Cryogenic Characterization of NH3 Post Oxidation Annealed 4H-SiC Trench MOSFETs

2019 ◽  
Vol 963 ◽  
pp. 175-179
Author(s):  
Judith Berens ◽  
Gregor Pobegen ◽  
Thomas Aichinger ◽  
Gerald Rescher ◽  
Tibor Grasser
Keyword(s):  
Nitric Oxide ◽  
Conduction Band ◽  
Thermal Emission ◽  
Current Method ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Interface Traps ◽  
Two Peaks ◽  
Trap Levels

We employed the thermal dielectric relaxation current method (TDRC) for the cryogenic characterization of ammonia (NH3) post oxidation annealed 4H silicon carbide (4H-SiC) trench MOSFETs. We studied differences and similarities between annealing in nitric oxide (NO) and NH3. In NO and NH3 annealed trench MOSFETs, the same type of traps was found near the conduction band edge of 4H-SiC. The TDRC-signal consists of two peaks caused by interface states with a thermal emission barrier of 0.13 eV and near interface traps (NITs) with an emission barrier of approximately 0.3 eV. Significantly more interface traps close to the conduction band edge were found for the NH3 annealed devices compared to the NO annealed ones. Our TDRC results indicate that NH3 post oxidation anneal (POA) affects trap levels in a different way than NO POA.

A Study of Deep Energy-Level Traps at the 4H-SiC/SiO2 Interface and Their Passivation by Hydrogen

2008 ◽  
Vol 600-603 ◽  
pp. 755-758 ◽  
Author(s):  
Fredrik Allerstam ◽  
Einar Ö. Sveinbjörnsson
Keyword(s):  
Energy Level ◽  
Conduction Band ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Interface Traps ◽  
Enhanced Oxidation ◽  
Transient Spectroscopy

This study is focused on characterization of deep energy-level interface traps formed during sodium enhanced oxidation of n-type Si face 4H-SiC. The traps are located 0.9 eV below the SiC conduction band edge as revealed by deep level transient spectroscopy. Furthermore these traps are passivated using post-metallization anneal at 400°C in forming gas ambient.

Characterization of Localized Density of States in Intrinsic a-Si and poly-Si Films by Transient Voltage Spectroscopy

1995 ◽  
Vol 377 ◽  
Author(s):  
G. Kawachi ◽  
M. Ishii ◽  
T. Tanaka ◽  
N. Konishi
Keyword(s):  
Conduction Band ◽  
Density Of States ◽  
Band Edge ◽  
Conduction Band Edge ◽  
High Impedance ◽  
Pool Model ◽  
Transient Voltage ◽  
Mis Diode ◽  
Si Films

ABSTRACTThe localized density of states (LDOS) at interfaces between intrinsic silicon and silicon nitride (Si3N4 films are studied using transient voltage spectroscopy (TVS). In the TVS technique, the transient of the voltage across a MIS-diode after a trap filling voltage pulse is measured using a high-impedance voltage probe. This allows us to make a precise measurement of the LDOS at undoped Si/insulator interfaces. The LDOS in a-Si:H/Si3N4systems has a broad peak around the energy of 0.9 eV below the conduction-band edge. A modification of the LDOS at a-Si:H/Si3N4 interfaces by bias-annealing is clearly observed using this technique. The results are consistent with the defect pool model. The LDOS in laser annealed poly-Si/Si3N4 systems has a peak centered 0.6eV below the conduction-band edge, which seems to be the Si dangling bond states in the poly-Si films.

scholarly journals Characterization of traps at nitrided SiO2/SiC interfaces near the conduction band edge by using Hall effect measurements

2017 ◽  
Vol 10 (4) ◽  
pp. 046601 ◽  
Author(s):  
Tetsuo Hatakeyama ◽  
Yuji Kiuchi ◽  
Mitsuru Sometani ◽  
Shinsuke Harada ◽  
Dai Okamoto ◽  
...  
Keyword(s):  
Hall Effect ◽  
Conduction Band ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Hall Effect Measurements

The Effects of Post-Oxidation Anneal Conditions on Interface State Density Near the Conduction Band Edge and Inversion Channel Mobility for SiC MOSFETs

2000 ◽  
Vol 622 ◽  
Author(s):  
G.Y. Chung ◽  
C.C. Tin ◽  
J. R. Williams ◽  
K. McDonald ◽  
M. Di Ventra ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Conduction Band ◽  
Interface State ◽  
Interface States ◽  
State Density ◽  
Interface State Density ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Channel Mobility ◽  
Inversion Channel

ABSTRACTResults are reported for the passivation of interface states near the conduction band edge in n-4H-SiC using post-oxidation anneals in nitric oxide, ammonia and forming gas (N2/5%H2). Anneals in nitric oxide and ammonia reduce the interface state density significantly, while forming gas anneals are largely ineffective. Results suggest that interface states in SiO2/SiC and SiO2/Si have different origins, and a model is described for interface state passivation by nitrogen in the SiO2/SiC system. The inversion channel mobility of 4H-SiC MOSFETs increases with the NO annealing.

