Effect of Atomic Structure at the Epitaxial CaF2 /Si(111) Interface on Electrical Properties

1987 ◽  
Vol 102 ◽  
Author(s):  
J.L. Batstone ◽  
Julia M. Phillips ◽  
E.C. Hunke

ABSTRACTHigh resolution electron microscopy has been used to determine the atomic structure at the epitaxial CaF2 /Si(111) interface before and after a rapid thermal anneal. Direct Ca-Si bonding at the interface, with 8-fold coordinated Ca atoms is observed in as-grown layers. Fluorine is preferentially removed from the interface during a rapid thermal anneal leaving 5-fold coordinated Ca atoms. A dramatic improvement in the electrical properties of the interface is observed after annealing. The measured interface state density is reduced from ≳1013 cm−2 to ≲1011cm−2. This has been correlated with the removal of F from the interface. No evidence for direct F-Si bonding is observed.

2016 ◽  
Vol 858 ◽  
pp. 663-666
Author(s):  
Marilena Vivona ◽  
Patrick Fiorenza ◽  
Tomasz Sledziewski ◽  
Alexandra Gkanatsiou ◽  
Michael Krieger ◽  
...  

In this work, the electrical properties of SiO2/SiC interfaces onto a 2°-off axis 4H-SiC layer were studied and validated through the processing and characterization of metal-oxide-semiconductor (MOS) capacitors. The electrical analyses on the MOS capacitors gave an interface state density in the low 1×1012 eV-1cm-2 range, which results comparable to the standard 4°-off-axis 4H-SiC, currently used for device fabrication. From Fowler-Nordheim analysis and breakdown measurements, a barrier height of 2.9 eV and an oxide breakdown of 10.3 MV/cm were determined. The results demonstrate the maturity of the 2°-off axis material and pave the way for the fabrication of 4H-SiC MOSFET devices on this misorientation angle.


2017 ◽  
Vol 897 ◽  
pp. 340-343 ◽  
Author(s):  
Atthawut Chanthaphan ◽  
Yoshihito Katsu ◽  
Takuji Hosoi ◽  
Takayoshi Shimura ◽  
Heiji Watanabe

Surface morphology and electrical properties of silicon dioxide (SiO2) on 4H-SiC substrates formed by metal-enhanced oxidation (MEO) using barium (Ba) atoms were systematically investigated. It was found that severe surface roughening caused by Ba-MEO can be suppressed by using SiO2 capping prior to MEO. The Ba atoms at the SiO2/SiC interface were found to diffuse to the oxide surface through the deposited SiO2 capping layer, and then the Ba density reduced to ~1014 cm-2 before stable MEO. The resulting SiO2/SiC interface showed the reduced interface state density but the insulating property of the oxides was significantly degraded.


2015 ◽  
Vol 821-823 ◽  
pp. 773-776 ◽  
Author(s):  
Ruggero Anzalone ◽  
Stefania Privitera ◽  
Alessandra Alberti ◽  
Nicolo’ Piluso ◽  
Patrick Fiorenza ◽  
...  

The effect of the crystal quality and surface morphology on the electrical properties of MOS capacitors has been studied in devices manufactured on 3C-SiC epitaxial layers grown on Silicon (100) substrate. The interface state density, which represents one of the most important parameters for the 3C-SiC MOSFET development, has been determined through capacitance measurements. A cross-correlation between High Resolution X-ray Diffraction, AFM analysis and electrical conductance measurements has allowed determining the relationship between the crystalline quality and the interface state density. By improving the crystalline quality, a decrease of the interface state density down to 1010cm-2eV-1was observed.


