Accurate Characterization of Interface State Density of SiC MOS Structures and the Impacts on Channel Mobility

We focused on the inability of the common high-low method to detect very fast interface states, and developed methods to evaluate such states (CψS method). We have investigated correlation between the interface state density (DIT) evaluated by the CψS method and MOSFET performance, and found that the DIT(CψS) was well reflected in MOSFET performance. Very fast interface states which are generated by nitridation restricted the improvement of subthreshold slope and field-effect mobility.

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Characterization of SiO2/SiC Interface of Phosphorous-Doped MOS Capacitors by Conductance Measurements

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.c5316.098319 ◽

2019 ◽

Vol 8 (3) ◽

pp. 5505-5508

Keyword(s):

Frequency Response ◽

Interface State ◽

Interface States ◽

State Density ◽

Interface State Density ◽

Mos Capacitors ◽

Channel Mobility ◽

Conductance Method ◽

Mos Structures

Interface states of MOS structures capacitors incorporated with low levels of phosphorous have been investigated by conductance and C-ψs method. The frequency response of interface states was observed by the conductance method up to 10 MHz. The correlation between the frequency response of interface states and interface state density determined by C-ψs method was studied. It was found that fast states in phosphorous incorporated samples reduced significantly at high frequency (>5 MHz) while sample annealed with nitrogen remained high up to 10 MHz. The interface state density, Dit of phosphorous incorporated sample near conduction band is lower compared to nitridated sample. These results indicate phosphorous passivation effectively reduces Dit at the SiO2 /SiC interfaces and can be correlated to high channel mobility.

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Characterization of Interface State Density from Subthreshold Slope of MOSFETs at Low Temperatures (≥ 10 K)

Materials Science Forum ◽

10.4028/www.scientific.net/msf.821-823.745 ◽

2015 ◽

Vol 821-823 ◽

pp. 745-748

Author(s):

Hironori Yoshioka ◽

Junji Senzaki ◽

Atsushi Shimozato ◽

Yasunori Tanaka ◽

Hajime Okumura

Keyword(s):

Low Temperatures ◽

Field Effect ◽

Gate Oxide ◽

Interface State ◽

State Density ◽

Interface State Density ◽

Subthreshold Slope ◽

Field Effect Mobility ◽

Peak Field

We have evaluated interface state density (DIT) for EC−ET > 0.00 eV from the subthreshold slope deterioration of MOSFETs at low temperatures. We have compared two n-channel MOSFETs on the C- and a-faces with the gate oxide formed by pyrogenic oxidation followed by annealing in H2. The peak field-effect mobility (µFE,peak) for the C-face MOSFET was 57 cm2V-1s-1 at 300 K, which is lower than the half of 135 cm2V-1s-1 for the a-face MOSFET. We have shown that DIT very close to EC can well explain why µFE for C-face MOSFETs is lower than that for a-face MOSFETs. The value of DIT at 0.00 eV corresponding to the subthreshold slope at 11 K was 1.6×1014 cm-2eV-1 for the C-face MOSFET, which is more than the double of 6.4×1013 cm-2eV-1 for the a-face MOSFET.

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Electrical Properties of High-K LaLuO3 Gate Oxide for SOI MOSFETs

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.276.87 ◽

2011 ◽

Vol 276 ◽

pp. 87-93

Author(s):

Y.Y. Gomeniuk ◽

Y.V. Gomeniuk ◽

A. Nazarov ◽

P.K. Hurley ◽

Karim Cherkaoui ◽

...

Keyword(s):

Electrical Characterization ◽

Gate Oxide ◽

Interface State ◽

Channel Length ◽

State Density ◽

Interface State Density ◽

Mos Capacitors ◽

Channel Mobility ◽

Threshold Voltages

The paper presents the results of electrical characterization of MOS capacitors and SOI MOSFETs with novel high-κ LaLuO3 dielectric as a gate oxide. The energy distribution of interface state density at LaLuO3/Si interface is presented and typical maxima of 1.2×1011 eV–1cm–2 was found at about 0.25 eV from the silicon valence band. The output and transfer characteristics of the n- and p-MOSFET (channel length and width were 1 µm and 50 µm, respectively) are presented. The front channel mobility appeared to be 126 cm2V–1s–1 and 70 cm2V–1s–1 for n- and p-MOSFET, respectively. The front channel threshold voltages as well as the density of states at the back interface are presented.

