The Optical Admittance Spectroscopy of the Vanadium Donor and Acceptor Levels in Semi-Insulating 4H-SiC and 6H-SiC

2006 ◽  
Vol 527-529 ◽  
pp. 647-650
Author(s):  
Won Woo Lee ◽  
Mary Ellen Zvanut
Keyword(s):  
Thermal Relaxation ◽  
Admittance Spectroscopy ◽  
Defect Level ◽  
Defect Complexes ◽  
Donor And Acceptor ◽  
Defect Levels

The purpose of this study is to determine the vanadium defect levels in semi-insulating 4H-SiC and 6H-SiC using optical admittance spectroscopy (OAS). OAS data show several distinct peaks for the vanadium-doped SI 4H-SiC and 6H-SiC. Comparison of the data for the two polytypes suggests that peaks at 0.67 ± 0.02 eV and 0.70 ± 0.02 eV in 6H substrates and 0.75 ± 0.02 eV in 4H substrates are related to V3+/4+ levels at the cubic sites. A peak at 0.87 ± 0.02 eV in the 6H sample is assigned to the same defect level at the hexagonal site and the associated transition in 4H was observed at 0.94 ± 0.02 eV in our spectra. The donor levels are thought to be related to peaks at 1.94 ± 0.05 eV and 1.87 ± 0.05 eV in 4H and 6H samples, respectively. The differences between the values obtained from the optical admittance measurements and those reported in the literature are attributed to thermal relaxation and/or contributions from defect complexes.

Complex Defects in GaAs and GaP

1982 ◽  
Vol 14 ◽  
Author(s):  
P. J. Lin-Chung
Keyword(s):  
Electronic States ◽  
Group Iv ◽  
Experimental Results ◽  
Large Cluster ◽  
Defect Level ◽  
Defect Complexes ◽  
Densities Of States ◽  
Local Densities ◽  
Defect Levels ◽  
Gap States

ABSTRACTA study of the electronic states associated with divacancy defects and with the defect complexes involving an anion antisite with a group IV atom (Ac-IV) in GaAs and GaP is reported. The local densities of states have been determined using the large cluster recursion approach. The properties as well as the position of the gap states of the divacancy defect in GaAs are found to be consistent with the experimental results for the EL2 level. The change of the position of the defect levels of (Ac-IV) as a result of the change of bonding is analyzed. The effect of GaAs-A&As interface on the (Ac-IV) defect level is also examined.

Electronic Properties and Defect Levels Induced by n/p-Type Defect-Complexes in Ge

2021 ◽  
Author(s):  
Emmanuel Igumbor ◽  
Okikiola Olaniyan ◽  
Guy Moise Dongho-Nguimdo ◽  
Edwin Mapasha ◽  
Sohail Ahmad ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Defect Complexes ◽  
Type Defect ◽  
Defect Levels

Analysis of Deep Levels in GaAs Detector Diodes Using Impedance Spectroscopy

1993 ◽  
Vol 302 ◽  
Author(s):  
C Eiche ◽  
M Fiederle ◽  
J Weese ◽  
D Maier ◽  
D Ebling ◽  
...  
Keyword(s):  
Cross Section ◽  
Regularization Method ◽  
Capture Cross Section ◽  
Relaxation Times ◽  
Thermal Relaxation ◽  
Simulated Data ◽  
Deep Levels ◽  
Admittance Spectroscopy ◽  
Thermal Relaxation Times ◽  
Level 2

ABSTRACTImpedance or admittance spectroscopy has been shown to be a very convenient tool for the investigation of deep levels in semiconductor junctions. At constant temperature a frequency sweep is performed. After that the impedance signal is analysed by a regularization method based on Tikhonov regularization in order to obtain the thermal relaxation times of the deep levels present in the junction. The high resolution of the regularization method in comparison to conventional techniques is demonstrated using simulated data. The temperature dependence of the thermal relaxation times provides information about the properties of the deep levels such as activation energy or capture cross section. Two donor levels with activation energies dE1 =0.58 eV and dE2 =0.68 eV are observed in our detector diodes. It can be shown that the concentration of level 2 is increased after irradiation.

Correlation Between Oxygen Composition and Electrical Properties in NiO Thin Films for Resistive Random Access Memory

2010 ◽  
Vol 1250 ◽  
Author(s):  
Yusuke Nishi ◽  
Tatsuya Iwata ◽  
Tsunenobu Kimoto
Keyword(s):  
Thin Films ◽  
Random Access ◽  
Random Access Memory ◽  
Resistive Random Access Memory ◽  
Resistance Switching ◽  
Admittance Spectroscopy ◽  
Low Oxygen ◽  
Access Memory ◽  
Switching Operation ◽  
Defect Levels

AbstractAdmittance spectroscopy measurement has been performed on NiOx thin films with various oxygen compositions (x=1.0-1.2) in order to characterize localized defect levels. The activation energy and concentration of localized defect levels in NiOx films with low oxygen composition (x≤1.07) are 120-170 meV and lower than 2×1019 cm-3, respectively. From I-V measurement of the Pt/NiOx/Pt structures, samples with high oxygen composition (x≥1.10) did not show resistance switching operation, while samples with low oxygen composition (x≤1.07) did. The best oxygen composition of NiOx thin films turned out to be 1.07 in order to realize repeatable and stable resistance switching operation.

