Inversion-type p-channel diamond MOSFET issues

AbstractThis article reviews the state of the art in inversion-type p-channel diamond MOSFETs. We successfully developed the world’s first inversion-channel homoepitaxial and heteroepitaxial diamond MOSFETs. We investigated the dependence of phosphorus concentration (NP) of the n-type body on field-effect mobility (μFE) and interface state density (Dit) for the inversion channel homoepitaxial diamond MOSFETs. With regard to the electrical properties of both the homoepitaxial and heteroepitaxial diamond MOSFETs, they suffer from low μFE and one main reason is high Dit. To improve the interface quality, we proposed a novel technique to form OH-termination by using H-diamond followed by wet annealing, instead of the previous OH-termination formed on O-diamond. We made precise interface characterization for diamond MOS capacitors by using the high-low C–V method and the conductance method, providing further insights into the trap properties at Al2O3/diamond interface, which would be beneficial for performance enhancement of the inversion-type p-channel diamond MOSFETs. Graphic abstract

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Improved Field Effect Mobility in Si-Face 4H-SiC MOSFETs with a Deposited SiNx Interface Layer

Materials Science Forum ◽

10.4028/www.scientific.net/msf.963.469 ◽

2019 ◽

Vol 963 ◽

pp. 469-472 ◽

Cited By ~ 1

Author(s):

Teruaki Kumazawa ◽

Mitsuo Okamoto ◽

Miwako Iijima ◽

Yohei Iwahashi ◽

Shinji Fujikake ◽

...

Keyword(s):

Field Effect ◽

Atomic Layer ◽

Interface Layer ◽

Interface State ◽

State Density ◽

Field Effect Mobility ◽

Optimal Thickness ◽

Interface Quality ◽

Mos Devices ◽

Layer Deposition

The SiO2/SiC interface quality has a significant effect on the performance of 4H-SiC MOS devices. The introduction of nitrogen to the SiO2/SiC interface is a well-known method for reducing the interface state density (Dit). In this study, we introduced nitrogen to the SiO2/SiC interface by forming SiNx films using atomic layer deposition (ALD) and thus improved the interface quality. O2 annealing with a SiNx interface layer of optimal thickness enhanced the field effect mobility.

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Correlation between Field Effect Mobility and Accumulation Conductance at 4H-SiC MOS Interface with Barium

Materials Science Forum ◽

10.4028/www.scientific.net/msf.924.477 ◽

2018 ◽

Vol 924 ◽

pp. 477-481

Author(s):

Kosuke Muraoka ◽

Seiji Ishikawa ◽

Hiroshi Sezaki ◽

Tomonori Maeda ◽

Shinichiro Kuroki

Keyword(s):

Linear Correlation ◽

Field Effect ◽

Interface State ◽

State Density ◽

Interface State Density ◽

Field Effect Mobility ◽

Mos Capacitors

A correlation between field effect mobility and an accumulation conductance has been investigated at 4H-SiC MOS interface with barium. 4H-SiC n-channel MOSFETs and n-type MOS capacitors were fabricated with a barium-introduced SiO2and a conventional dry SiO2. The field effect mobility was enhanced by introducing the barium-introduced SiO2. It is found that there is a linear correlation between the mobility and the accumulation conductance. The MOS interface of the barium-introduced SiO2had a lower interface state density of 2×1011cm-2eV-1than that of the conventional dry SiO2.

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Investigation of Interface State Density with Varied SiO2 Thickness in La2O3/SiO2/4H-SiC MOS Capacitors

Materials Science Forum ◽

10.4028/www.scientific.net/msf.858.689 ◽

2016 ◽

Vol 858 ◽

pp. 689-692 ◽

Cited By ~ 1

Author(s):

Yu Cheng Wang ◽

Yu Ming Zhang ◽

Ren Xu Jia

Keyword(s):

