Investigation of Current Gain Degradation in 4H-SiC Power BJTs

2012 ◽  
Vol 717-720 ◽  
pp. 1131-1134 ◽  
Author(s):  
Benedetto Buono ◽  
Reza Ghandi ◽  
Martin Domeij ◽  
Bengt Gunnar Malm ◽  
Carl Mikael Zetterling ◽  
...  
Keyword(s):  
Behavior Analysis ◽  
Carrier Lifetime ◽  
Passivation Layer ◽  
Current Gain ◽  
Degradation Behavior ◽  
Device Design ◽  
Base Region ◽  
Base Current ◽  
Electrical Stress

The current gain degradation of 4H-SiC BJTs with no significant drift of the on-resistance is investigated. Electrical stress on devices with different emitter widths suggests that the device design can influence the degradation behavior. Analysis of the base current extrapolated from the Gummel plot indicates that the reduction of the carrier lifetime in the base region could be the cause for the degradation of the gain. However, analysis of the base current of the base-emitter diode shows that the degradation of the passivation layer could also influence the reduction of the current gain.

scholarly journals Total Dose Effects on 4H-SiC Bipolar Junction Transistors

2017 ◽  
Vol 897 ◽  
pp. 579-582
Author(s):  
Sethu Saveda Suvanam ◽  
Luigia Lanni ◽  
Bengt Gunnar Malm ◽  
Carl Mikael Zetterling ◽  
Anders Hallén
Keyword(s):  
Total Dose ◽  
Detailed Analysis ◽  
Surface Recombination ◽  
Current Gain ◽  
Bipolar Junction Transistors ◽  
Displacement Damage ◽  
Base Current ◽  
Dose Effects ◽  
Order Of Magnitude ◽  
Total Dose Effects

In this work, total dose effects on 4H-SiC bipolar junction transistors (BJT) are investigated. Three 4H-SiC NPN BJT chips are irradiated with 3MeV protons with a dose of 1×1011, 1×1012 and 1×1013 cm-2, respectively. From the measured reciprocal current gain it is observed that 4H-SiC NPN BJT exposed to protons suffer both displacement damage and ionization, whereas, a traditional Si BJT suffers mainly from displacement damage. Furthermore, bulk damage introduction rates for SiC BJT were extracted to be 3.3×10-15 cm2, which is an order of magnitude lower compared to reported Si values. Finally, from detailed analysis of the base current at low injection levels, it is possible to distinguish when surface recombination leakage is dominant over bulk recombination.

Impact of Carrier Lifetime Enhancement Using High Temperature Oxidation on 15 kV 4H-SiC P-GTO Thyristor

2017 ◽  
Vol 897 ◽  
pp. 587-590 ◽  
Author(s):  
Sei Hyung Ryu ◽  
Daniel J. Lichtenwalner ◽  
Edward van Brunt ◽  
Craig Capell ◽  
Michael J. O’Loughlin ◽  
...  
Keyword(s):  
High Temperature ◽  
Carrier Lifetime ◽  
Voltage Drop ◽  
Current Gain ◽  
Slight Reduction ◽  
Temperature Oxidation ◽  
Forward Voltage Drop ◽  
P Type ◽  
The Impact ◽  
Lifetime Enhancement

The impact of the lifetime enhancement process using high temperature thermal oxidation method on 4H-SiC P-GTOs was investigated. 15 kV 4H-SiC P-GTOs with 140 μm thick drift layers, with and without 1450°C lifetime enhancement oxidation (LEO) process, were compared. The LEO process increased the average carrier lifetime in p-type epi layer from 0.9 μs to 6.25 μs, and it was observed that the effectiveness of the lifetime enhancement process was very sensitive to the doping concentration. The device with the LEO process showed a significant reduction in forward voltage drop and a substantially lower holding current, as expected from the carrier lifetime measurements. However, a slight reduction in blocking capability was also observed from the devices treated with LEO process. The common emitter current gain (β) of the wide base test NPN BJT was approximately 10X higher for the wafer with LEO process.

GAIN DEGRADATION AND ENHANCED LOW-DOSE-RATE SENSITIVITY IN BIPOLAR JUNCTION TRANSISTORS

2004 ◽  
Vol 14 (02) ◽  
pp. 503-517 ◽  
Author(s):  
R. D. SCHRIMPF
Keyword(s):  
Dose Rate ◽  
Low Dose ◽  
Surface Recombination ◽  
Rate Sensitivity ◽  
Current Gain ◽  
Bipolar Junction Transistors ◽  
Base Current ◽  
Low Dose Rate ◽  
Two Factors ◽  
Recombination Current

The current gain of irradiated bipolar junction transistors decreases due to increased recombination current in the emitter-base depletion region and the neutral base. This recombination current depends on the interaction of two factors: (1) decreased minority-carrier lifetime at the Si / SiO 2 interface or in the bulk Si and (2) changes in surface potential caused by charge in the oxide. In npn transistors, these two factors both result in increased base current, while in pnp devices, positive charge in the oxide moderates the increase in base current due to surface recombination. In some technologies, the amount of degradation that occurs at a given total dose increases as the dose rate decreases. This enhanced low-dose-rate sensitivity results from space-charge effects produced by slowly transporting holes and protons in the oxide that covers the emitterbase junction.

