SiC MOSFET Channel Mobility Dependence on Substrate Doping and Temperature Considering High Density of Interface Traps

2007 ◽  
pp. 835-838
Author(s):  
A. Pérez-Tomás ◽  
M.R. Jennings ◽  
P.A. Mawby ◽  
J.A. Covington ◽  
Phillippe Godignon ◽  
...  
Keyword(s):  
High Density ◽  
Interface Traps ◽  
Channel Mobility ◽  
Substrate Doping

SiC MOSFET Channel Mobility Dependence on Substrate Doping and Temperature Considering High Density of Interface Traps

2007 ◽  
Vol 556-557 ◽  
pp. 835-838 ◽  
Author(s):  
Amador Pérez-Tomás ◽  
Michael R. Jennings ◽  
Philip A. Mawby ◽  
James A. Covington ◽  
Phillippe Godignon ◽  
...  
Keyword(s):  
Degradation Mechanism ◽  
Mobility Model ◽  
Effect Of Temperature ◽  
Coulomb Scattering ◽  
Interface Traps ◽  
Channel Mobility ◽  
Inversion Channel ◽  
Scattering Effects ◽  
Charge Concentration ◽  
Substrate Doping

In prior work we have proposed a mobility model for describing the mobility degradation observed in SiC MOSFET devices, suitable for being implemented into a commercial simulator, including Coulomb scattering effects at interface traps. In this paper, the effect of temperature and doping on the channel mobility has been modelled. The computation results suggest that the Coulomb scattering at charged interface traps is the dominant degradation mechanism. Simulations also show that a temperature increase implies an improvement in field-effect mobility since the inversion channel concentration increases and the trapped charge is reduced due to bandgap narrowing. In contrast, increasing the substrate impurity concentration further degrades the fieldeffect mobility since the inversion charge concentration decreases for a given gate bias. We have good agreement between the computational results and experimental mobility measurements.

Gamma Irradiation Effects on 4H-SiC MOS Capacitors and MOSFETs

2006 ◽  
Vol 527-529 ◽  
pp. 1063-1066 ◽  
Author(s):  
Ayayi Claude Ahyi ◽  
S.R. Wang ◽  
John R. Williams
Keyword(s):  
Field Effect ◽  
Gamma Dose ◽  
Interface Traps ◽  
Valence Band Edge ◽  
Field Effect Mobility ◽  
Irradiation Effects ◽  
Mos Capacitors ◽  
Channel Mobility ◽  
Radiation Induced ◽  
Radiation Tolerant

The effects of gamma radiation on field effect mobility and threshold voltage have been studied for lateral n-channel 4H-SiC MOSFETs passivated with nitric oxide. MOS capacitors (n and p) and n-channel lateral MOSFETs were irradiated unbiased (floating contacts) for a total gamma dose of 6.8Mrad (Si). The MOS capacitors were used to study the radiation-induced interface traps and fixed oxide charge that affect the performance of the MOSFETs. Radiationinduced interface traps were observed near the SiC valence band edge and just above mid-gap, and field effect channel mobility was reduced by 18-20% following irradiation. Even so, 4HMOSFETs appear to be more radiation tolerant than Si devices.

Improvement of Channel Mobility in 4H-SiC C-Face MOSFETs by H2 Rich Wet Re-Oxidation

2014 ◽  
Vol 778-780 ◽  
pp. 975-978 ◽  
Author(s):  
Mitsuo Okamoto ◽  
Youichi Makifuchi ◽  
Tsuyoshi Araoka ◽  
Masaki Miyazato ◽  
Yoshiyuki Sugahara ◽  
...  
Keyword(s):  
Water Vapor ◽  
Partial Pressure ◽  
Oxidation Rate ◽  
Catalytic Action ◽  
Wet Oxidation ◽  
Interface Traps ◽  
Mos Capacitor ◽  
Channel Mobility ◽  
Vapor Generator ◽  
First Time

4H-SiC(000-1) C-face was oxidized in H2O and H2mixture gas (H2rich wet ambient) for the first time. H2rich wet ambient was formed by the catalytic water vapor generator (WVG) system, where the catalytic action instantaneously enhances the reactivity between H2and O2to produce H2O. The dependence of SiC oxidation rate on the H2O partial pressure was investigated. We fabricated 4H-SiC C-face MOS capacitor and MOSFET by the H2rich wet re-oxidation following the dry O2oxidation. The density of interface traps was reduced and the channel mobility was improved in comparison with the conventional O2rich wet oxidation.