Photoelectron Spectroscopy ◽

Lattice Mismatch ◽

Atomic Layer ◽

Interface State ◽

Carbon Cluster ◽

State Density ◽

Oxide Semiconductor ◽

Interface Quality ◽

Mos Capacitors ◽

Layer Deposition

SiO2 with varying thickness (0, 4.45, and 8.05 nm) were grown on n type 4H-SiC epilayer by thermal oxidation and La2O3 were stacked on them using atomic layer deposition (ALD). The La2O3/SiO2/4H-SiC metal-oxide-semiconductor (MOS) capacitors were analyzed by X-ray photoelectron spectroscopy (XPS) and capacitance-voltage (C-V) measurements. C-V curves show that introducing an ultrathin SiO2 can reduce the effect of lattice mismatch of La2O3/4H-SiC structure and then improve interface property. However, the interface quality is reduced as SiO2 was grown thicker. XPS data show that more carbon cluster remains at the interfacial between SiO2 and 4H-SiC as the oxidation time increases.

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Progress in GaN MOSFET Technology

Materials Science Forum ◽

10.4028/www.scientific.net/msf.600-603.1263 ◽

2008 ◽

Vol 600-603 ◽

pp. 1263-1268 ◽

Cited By ~ 1

Author(s):

T. Paul Chow ◽

W. Huang ◽

T. Khan ◽

K. Matocha ◽

Y. Wang

Keyword(s):

Field Effect ◽

Interface State ◽

Orientation Dependence ◽

State Density ◽

Interface State Density ◽

Field Effect Mobility ◽

Mos Capacitors ◽

Enhancement Mode ◽

Current Collapse ◽

Non Destructive

GaN MOS capacitors were characterized to optimize the electric properties of SiO2/GaN interface. With optimized anneal conditions, an interface state density of 3.8×1010/cm2-eV was estimated at 0.19 eV near the conduction band and decreases deeper into the band gap. Enhancement-mode GaN MOSFETs were experimentally demonstrated on both p and n GaN epilayer with record high field-effect mobility of 167 cm2/V-s. Lateral RESURF-type GaN MOSFETs exhibit non-destructive high voltage (up to 940V) blocking capabilities. Other characterization including mobility orientation dependence, MOS-gated Hall mobility, current collapse and an NMOS inverter utilizing E/D mode GaN MOSFETs have also been experimentally demonstrated.

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Improvement of SiO2/4H-SiC Interface Quality by Post-Oxidation Annealing in N2 at High-Temperatures

Materials Science Forum ◽

10.4028/www.scientific.net/msf.858.627 ◽

2016 ◽

Vol 858 ◽

pp. 627-630 ◽

Cited By ~ 1

Author(s):

Atthawut Chanthaphan ◽

Yen Hung Cheng ◽

Takuji Hosoi ◽

Takayoshi Shimura ◽

Heiji Watanabe

Keyword(s):

Photoelectron Spectroscopy ◽

Annealing Temperature ◽

Electrical Characterization ◽

Practical Method ◽

Interface State ◽

State Density ◽

Interface Quality ◽

Mos Capacitors ◽

X Ray ◽

Mos Devices

The efficient and practical method for SiO2/4H-SiC interface improvement using post-oxidation annealing (POA) in pure N2 ambient was studied by means of x-ray photoelectron spectroscopy (XPS) analysis and electrical characterization. SiC-MOS capacitors with slope-shaped thermal oxides were used to investigate optimal conditions for interface nitridation. It was found that the amount of nitrogen atoms incorporated into the interfaces increased when raised the annealing temperature up to 1400°C, and thin oxide (< 30 nm) was used. Furthermore, N2-POA at 1400°C was proven to be very promising as equivalent to NO-POA in terms of reduced interface state density of SiC-MOS devices.