Backscattering and common-base current gain of the Graphene Base Transistor (GBT)

2015 ◽  
Vol 147 ◽  
pp. 192-195 ◽  
Author(s):  
Stefano Venica ◽  
Francesco Driussi ◽  
Pierpaolo Palestri ◽  
Luca Selmi
Keyword(s):  
Current Gain ◽  
Base Current ◽  
Common Base

Effects of Electrical Stress and High-Energy Electron Irradiation on the InGaP/GaAs Heterojunction Phototransistor

2015 ◽  
Vol 1792 ◽  
Author(s):  
Phuc Hong Than ◽  
Kazuo Uchida ◽  
Takahiro Makino ◽  
Takeshi Ohshima ◽  
Shinji Nozaki
Keyword(s):  
Electron Irradiation ◽  
Room Temperature ◽  
High Energy ◽  
Energy Electron ◽  
Current Gain ◽  
Related Phenomenon ◽  
High Energy Electron ◽  
Collector Current ◽  
Emitter Current ◽  
Electrical Stress

ABSTRACTIn this paper, we discuss the characteristics of the InGaP/GaAs heterojunction phototransistors (HPTs) before and after the electrical stress at room temperature and assess the effectiveness of the emitter-ledge passivation. Although an electrical stress given to the phototransistors by keeping a collector current density of 37 A/cm2 for 1 hour at room temperature was too small to affect the room-temperature common-emitter current gain and photocurrent of both HPTs with and without the emitter-ledge passivation, they showed a significant decrease at 420 K due to the room-temperature electrical stress. Nevertheless, the room-temperature common-emitter current gain and photocurrent of the HPT with the emitter-ledge passivation were still higher than those of the HPT without the emitter-ledge passivation. The effectiveness of the emitter-ledge passivation against the electrical stress was more significant than that on the current gain in the dark. In addition to the electrical stress experiment, for a potential application of the InGaP/GaAs HPTs in space, we will irradiate the HPTs with 1-MeV electrons at the Japan Atomic Energy Agency. Both current gain and photocurrent decreased significantly after the electron irradiation. In contrast to the electrical stress, the damage due to the high-energy electron irradiation is a bulk-related phenomenon, and the emitter-ledge passivation does not seem to suppress the degradation.

Improved Current Gain in 4H-SiC BJTs Passivated with Deposited Oxides Followed by Nitridation

2011 ◽  
Vol 679-680 ◽  
pp. 698-701
Author(s):  
Hiroki Miyake ◽  
Tsunenobu Kimoto ◽  
Jun Suda
Keyword(s):  
Surface Passivation ◽  
Passivation Layer ◽  
Current Gain ◽  
Bipolar Junction Transistors ◽  
High Current ◽  
Post Deposition Annealing ◽  
Thermally Grown Oxides ◽  
Post Deposition ◽  
Thermally Grown

We report the improvement of current gain in 4H-SiC bipolar junction transistors (BJTs) by using deposited oxides as a surface passivation layer. Various post-deposition annealing processes were investigated. We successfully demonstrated SiC BJTs with a high current gain (β) of 86 using deposited oxides annealed in NO. This is 70% higher current gain compared with that of BJTs with the same structure with conventional thermally-grown oxides.

scholarly journals Effects of Chamber Pressures on the Passivation Layer of Hydrogenated Nano-Crystalline Silicon Mixed-Phase Thin Film by Using Microwave Annealing

Electronics ◽  
2021 ◽  
Vol 10 (18) ◽  
pp. 2199
Author(s):  
Jia-Hao Lin ◽  
Hung-Wei Wu ◽  
Wei-Chen Tien ◽  
Cheng-Yuan Hung ◽  
Shih-Kun Liu
Keyword(s):  
Thin Film ◽  
Carrier Lifetime ◽  
Volume Fraction ◽  
Crystalline Silicon ◽  
Mixed Phase ◽  
Passivation Layer ◽  
Very High Frequency ◽  
Microwave Annealing ◽  
Symmetric Structure ◽  
Nano Crystalline

This paper proposes the effects of chamber pressures on the passivation layer of hydrogenated nano-crystalline silicon (nc-Si:H) mixed-phase thin film using microwave annealing (MWA) to achieve a high-quality thin film. The use of 40.68 MHz very-high-frequency plasma-enhanced chemical vapor deposition (VHFPECVD) deposited the nc-Si:H mixed-phase thin film on the top and bottom of the n-type crystalline silicon substrate. The chamber pressures (0.2, 0.4, 0.6, and 0.8 Torr) of the VHFPECVD were critical factors in controlling the carrier lifetime of the symmetric structure. By using the VHFPECVD to deposit the nc-Si:H and using the MWA to enhance the quality of the symmetric structure, the deposited nc-Si:H’s properties of a crystalline volume fraction of 29.6%, an optical bandgap of 1.744 eV, and a carrier lifetime of 2942.36 μs were well achieved, and could be valuable in thin-film solar-cell applications.

Sign in / Sign up

Export Citation Format

Share Document