scholarly journals Reducing Interface Traps with High Density Hydrogen Treatment to Increase Passivated Emitter Rear Contact Cell Efficiency

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Chih-Cheng Yang ◽  
Po-Hsun Chen ◽  
Ting-Chang Chang ◽  
Wan-Ching Su ◽  
Sung-Yu Chen ◽  
...  
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Hydrogen Gas ◽  
High Density ◽  
Experimental Result ◽  
Hydrogen Treatment ◽  
Interface Traps ◽  
Electrical Measurements ◽  
Cell Efficiency

AbstractIn this work, a high-density hydrogen (HDH) treatment is proposed to reduce interface traps and enhance the efficiency of the passivated emitter rear contact (PERC) device. The hydrogen gas is compressed at pressure (~ 70 atm) and relatively low temperature (~ 200 °C) to reduce interface traps without changing any other part of the device’s original fabrication process. Fourier-transform infrared spectroscopy (FTIR) confirmed the enhancement of Si–H bonding and secondary-ion mass spectrometry (SIMS) confirmed the SiN/Si interface traps after the HDH treatment. In addition, electrical measurements of conductance-voltage are measured and extracted to verify the interface trap density (Dit). Moreover, short circuit current density (Jsc), series resistance (Rs), and fill factor (F.F.) are analyzed with a simulated light source of 1 kW M−2 global AM1.5 spectrum to confirm the increase in cell efficiency. External quantum efficiency (EQE) is also measured to confirm the enhancement in conversion efficiency between different wavelengths. Finally, a model is proposed to explain the experimental result before and after the treatment.

Shallow Traps at P-Doped SiO2/4H-SiC(0001) Interface

2011 ◽  
Vol 679-680 ◽  
pp. 338-341 ◽  
Author(s):  
Dai Okamoto ◽  
Hiroshi Yano ◽  
Shinya Kotake ◽  
Tomoaki Hatayama ◽  
Takashi Fuyuki
Keyword(s):  
Photoelectron Spectroscopy ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Interface Traps ◽  
Channel Mobility ◽  
X Ray ◽  
Capacitance Voltage ◽  
Shallow Traps

We report on electrical and physical investigations aimed to clarify the mechanisms behind the high channel mobility of 4H-SiC metal–oxide–semiconductor field-effect transistors processed with POCl3 annealing. By low-temperature capacitance–voltage analysis, we found that the shallow interface traps are effectively removed by P incorporation. Using x-ray photoelectron spectroscopy, we found that the three-fold coordinated P atoms exist at the oxide/4H-SiC interface. The overall results suggest that P atoms directly remove the Si–Si bonds and thus eliminate the near-interface traps.

Influence of Annealing, Oxidation and Doping on Conduction-Band near Interface Traps in 4H-SiC Characterized by Low Temperature Conductance Measurements

2015 ◽  
Vol 821-823 ◽  
pp. 476-479
Author(s):  
Stefan Noll ◽  
Martin Rambach ◽  
Michael Grieb ◽  
Dick Scholten ◽  
Anton J. Bauer ◽  
...  
Keyword(s):  
Low Temperature ◽  
Conduction Band ◽  
Nitrogen Doping ◽  
Interface Traps ◽  
Channel Mobility ◽  
High Frequencies ◽  
Inversion Channel ◽  
Very High Frequencies ◽  
Post Implantation ◽  
Very High

Current power MOSFET devices on Silicon Carbide show a limited inversion channel mobility, which can be a result of the expected very high density of interface states near the conduction band . In the current work, the effect of the post implantation annealing temperature, the thermal oxidation and the nitrogen doping of the n-epi layer on the density of these interface traps is investigated using capacity-conductance measurements. Instead of the usage of very high frequencies as used in , in this investigation the measurements were performed in liquid nitrogen to decrease the recharging times of the interface traps.Due to the different processing the samples showed a wide spreading of the inversion channel mobility. The conductance measurements show a characteristic peak caused by the conduction band near interface traps especially for the low temperature measurements. But these traps could not be correlated to the mobility. Instead, a correlation to the nitrogen doping of the epi layer could be observed.