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Surface Treatment of 4H-SiC MOSFETs Prior to Al2O3 Deposition

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1004.541 ◽

2020 ◽

Vol 1004 ◽

pp. 541-546

Author(s):

Muhammad Idzdihar Idris ◽

Alton B. Horsfall

Keyword(s):

Surface Treatment ◽

Field Effect ◽

High Performance ◽

Interface State ◽

State Density ◽

Interface State Density ◽

Surface Treatments ◽

Flat Band ◽

Field Effect Mobility ◽

Mos Capacitors

The effect of surface treatments prior to the deposition of Al2O3 is performed on 4H-SiC MOS capacitors and MOSFETs. 40 nm of Al2O3 were deposited on 4H-SiC using atomic layer deposition (ALD) as a gate dielectric. Different surface treatments were used to investigate the capacitance-voltage and current-voltage characteristics on MOS capacitors and MOSFETs respectively, including the important parameters such as interface state density, flat band voltage, threshold voltage and field-effect mobility. Forming gas annealing and rapid oxidation processes were found to be effective in reducing the interface state density and results in high field-effect mobility with peak field-effect mobility of 130 cm2Vs-1. The experimental results obtained manifest that the surface treatment prior to Al2O3 deposition is critical to producing high performance of 4H-SiC MOSFETs.

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Effect of Post-Oxidation Annealing in Wet O2 and N2O Ambient on Thermally Grown SiO2/4H-SiC Interface for P-Channel MOS Devices

Materials Science Forum ◽

10.4028/www.scientific.net/msf.717-720.709 ◽

2012 ◽

Vol 717-720 ◽

pp. 709-712 ◽

Cited By ~ 5

Author(s):

Shuji Katakami ◽

Manabu Arai ◽

Kensuke Takenaka ◽

Yoshiyuki Yonezawa ◽

Hitoshi Ishimori ◽

...

Keyword(s):

Interfacial Properties ◽

Interface State ◽

State Density ◽

Interface State Density ◽

Promising Method ◽

Mos Capacitors ◽

Channel Mobility ◽

Mos Devices ◽

Inversion Channel ◽

P Type

We investigated the effect of post-oxidation annealing in wet O2 and N2O ambient, following dry O2 oxidation on the SiC MOS interfacial properties by using p-type MOS capacitors. The interfacial properties were dramatically improved by the introduction of hydrogen or nitrogen atoms into the SiO2/SiC interface, in each POA process. Notably, the N2O-POA process at 1200 °C or higher reduced the interface state density more effectively than the wet-O2-POA process, and offers a promising method to further improve the inversion channel mobility of p-channel SiC MOS devices.

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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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The Correlation between the Reduction of Interface State Density at the SiO2/SiC Interface and the NO Post-Oxide-Annealing Conditions

Materials Science Forum ◽

10.4028/www.scientific.net/msf.954.104 ◽

2019 ◽

Vol 954 ◽

pp. 104-108

Author(s):

Heng Yu Xu ◽

Cai Ping Wan ◽

Jin Ping Ao

Keyword(s):

Mass Spectrometry ◽

Secondary Ion Mass Spectrometry ◽

Interface State ◽

State Density ◽

Interface State Density ◽

Mos Capacitors ◽

Annealing Conditions ◽

N Concentration ◽

Higher Temperature ◽

Secondary Ion

We fabricated SiO2/4H-SiC (0001) MOS capacitors with oxidation temperature at 1350°C, followed by post-oxide-annealing (POA) in NO simply by the control of POA temperatures and times. A correlation between the reduction of interface state density and the increasing of N concentration at the interface has been indicated by C-ψs measurement and secondary ion mass spectrometry (SIMS). The SiO2/4H-SiC interface density decreased when POA temperature was elevated, and the sample annealed at 1300°C for 30min showed the lowest interface state density about 1.5×1012 cm-2eV-1 at Ec-E=0.3 eV when the N concentration is 11.5×1020 cm-3. Meanwhile, the SiO2 /4H-SiC interface annealed at 1200°C for 120min showed the highest N concentration at the 4H-SiC/SiO2 interface is 12.5×1020 cm-3, whereas the interface state density is 2.5×1012 cm-2eV-1 at Ec-E=0.3 eV higher than 1300°C for 30min. The results suggested that higher temperature POA might be much more efficiency in decreased the 4H-SiC MOS interface density with increasing the N area concentration.

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