scholarly journals Influence of Hydrogen-Nitrogen Hybrid Passivation on the Gate Oxide Film of n-Type 4H-SiC MOS Capacitors

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1449
Author(s):  
Yifan Jia ◽  
Shengjun Sun ◽  
Xiangtai Liu ◽  
Qin Lu ◽  
Ke Qin ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Gate Oxide ◽  
Sio2 Film ◽  
Interface Traps ◽  
Hydrogen Atoms ◽  
Mos Capacitors ◽  
Bias Stress ◽  
Current Voltage ◽  
Short Time ◽  
Secondary Ion

Hydrogen-nitrogen hybrid passivation treatment for growing high-property gate oxide films by high-temperature wet oxidation, with short-time NO POA, is proposed and demonstrated. Secondary ion mass spectroscopy (SIMS) measurements show that the proposed method causes hydrogen and appropriate nitrogen atoms to accumulate in Gaussian-like distributions near the SiO2/SiC interface. Moreover, the hydrogen atoms are also incorporated into the grown SiO2 layer, with a concentration of approximately 1 × 1019 cm−3. The conductance characteristics indicate that the induced hydrogen and nitrogen passivation atoms near the interface can effectively reduce the density of interface traps and near-interface traps. The current-voltage (I-V), X-ray photoelectron spectroscopy (XPS), and time-dependent bias stress (TDBS) with ultraviolet light (UVL) irradiation results demonstrate that the grown SiO2 film with the incorporated hydrogen passivation atoms can effectively reduce the density of oxide electron traps, leading to the barrier height being improved and the leakage current being reduced.

scholarly journals A Temperature Independent Effect of Near-Interface Traps in 4H-SiC MOS Capacitors

2019 ◽  
Vol 963 ◽  
pp. 236-239 ◽  
Author(s):  
Peyush Pande ◽  
Sima Dimitrijev ◽  
Daniel Haasmann ◽  
Hamid Amini Moghadam ◽  
Philip Tanner ◽  
...  
Keyword(s):  
Conduction Band ◽  
Direct Measurement ◽  
Measurement Technique ◽  
Energy Levels ◽  
Gate Oxide ◽  
Independent Effect ◽  
Interface Traps ◽  
Mos Capacitors ◽  
Temperature Bias ◽  
Bias Stress

In this paper we report temperature independent near-interface traps (NITs) in the gate oxide of N-type MOS capacitors. The measurements were performed by a recently developed direct-measurement technique, which detected NITs with energy levels between 0.13 eV to 0.23 eV above the bottom of conduction band. These traps are also spatially localized close to the SiC surface, as evidenced by the fact that they are not observed at measurement frequencies below 6 MHz. The temperature independence indicates that this localized defect is different from the usually observed NITs whose density is increased by temperature-bias stress.

Study of the current–voltage characteristics in MOS capacitors with Si-implanted gate oxide

1999 ◽  
Vol 43 (3) ◽  
pp. 555-563 ◽  
Author(s):  
Etsumasa Kameda ◽  
Toshihiro Matsuda ◽  
Yoshiko Emura ◽  
Takashi Ohzone
Keyword(s):  
Gate Oxide ◽  
Mos Capacitors ◽  
Current Voltage ◽  
Current Voltage Characteristics

Laser Photochemical Vapour Deposition of Epitaxial Ge Films on GaAs from GeH4 Using NH3 as a Sensitiser

1988 ◽  
Vol 129 ◽  
Author(s):  
C.J. Kiely ◽  
C. Jones ◽  
V. Tavitian ◽  
J.G. Eden
Keyword(s):  
Growth Rate ◽  
Photoelectron Spectroscopy ◽  
Vapour Deposition ◽  
Film Growth ◽  
Hydrogen Abstraction ◽  
Auger Spectroscopy ◽  
Hydrogen Atoms ◽  
Production Of Hydrogen ◽  
Substrate Temperatures ◽  
Secondary Ion

ABSTRACTThe viability of ammonia as a sensitiser for the epitaxial growth of Ge on GaAs by laser photochemical vapour deposition (LPVD) has been investigated. Specifically NH3/GeH4/He (0.8/5/95 sccm, 5.5 Torr total pressure) mixtures have been irradiated by a 193nm ArF excimer laser in parallel geometry for substrate temperatures, Ts<400°C. As evidenced by a dramatic acceleration in Ge film growth rate, the NH3 efficiently couples the laser radiation to the GeH4 precursor molecule. The microstructures of LPVD Ge films grown with and without NH3 have been examined by TEM, and the epitaxial nature of both types of films has been verified, although some subtle differences are noted. Chemical analysis of the deposited films has been carried out using Auger spectroscopy, X-ray photoelectron spectroscopy and secondary ion mass spectroscopy. Our results show that there is little or no nitrogen incorporation into the Ge films grown in the presence of NH3, and that hydrogen contamination in our films is minimal. The beneficial effect of NH3 on the growth rate of LPVD Ge films is attributed to the photolytic production of hydrogen atoms which efficiently decompose GeH4 by hydrogen abstraction collisions.