Germanium – Silicon Carbide Heterojunction Diodes – A Study in Device Characteristics with Increasing Layer Thickness and Deposition Temperature

2010 ◽  
Vol 645-648 ◽  
pp. 889-892
Author(s):  
Peter M. Gammon ◽  
Amador Pérez-Tomás ◽  
Michael R. Jennings ◽  
G.J. Roberts ◽  
V.A. Shah ◽  
...  
Keyword(s):  
Deposition Temperature ◽  
Schottky Diodes ◽  
Interface Traps ◽  
High Concentration ◽  
Channel Mobility ◽  
High K ◽  
Heterojunction Diodes ◽  
High K Dielectric ◽  
Germanium Silicon ◽  
Channel Region

SiC schottky diodes take advantage of the material's superior reverse breakdown voltage when compared to Silicon (Si) [1]. However, when considered for MOSFET applications, the high concentration of interface traps at the SiC/SiO2 interface reduce the material's already low channel mobility [2]. Therefore, a Ge/SiC heterojunction solution becomes an attractive prospect, whereby the Ge forms the control region after being epitaxially grown on the SiC. With a well established Ge-High K dielectric technology [3], a carbon-free oxide would exist, leaving a channel-region with a mobility approximately four times that of SiC.

Evaluation of Interface Traps Type, Energy Level and Density of SiC MOSFETs by Means of C-V Curves TCAD Simulations

2020 ◽  
Vol 1004 ◽  
pp. 608-613
Author(s):  
Ilaria Matacena ◽  
Luca Maresca ◽  
Michele Riccio ◽  
Andrea Irace ◽  
Giovanni Breglio ◽  
...  
Keyword(s):  
Energy Level ◽  
Numerical Study ◽  
High Density ◽  
Interface Traps ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Overall Performance ◽  
Tcad Simulations

SiC MOSFETs are promising devices for many power applications. They are replacing Si devices due to the higher performance of SiC material. However, there are some technological issues still unsolved. One of the main problems is the high density of traps at the SiC/SiO2 interface. Traps distribution at such interface is complex and it affects the overall performance of the device. Traps influence both current-voltage and capacitance-voltage characteristics of a SiC MOSFET. The aim of this work is the study of interface traps effects on C-V and I-V curves for a 1200 V SiC MOSFET. The numerical study is adopted to explain the shape of experimental C-V curves of commercial devices.

scholarly journals Physical Characterisation of 3C-SiC(001)/SiO2 Interface Using XPS

2017 ◽  
Vol 897 ◽  
pp. 151-154 ◽  
Author(s):  
Fan Li ◽  
Oliver Vavasour ◽  
Marc Walker ◽  
David M. Martin ◽  
Yogesh K. Sharma ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxidation Process ◽  
Wet Oxidation ◽  
Interface Traps ◽  
Xps Analysis ◽  
Channel Mobility

Normally-on MOSFETs were fabricated on 3C-SiC epilayers using high temperature (1300 °C) wet oxidation process. XPS analysis found little carbon at the MOS interface yet the channel mobility (60 cm2/V.s) is considerably low. Si suboxides (SiOx, x<2) exist at the wet oxidised 3C-SiC/SiO2 interface, which may act as interface traps and degrade the conduction performance.

High Channel Mobility of 4H-SiC MOSFETs Fabricated by Over-Oxidation of the N-/Al-Coimplanted Surface Layer

2009 ◽  
Vol 615-617 ◽  
pp. 765-768 ◽  
Author(s):  
Sergey A. Reshanov ◽  
Svetlana Beljakowa ◽  
Thomas Frank ◽  
Bernd Zippelius ◽  
Michael Krieger ◽  
...  
Keyword(s):  
Surface Layer ◽  
Threshold Voltage ◽  
Hall Mobility ◽  
Electron Mobility ◽  
Room Temperature ◽  
High Mobility ◽  
Interface Traps ◽  
Effective Electron ◽  
Channel Mobility ◽  
Positive Threshold

Conventional MOSFETs and Hall-bar MOSFETs are fabricated side by side by over-oxidation of N-implanted or N-/Al-coimplanted 4H-SiC layers. It is demonstrated that the N-/Al-coimplanted MOSFETs possess a positive threshold voltage at room temperature and reach high values of the channel mobility. The effective electron mobility and Hall mobility in Hall-bar MOSFETs are 31 cm2/Vs and 150 cm2/Vs, respectively, indicating a high density of interface traps in spite of the excellent high mobility values.

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