Author(s):  
R. Padma ◽  
V. Rajagopal Reddy

The electrical properties of the Ir/Ru Schottky contacts on n-InGaN have been investigated by current-voltage (I-V), capacitance-voltage (C-V), capacitance-frequency (C-f) and conductance-frequency (G-f) measurements. The obtained mean barrier height and ideality factor from I-V are 0.61 eV and 1.89. The built-in potential, doping concentration and barrier height values are also estimated from the C-V measurements and the corresponding values are 0.62 V, 1.20x1017 cm-3 and 0.79 eV, respectively. The interface state density (NSS) obtained from forward bias I-V characteristics by considering the series resistance (RS) values are lower without considering the series resistance (RS). Furthermore, the interface state density (NSS) and relaxation time (tau) are also calculated from the experimental C-f and G-f measurements. The NSS values obtained from the I-V characteristics are almost three orders higher than the NSS values obtained from the C-f and G-f measurements. The experimental results depict that NSS and tau are decreased with bias voltage. The frequency dependence of the series resistance (RS) is attributed to the particular distribution density of interface states. DOI: 10.21883/FTP.2017.12.45189.8340


1989 ◽  
Vol 145 ◽  
Author(s):  
Q.-D. Qian ◽  
J. Qiu ◽  
M. Kobayashi ◽  
R.L. Gunshor ◽  
L.A. Kolodziejski ◽  
...  

AbstractThe electrical properties of pseudomorphic ZnSe/epilayer GaAs heterointerfaces, grown by MBE, have been investigated by capacitance versus voltage (C-V) and current versus voltage (I- V) measurements. Hole accumulation and inversion were observed in ZnSe/p-GaAs interfaces and ZnSe/n-GaAs interfaces, respectively. The C-V characteristics of the Au/ZnSe/p-GaAs capacitors are nearly ideal, exhibiting an interface state density (2.5x1011cm-2) which compares favorably with the densities reported at AlGaAs/GaAs interfaces.


2014 ◽  
Vol 778-780 ◽  
pp. 619-622 ◽  
Author(s):  
Ryu Hasunuma ◽  
Masahito Nagoshi ◽  
Kikuo Yamabe

The electrical properties of SiO2/4H-SiC(0001) was characterized, and it was confirmed that the NF3 added oxidation in O2 can achieve interface with low interface state density. Optimization of NF3 added oxidation process was attempted to obtain films with both good interface properties and low leakage current. It was concluded that optimization of oxidation process should take account of obtaining proper balance among the rate of oxidation, which generates impurity carbon, the ability of carbon removal, and the rate of SiO2 etching which also affects the leakage characteristics.


Author(s):  
W. Krakow ◽  
D. A. Smith

The successful determination of the atomic structure of [110] tilt boundaries in Au stems from the investigation of microscope performance at intermediate accelerating voltages (200 and 400kV) as well as a detailed understanding of how grain boundary image features depend on dynamical diffraction processes variation with specimen and beam orientations. This success is also facilitated by improving image quality by digital image processing techniques to the point where a structure image is obtained and each atom position is represented by a resolved image feature. Figure 1 shows an example of a low angle (∼10°) Σ = 129/[110] tilt boundary in a ∼250Å Au film, taken under tilted beam brightfield imaging conditions, to illustrate the steps necessary to obtain the atomic structure configuration from the image. The original image of Fig. 1a shows the regular arrangement of strain-field images associated with the cores of ½ [10] primary dislocations which are separated by ∼15Å.


Author(s):  
J.L. Batstone ◽  
J.M. Gibson ◽  
Alice.E. White ◽  
K.T. Short

High resolution electron microscopy (HREM) is a powerful tool for the determination of interface atomic structure. With the previous generation of HREM's of point-to-point resolution (rpp) >2.5Å, imaging of semiconductors in only <110> directions was possible. Useful imaging of other important zone axes became available with the advent of high voltage, high resolution microscopes with rpp <1.8Å, leading to a study of the NiSi2 interface. More recently, it was shown that images in <100>, <111> and <112> directions are easily obtainable from Si in the new medium voltage electron microscopes. We report here the examination of the important Si/Si02 interface with the use of a JEOL 4000EX HREM with rpp <1.8Å, in a <100> orientation. This represents a true structural image of this interface.


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