Conduction Mechanisms at SiO2/4H-SiC Interfaces in MOS-Based Devices Subjected to Post Deposition Annealing in N2O

2016 ◽  
Vol 858 ◽  
pp. 705-708
Author(s):  
Patrick Fiorenza ◽  
Filippo Giannazzo ◽  
Alessia Frazzetto ◽  
Alfio Guarnera ◽  
Mario Saggio ◽  
...  
Keyword(s):  
Gate Oxide ◽  
Temperature Dependent ◽  
Post Deposition Annealing ◽  
Mos Capacitors ◽  
Gate Current ◽  
Conduction Mechanisms ◽  
Current Voltage ◽  
Hole Conduction ◽  
Current Conduction ◽  
Post Deposition

This paper reports on the conduction mechanisms through the gate oxide and trapping effects at SiO2/4H-SiC interfaces in MOS-based devices subjected to post deposition annealing in N2O. The phenomena were studied by temperature dependent current–voltage measurements. The analysis of both n and p-MOS capacitors and of n-channel MOSFETs operating in the “gate-controlled-diode” configuration revealed an anomalous hole conduction behaviour through the SiO2/4H-SiC interface, with the onset of current conduction moving towards more negative values during subsequent voltage sweeps. The observed gate current instabilities upon subsequent voltage sweeps were deeply investigated by temperature dependent cyclic gate current measurements. The results were explained by the charge-discharge mechanism of hole traps in the oxide.

A Comparison of Active Near-Interface Traps in Nitrided and As-Grown Gate Oxides by the Direct Measurement Technique

2020 ◽  
Vol 1004 ◽  
pp. 635-641
Author(s):  
Peyush Pande ◽  
Sima Dimitrijev ◽  
Daniel Haasmann ◽  
Hamid Amini Moghadam ◽  
Philip Tanner ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Comparative Analysis ◽  
Direct Measurement ◽  
Measurement Technique ◽  
Measurement Method ◽  
Gate Oxide ◽  
Interface Traps ◽  
Gate Oxides ◽  
Mos Capacitors ◽  
Direct Measurement Method

This paper presents a comparative analysis of the electrically active near-interface traps, energetically located above the bottom of conduction band. Two different samples of N-type SiC MOS capacitors were fabricated with gate oxides grown in (1) dry O2 (as-grown) and (2) dry O2 annealed in nitric oxide (nitride). Measurements performed by the direct measurement method revealed that the traps located further away from the SiO2/SiC interface are removed by nitridation. A spatially localized behaviour of NITs is observed only in the nitrided gate oxide but not in the as-grown gate oxide.

The Effect of Silicide Formation on the Electrical Properties of Gate Oxides

1992 ◽  
Vol 260 ◽  
Author(s):  
J. P. Gambino ◽  
B. Cunningham ◽  
D. A. Buchanan
Keyword(s):  
Gate Oxide ◽  
Interface State ◽  
State Density ◽  
Breakdown Field ◽  
Rapid Thermal Anneal ◽  
Gate Oxides ◽  
Mos Capacitors ◽  
Oxide Breakdown ◽  
Current Voltage ◽  
Capacitance Voltage

ABSTRACTCoSi2, or TiSi2 formation on gate polysilicon can degrade the current-voltage and capacitance-voltage characteristics of MOS capacitors. Degradation of the gate oxide breakdown field is much more severe for capacitors with TiSi2 than for those with COSi2 TEM reveals evidence for a reaction at the interface between TiSi2 and SiO2, whereas there is no observable reaction between COSi2 and SiO2- The low breakdown fields for devices with TiSi2 may be due to thinning of the gate oxide by the interfacial reaction or mechanical deformation. A high density of electron traps and a small reduction in the breakdown field is observed when COSi2 contacts the gate, possibly due to a compressive stress in the oxide exerted by the suicide. In addition, an increase in the interface state density at the Si-SiO2 interface is seen for all samples exposed to a rapid thermal anneal (RTA) at 800°C, possibly due to the release of H from dangling bonds.

