Low Density of Interface States in n-Type 4H-SiC MOS Capacitors Achieved by Nitrogen Implantation

A surface-near Gaussian nitrogen (N) profile is implanted into n-type 4H-SiC epilayers prior to a standard oxidation process. Depending on the depth of the oxidized layer and on the implanted N concentration, the density of interface states DIT determined in corresponding 4H-SiC MOS capacitors decreases to a minimum value of approx. 1010 cm-2eV-1 in the investigated energy range (EC-(0.1 eV to 0.6 eV)), while the flat-band voltage increases to negative values due to generated fixed positive charges. A thin surface-near layer, which is highly N-doped during the chemical vapour deposition growth, leads to a reduction of DIT only close to the conduction band edge.

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Fabrication of Ta2O5-Si System with Low Density of Interface States and Deep Traps by Plasma Enhanced Liquid Source CVD

10.7567/ssdm.1993.lc-5 ◽

1993 ◽

Author(s):

P. A. Murawala ◽

M. Sawai ◽

T. Tatsuta ◽

O. Tsuji Sz. Fujita ◽

Sg. Fujita

Keyword(s):

Interface States ◽

Low Density ◽

Deep Traps ◽

Liquid Source ◽

Density Of Interface States

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Characterization of MOS Capacitors Fabricated on n-type 4H-SiC Implanted with Nitrogen at High Dose

Materials Science Forum ◽

10.4028/www.scientific.net/msf.556-557.639 ◽

2007 ◽

Vol 556-557 ◽

pp. 639-642 ◽

Cited By ~ 4

Author(s):

Antonella Poggi ◽

Francesco Moscatelli ◽

Yasuto Hijikata ◽

Sandro Solmi ◽

Michele Sanmartin ◽

...

Keyword(s):

Interface State ◽

Interface States ◽

State Density ◽

Conduction Band Edge ◽

High Dose ◽

Wet Oxidation ◽

Nitrogen Implantation ◽

High Concentration ◽

Mos Capacitors ◽

Wide Range

Aiming to minimize the interface state density, we fabricated MOS capacitors on n-type 4H-SiC by using wet oxidation of nitrogen implanted layers. We investigated a wide range of implantation dose, including a high dose able to amorphise a surface SiC layer with the intent to reduce the oxidation time. The oxide quality and the SiO2-SiC interface properties were characterized by capacitance-voltage measurements of the MOS capacitors. The proposed process, in which nitrogen is ion-implanted on SiC layer before a wet oxidation, is effective to reduce the density of interface states near the conduction band edge if a high concentration of nitrogen is introduced at the SiO2-SiC interface. We found that only the nitrogen implanted at the oxide-SiC interface reduces the interface states and we did not observe the generation of fixed positive charges in the oxide as a consequence of nitrogen implantation. Furthermore, the concentration of the slow traps evaluated from the Slow Trap Profiling technique was low and did not depend on the nitrogen implantation fluence.

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Self-terminated Gate Recessing with a Low Density of Interface States and High Uniformity for Enhancement-mode GaN HEMTs

2020 32nd International Symposium on Power Semiconductor Devices and ICs (ISPSD) ◽

10.1109/ispsd46842.2020.9170199 ◽

2020 ◽

Author(s):

Shuai Su ◽

Yaozong Zhong ◽

Yu Zhou ◽

Hongwei Gao ◽

Xiaoning Zhan ◽

...

Keyword(s):

Interface States ◽

Low Density ◽

Enhancement Mode ◽

High Uniformity ◽

Gan Hemts ◽

Density Of Interface States

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Charge transport mechanism in copper phthalocyanine thin films with and without traps

RSC Advances ◽

10.1039/c7ra08316e ◽

2017 ◽

Vol 7 (86) ◽

pp. 54911-54919 ◽

Cited By ~ 10

Author(s):

Varsha Rani ◽

Akanksha Sharma ◽

Pramod Kumar ◽

Budhi Singh ◽

Subhasis Ghosh

Keyword(s):

Thin Films ◽

Charge Transport ◽

Grain Boundaries ◽

Transport Mechanism ◽

Copper Phthalocyanine ◽

Organic Thin Films ◽

Interface States ◽

Charge Transport Mechanism ◽

Density Of Interface States

We investigate the charge transport mechanism in copper phthalocyanine thin films with and without traps. We find that the density of interface states at the grain boundaries can decide the mechanism of charge transport in organic thin films.

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Reduction in the Density of Interface States at the SiO2/4H-SiC Interface after Dry Oxidation in the Presence of Potassium

Materials Science Forum ◽

10.4028/www.scientific.net/msf.679-680.334 ◽

2011 ◽

Vol 679-680 ◽

pp. 334-337 ◽

Cited By ~ 1

Author(s):

Pétur Gordon Hermannsson ◽

Einar Ö. Sveinbjörnsson

Keyword(s):

Energy Distribution ◽

Oxidation Rate ◽

Alkali Metals ◽

Interface States ◽

Significant Enhancement ◽

Interface Traps ◽

Strong Reduction ◽

Dry Oxidation ◽

Density Of Interface States

We report a strong reduction in the density of near-interface traps (NITs) at the SiO2/4H-SiC interface after dry oxidation in the presence of potassium. This is accompanied by a significant enhancement of the oxidation rate. The results are in line with recent investigations of the effect of sodium on oxidation of 4H-SiC. It is evident that both alkali metals enhance the oxidation rate of SiC and strongly influence the energy distribution of interface states.

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