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Analysis of Interface Trap Density and Channel Mobility in 4H-SiC NMOS Capacitors and Lateral MOSFETs

Materials Science Forum ◽

10.4028/www.scientific.net/msf.897.115 ◽

2017 ◽

Vol 897 ◽

pp. 115-118

Author(s):

Martin Domeij ◽

Jimmy Franchi ◽

Krister Gumaelius ◽

K. Lee ◽

Fredrik Allerstam

Keyword(s):

Threshold Voltage ◽

Interface State ◽

State Density ◽

Interface State Density ◽

Trap Density ◽

Interface Trap Density ◽

Interface Trap ◽

Subthreshold Slope ◽

Gate Oxides ◽

Channel Mobility

Lateral implanted SiC MOSFETs and NMOS capacitors were fabricated and used to extract channel mobility and interface state density DIT for three different gate oxides. DIT values were extracted using the high(1 MHz)-low(1 kHz) method for NMOS capacitors and the subthreshold slope for MOSFETs. The subthreshold slope extraction gave 6-20 times higher DIT values compared to the high-low method, presumably because the high-low method cannot capture the fastest traps [1]. None of the methods resulted in clear proportionality between the inverse channel mobility and DIT. The subthreshold slope gave similar DIT values for samples with different surface p-doping concentrations indicating that the method is not sensitive to the threshold voltage.

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

MRS Proceedings ◽

10.1557/proc-622-t8.7.1 ◽

2000 ◽

Vol 622 ◽

Cited By ~ 1

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.

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Deep-Level-Transient Spectroscopy Characterization of Mobility-Limiting Traps in SiO2/SiC Interfaces on C-Face 4H-SiC

Materials Science Forum ◽

10.4028/www.scientific.net/msf.740-742.477 ◽

2013 ◽

Vol 740-742 ◽

pp. 477-480 ◽

Cited By ~ 7

Author(s):

Tetsuo Hatakeyama ◽

T. Shimizu ◽

T. Suzuki ◽

Y. Nakabayashi ◽

Hajime Okumura ◽

...

Keyword(s):

Conduction Band ◽

Deep Level Transient Spectroscopy ◽

Deep Level ◽

Interface State ◽

State Density ◽

Interface State Density ◽

Channel Mobility ◽

Transient Spectroscopy ◽

Density Of Interface States

Constant-capacitance deep-level-transient spectroscopy (CCDLTS) characterization of traps (or states) in SiO2/SiC interfaces on the C-face was carried out to clarify the cause of low-channel mobility of SiC MOSFETs. CCDLTS measurements showed that the interface-state density (Dit) near the conduction band of SiO2/SiC interfaces fabricated using N2O oxidation was much higher than that of SiO2/SiC interfaces fabricated using wet oxidation. The high density of interface states near the conduction band is likely to be the main cause of the low mobility of MOSFETs fabricated using N2O oxidation.

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Preparation and Characterization of Nitridation Layer on 4H SiC (0001) Surface by Direct Plasma Nitridation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.778-780.631 ◽

2014 ◽

Vol 778-780 ◽

pp. 631-634 ◽

Cited By ~ 1

Author(s):

Yoshiyuki Akahane ◽

Takuo Kano ◽

Kyosuke Kimura ◽

Hiroki Komatsu ◽

Yukimune Watanabe ◽

...

Keyword(s):

Interface State ◽

Nitride Layer ◽

State Density ◽

Interface State Density ◽

Process Temperature ◽

Pure Nitrogen ◽

Interface Property ◽

Plasma Nitridation

A nitride layer was formed on a SiC surface by plasma nitridation using pure nitrogen as the reaction gas at the temperature from 800°C to 1400°C. The surface was characterized by XPS. The XPS measurement showed that an oxinitride layer was formed on the SiC surface by the plasma nitridation. The high process temperature seemed to be effective to activate the niridation reaction. A SiO2film was deposited on the nitridation layer to form SiO2/nitride/SiC structure. The interface state density of the SiO2/nitride/SiC structure was lower than that of the SiO2/SiC structure. This suggested that the nitridation was effective to improve the interface property.

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Characterization of Wet Chemical Atomic Layer Etching of InGaAs

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.314.95 ◽

2021 ◽

Vol 314 ◽

pp. 95-98

Author(s):

Tomoki Hirano ◽

Kenya Nishio ◽

Takashi Fukatani ◽

Suguru Saito ◽

Yoshiya Hagimoto ◽

...

Keyword(s):

Surface Condition ◽

Atomic Layer ◽

Interface State ◽

State Density ◽

Interface State Density ◽

Etching Process ◽

Wet Chemical ◽

Oxide Removal ◽

Atomic Layer Etching

In this work, we characterized the wet chemical atomic layer etching of an InGaAs surface by using various surface analysis methods. For this etching process, H2O2 was used to create a self-limiting oxide layer. Oxide removal was studied for both HCl and NH4OH solutions. Less In oxide tended to remain after the HCl treatment than after the NH4OH treatment, so the combination of H2O2 and HCl is suitable for wet chemical atomic layer etching. In addition, we found that repetition of this etching process does not impact on the oxide amount, surface roughness, and interface state density. Thus, nanoscale etching of InGaAs with no impact on the surface condition is possible with this method.

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