1.12 and 1.01, respectively. This indicates that the space- charge region recombination current in the base is insignificant. From the temperature- dependent Gummel plot, the activation energies of collector current and base current were obtained. For the collector current, the activation energy is 1.4eV, which is close to the bandgap of the GaAs base. This indicates that the collector current is determined by the drift-diffusion process, in which an energy barrier of the same magnitude as the base bandgap is to be overcome by electrons before they reach the collector. For the base current, the activation energy is also 1.4eV, which is close to the bandgap of GaAs, indicating that band-to-band recombination plays a dominant role in the base current. No trap-related recombination was observed for the base and collector currents, which further indicates the high quality carbon-doped GaAs base material for the HBT structures.

Study of electromagnetic field stress impact on SiGe heterojunction bipolar transistor performance

2009 ◽  
Vol 1 (6) ◽  
pp. 475-482 ◽  
Author(s):  
Ali Alaeddine ◽  
Moncef Kadi ◽  
Kaouther Daoud ◽  
Hichame Maanane ◽  
Philippe Eudeline
Keyword(s):  
Electromagnetic Field ◽  
Near Field ◽  
Bipolar Transistor ◽  
Heterojunction Bipolar Transistor ◽  
Scattering Parameters ◽  
Hot Carrier ◽  
Base Current ◽  
Stress Effects ◽  
Device Reliability ◽  
Strip Lines

This paper deals with the various aspects of electromagnetic field impact modeling on the SiGe heterojunction bipolar transistor (HBT) device for microwave applications. This study differs from conventional HBT device reliability research associated with other stresses. The originality of this study comes from the generation of a localized electromagnetic field using the near-field bench. A coupling phenomenon between the electromagnetic field and the micro-strip lines connecting the transistor are evaluated by electromagnetic and electrical simulations. After stress, the input and the transmission scattering parameters are affected. This is primarily due to the deviation of the input impedance and the reduction of the transconductance, respectively. The stress effects have been related to a base current degradation. This degradation is due to a hot carrier introducing generation/recombination trap centers at the Si/SiO2 interface of the emitter–base spacer oxide, which leads to an excess recombination base current.

Current Gain of an AlGaN/GaN Heterojunction Bipolar Transistor

2001 ◽  
Vol 680 ◽  
Author(s):  
Yumin Zhang ◽  
P. Paul Ruden
Keyword(s):  
Electron Transport ◽  
Hybrid Model ◽  
Carrier Transport ◽  
Effective Field ◽  
Structure Design ◽  
Bipolar Transistor ◽  
Heterojunction Bipolar Transistor ◽  
Current Gain ◽  
Design Parameters ◽  
Collector Current

ABSTRACTA novel hybrid model and simulation results for an advanced, graded base AlGaN/GaN heterojunction bipolar transistor structure are presented. The base of the n-p-n HBT examined has two parts, a linearly graded AlGaN layer on the emitter side and a heavily p-doped GaN layer on the collector side. In the hybrid model developed here the potential profile is first calculated self-consistently in the biased state taking into account ionized impurity charges, polarization charges, and majority carrier charges. The minority carrier transport is examined subsequently. Injection of electrons from the emitter is modeled as a thermionic emission process. The minority electron transport process in the graded region is drift-dominated due to the large built-in effective field strength. In the low-field GaN layer of the base, electron transport is assumed to be diffusion-dominated. High-level injection effects are modeled in the framework of the Gummel-Poon model. Example structure design parameters are presented and it is found that the calculated current gain can be greater than 25, with a collector current density of 104A/cm2.

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