Investigation of Oxide Films Prepared by Direct Oxidation of C-Face 4H-SiC in Nitric Oxide

2010 ◽  
Vol 645-648 ◽  
pp. 515-518 ◽  
Author(s):  
Dai Okamoto ◽  
Hiroshi Yano ◽  
Yuki Oshiro ◽  
Tomoaki Hatayama ◽  
Yukiharu Uraoka ◽  
...  
Keyword(s):  
Field Effect ◽  
High Performance ◽  
Room Temperature ◽  
Field Effect Transistors ◽  
Gate Oxide ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Interface Traps ◽  
Direct Oxidation ◽  
Mos Capacitors

Characteristics of metal–oxide–semiconductor (MOS) capacitors and MOS field-effect transistors (MOSFETs) fabricated by direct oxidation of C-face 4H-SiC in NO were investigated. It was found that nitridation of the C-face 4H-SiC MOS interface generates near-interface traps (NITs) in the oxide. These traps capture channel mobile electrons and degrade the performance of MOSFETs. The NITs can be reduced by unloading the samples at room temperature after oxidation. It is important to reduce not only the interface states but also the NITs to fabricate high-performance C-face 4H-SiC MOSFETs with nitrided gate oxide.

The Effect of Nitridation on SiC MOS Oxides as Evaluated by Charge Pumping

2008 ◽  
Vol 600-603 ◽  
pp. 743-746 ◽  
Author(s):  
Daniel B. Habersat ◽  
Aivars J. Lelis ◽  
J.M. McGarrity ◽  
F. Barry McLean ◽  
Siddharth Potbhare
Keyword(s):  
Gate Oxide ◽  
Interface Trap Density ◽  
Interface Trap ◽  
Interface Traps ◽  
Strong Reduction ◽  
Large Shift ◽  
Mos Capacitors ◽  
Charge Pumping ◽  
Nitridation Process ◽  
Flatband Voltage

We have analyzed the effect of post-oxidation nitride anneals (usually with either NO or N2O gases) on SiC MOSFETs. Two 4H:SiC wafers were identically prepared except that one wafer had a nitridation anneal after the gate oxide was formed, while the other was tested as-oxidized. We compared the two processes by making measurements on lateral MOSFETs and MOS capacitors using ID-VGS, C-V, and charge pumping. There was no change in either flatband voltage or interface trap density near the valence band, suggesting that the net fixed charge remained constant (within a few 1011cm-2). However, there was a large shift in the threshold voltage which, when combined with the C-V results, indicates a strong reduction of interface traps near the conduction band of roughly 6.0x1012cm-2 by using the nitridation process. The charge pumping measurements also showed a strong reduction of interface traps. Charge pumping measured a trapping density of 2.5x1012cm-2 for the as-oxidized samples and 5.3x1011cm-2 for the nitrided samples. The frequency-dependence of the charge pumping signal also indicates a spatial distribution of traps, with volumetric trap densities of roughly 1.3x1019cm-3 over 25Å on as-oxidized and 3.8x1018cm-3 over 19Å for nitrided.

Time-Dependent Bias Stress-Induced Instability of SiC MOS Devices

2006 ◽  
Vol 911 ◽  
Author(s):  
Aivars Lelis ◽  
Daniel Habersat ◽  
Fatimat Olaniran ◽  
Brian Simons ◽  
James McGarrity ◽  
...  
Keyword(s):  
Electron Tunneling ◽  
Gate Oxide ◽  
Time Dependent ◽  
Gate Bias ◽  
Mos Capacitors ◽  
Bias Stress ◽  
Mos Devices ◽  
Flatband Voltage ◽  
Mobile Ions ◽  
Gate Bias Stress

AbstractWe have observed a gate-bias stress induced instability in both the threshold voltage of SiC MOSFETs and the flatband voltage of SiC MOS capacitors. The magnitude of this bias stress-induced instability generally increases linearly with log time, with no saturation of the effect observed, even out to 100,000 seconds. The magnitude also increases with increasing gate field. A positive gate-bias stress causes a positive shift and a negative gate-bias stress causes a negative shift, consistent with electron tunneling into or out of oxide traps near the SiC / SiO2 interface as opposed to mobile ions drifting across the gate oxide. The effect is repeatable.

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