Characteristics of MOS Capacitors with NO and POCl3 Annealed Gate Oxides on (0001), (11-20) and (000-1) 4H-SiC

2015 ◽  
Vol 821-823 ◽  
pp. 500-503 ◽  
Author(s):  
Sauvik Chowdhury ◽  
Kensaku Yamamoto ◽  
Collin W. Hitchcock ◽  
T. Paul Chow
Keyword(s):  
Conduction Band ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Interface Traps ◽  
Conductance Measurement ◽  
Gate Oxides ◽  
Mos Capacitors ◽  
Donor Type

MOS capacitors have been fabricated on (0001), (11-20) and (000-1) oriented 4H-SiC under different post-oxidation anneal (POA) conditions. 100 MHz conductance measurement shows the generation of very fast donor-type interface traps after NO anneal for both Si-face (0001) and a-face (11-20), but not on C-face (000-1). Fast traps were not observed in POCl3annealed samples for any orientation. Smallest Dit(at 0.2 eV below conduction band edge) was obtained on Si-face using POCl3anneal (1.4x1011cm-2eV-1), on a-face using NO anneal (2.5x1011cm-2eV-1) and on C-face using POCl3anneal (4.5x1012cm-2eV-1).

Effect of Band-Edge Interface Traps and Transition Region Mobility on Transport in 4H-SiC MOSFETs

2010 ◽  
Vol 645-648 ◽  
pp. 975-978 ◽  
Author(s):  
Siddharth Potbhare ◽  
Akin Akturk ◽  
Neil Goldsman ◽  
Aivars J. Lelis ◽  
Sarit Dhar ◽  
...  
Keyword(s):  
Conduction Band ◽  
Transition Layer ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Interface Traps ◽  
Conduction Band Electron ◽  
Mos Devices ◽  
Strong Inversion ◽  
Parameter Values ◽  
Very High

We present physics based models for the occupation of interface traps and the mobility of the transition layer found in 4H-SiC MOSFETs and extract values for the same using combined numerical simulation and experimental characterization. The Si-C-O transition layer found in 4H-SiC MOS devices is electrically modeled as having a doping dependent mobility that is different from the regular bulk 4H-SiC bulk mobility. Compared to the high intrinsic bulk mobility of 4H-SiC, the transition layer intrinsic mobility was extracted to be approximately 165cm2/Vs. The occurrence of the excessive high density of interface traps near the conduction band edge led us to develop a new model for the occupation of traps lying inside the conduction band itself. Due to the conduction band trap densities being comparable to the conduction band electron states, a non-zero probability exists for their occupation, which causes the occupied trap densities to be very high in strong inversion. Detailed numerical simulations and corroboration with experiment have been performed to calibrate the models and extract physical parameter values.

scholarly journals Conduction Band Edge Energy Profile Probed by Hall Offset Voltage in InGaZnO Thin Films

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 822
Author(s):  
Hyo-Jun Joo ◽  
Dae-Hwan Kim ◽  
Hyun-Seok Cha ◽  
Sang-Hun Song
Keyword(s):  
Magnetic Field ◽  
Electron Density ◽  
Conduction Band ◽  
Electron System ◽  
Band Edge ◽  
Conduction Band Edge ◽  
Offset Voltage ◽  
Three Samples ◽  
Dimensional Electron System ◽  
Longitudinal Distance

We measured and analyzed the Hall offset voltages in InGaZnO thin-film transistors. The Hall offset voltages were found to decrease monotonously as the electron densities increased. We attributed the magnitude of the offset voltage to the misalignment in the longitudinal distance between the probing points and the electron density to Fermi energy of the two-dimensional electron system, which was verified by the coincidence of the Hall voltage with the perpendicular magnetic field in the tilted magnetic field. From these results, we deduced the combined conduction band edge energy profiles from the Hall offset voltages with the electron density variations for three samples with different threshold voltages. The extracted combined conduction band edge varied by a few tens of meV over a longitudinal distance of a few tenths of µm. This result is in good agreement with the value obtained from the analysis of percolation conduction.

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