Investigation of relation between Ga concentration and defect levels of Al/Cu(In,Ga)Se2 Schottky junctions using admittance spectroscopy

2007 ◽  
Vol 515 (15) ◽  
pp. 6208-6211 ◽  
Author(s):  
T. Sakurai ◽  
N. Ishida ◽  
S. Ishizuka ◽  
K. Matsubara ◽  
K. Sakurai ◽  
...  
Keyword(s):  
Admittance Spectroscopy ◽  
Defect Levels ◽  
Schottky Junctions

Characterization of Defects in N-Type 6H-SiC Single Crystals by Optical Admittance Spectroscopy

1994 ◽  
Vol 339 ◽  
Author(s):  
A. O. Evwaraye ◽  
S. R. Smith ◽  
W. C. Mitchel
Keyword(s):  
Transition Metal ◽  
Single Crystals ◽  
Admittance Spectroscopy ◽  
Donor Atom ◽  
Deep Defect ◽  
Metal Impurities ◽  
Transition Metal Impurities ◽  
Defect Levels ◽  
Type Conduction

ABSTRACTOptical admittance spectroscopy is a technique for measuring the conductance and capacitance of a junction under illumination as a function of the wavelength of the light and the frequency of the measuring AC signal. This technique has been applied to characterize deep defect levels in 6H-SiC:N. Nitrogen is a donor atom in 6H-SiC which substitutes for carbon in three inequivalent sites (h, k1, k2). giving rise to n-type conduction. Deep defect levels attributable to transition metal impurities have also been identified in 6H-SiC:N. We have examined persistent photoconductance in this material by optical admittance spectroscopy.

Determination of donor and acceptor level energies by admittance spectroscopy in 6H SiC

1995 ◽  
Vol 29 (1-3) ◽  
pp. 122-125 ◽  
Author(s):  
C. Raynaud ◽  
C. Richier ◽  
P.N. Brounkov ◽  
F. Ducroquet ◽  
G. Guillot ◽  
...  
Keyword(s):  
Admittance Spectroscopy ◽  
Acceptor Level ◽  
Donor And Acceptor

Formation of Doping Profiles in Float Zone Silicon by Helium Implantation and Plasma Hydrogenation

2008 ◽  
Vol 1108 ◽  
Author(s):  
Reinhart Job ◽  
Franz-Josef Niedernostheide ◽  
Hans-Joachim Schulze ◽  
Holger Schulze
Keyword(s):  
Hydrogen Plasma ◽  
Subsurface Layer ◽  
Process Conditions ◽  
Defect Complexes ◽  
Float Zone ◽  
Donor And Acceptor ◽  
Subsurface Layers ◽  
Related Donor ◽  
Formation And Evolution ◽  
Doping Profiles

AbstractBy means of two-point-probe Spreading Resistance (SR) analyses, the formation and evolution of hydrogen-related and vacancy-related donor and acceptor states were studied in helium implanted and subsequently hydrogen plasma-treated n-type Float-Zone (FZ) silicon wafers. He-implantation was carried out at 3.75 MeV, applying fluences of 1×1014 cm-2 and 2×1013 cm-2. After 15-min post-implantation H-plasma exposures at substrate temperatures between 350 °C and 500 °C, distinct surplus doping profiles were observed in the subsurface layers of the treated FZ Si samples down to about 20 μm depth. Enhanced donor concentrations could be observed as well acceptor-like states, at least partially compensating for the initial n-type doping, so that even buried p-type layers can be created under appropriate process conditions. The nature of the defect complexes that were responsible for the observed doping profiles in the subsurface layer of the studied samples will be discussed.

scholarly journals Investigation of Defect Levels in Mg-Doped GaN Schottky Structures by Thermal Admittance Spectroscopy

2001 ◽  
Vol 228 (2) ◽  
pp. 385-389
Author(s):  
N.D. Nguyen ◽  
M. Germain ◽  
M. Schmeits ◽  
B. Schineller ◽  
M. Heuken
Keyword(s):  
Admittance Spectroscopy ◽  
Defect Levels ◽  
Mg Doped
Sign in / Sign up

Export Citation Format

Share Document