Electrical and optical investigation of the position of vanadium related defects in the 4H and 6H SiC bandgaps

1996 ◽  
Vol 423 ◽  
Author(s):  
J. R. Jenny ◽  
M. Skowronski ◽  
W. C. Mitchel ◽  
S. R. Smith ◽  
A. O. Evwaraye ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Hall Effect ◽  
Deep Level ◽  
Polarized Light ◽  
Conduction Band Edge ◽  
Optical Investigation ◽  
Admittance Spectroscopy ◽  
Acceptor Level ◽  
Transient Spectroscopy ◽  
Spectroscopy Optical

AbstractHall effect, deep level transient spectroscopy, optical absorption, and optical admittance spectroscopy were employed to determine the position of the vanadium acceptor and vanadiumnitrogen complex in vanadium- and nitrogen-doped 4H and 6H SiC. Hall effect results indicate that the acceptor position in 4H(6H) SiC is 0.80(0.66) eV beneath the conduction band edge. The DLTS signature of the defect in the 4H polytype showed an ionization energy of 806 meV and a capture cross section of 1.8×10−16 cmr−2 The optical absorption measurements proved that the acceptor level investigated is related to isolated vanadium, and therefore the vanadium acceptor level. Based upon DLTS and SIMS measurements, the maximum solubility of vanadium in SiC was determined to the 3×10−17 crn3. An examination of polarized light experiments indicates that vanadium also complexes with another element to form electronic(at 5000 cm−1) and vibrational absorption(at 683 cm−1) bands. While the other constituent cannot be identified, evidence suggests that nitrogen is a likely candidate. This complex introduces a deep level at Ec−0.78 eV as determined using optical admittance spectroscopy.

Electronic Properties of ZnO/Si Heterojunction Prepared by ALD.

2011 ◽  
Vol 178-179 ◽  
pp. 130-135 ◽  
Author(s):  
Vincent Quemener ◽  
Mari Alnes ◽  
Lasse Vines ◽  
Ola Nilsen ◽  
Helmer Fjellvåg ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Deep Level ◽  
Atomic Layer ◽  
Substantial Improvement ◽  
Conduction Band Edge ◽  
Energy Position ◽  
Layer Deposition ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Transient Spectroscopy

ZnO/n-Si and ZnO/p-Si heterostructures were prepared by Atomic layer deposition (ALD) and the electronic properties have been investigated by Current-Voltage (I-V), Capacitance-Voltage (C-V) and Deep level transient spectroscopy (DLTS) measurements. DLTS measurements show two dominants electron traps at the interface of the ZnO/n-Si junction with energy position at 0.07 eV and 0.15 eV below the conduction band edge, labelled E(0.07) and E(0.15), respectively, and no electrically active defects at the interface of the ZnO/p-Si junction. E(0.07) is reduced by annealing up to 400°C while E(0.15) is created at 500°C. The best heterostructure is found after heat treatment at 400°C with a substantial improvement of the current rectification for ZnO/n-Si and the formation of Ohmic contact on ZnO/p-Si. A reduction of the interface defects correlates with an improvement of the crystal structure of the ZnO film with a preferred orientation along the c-axis.

Deep level transient spectroscopic and Hall effect investigation of the position of the vanadium acceptor level in 4H and 6H SiC

1996 ◽  
Vol 68 (14) ◽  
pp. 1963-1965 ◽  
Author(s):  
J. R. Jenny ◽  
J. Skowronski ◽  
W. C. Mitchel ◽  
H. M. Hobgood ◽  
R. C. Glass ◽  
...  
Keyword(s):  
Hall Effect ◽  
Deep Level ◽  
Acceptor Level

Capacitance Spectroscopy Study of High Energy Electron Irradiated and Annealed 4H-SiC

2005 ◽  
Vol 483-485 ◽  
pp. 365-368 ◽  
Author(s):  
Giovanni Alfieri ◽  
Edouard V. Monakhov ◽  
Margareta K. Linnarsson ◽  
Bengt Gunnar Svensson
Keyword(s):  
Deep Level ◽  
Chemical Vapor ◽  
High Energy ◽  
Conduction Band Edge ◽  
Energy Band Gap ◽  
Annealing Step ◽  
Radiation Induced ◽  
Transient Spectroscopy ◽  
Induced Defects ◽  
Thermal Stability Of

Deep level transient spectroscopy (DLTS) was employed to investigate the annealing behaviour and thermal stability of radiation induced defects in nitrogen doped 4H-SiC epitaxial layers, grown by chemical vapor deposition (CVD). The epilayers have been irradiated with 15 MeV electrons and an isochronal annealing series has been carried out. The measurements have been performed after each annealing step and six electron traps located in the energy band gap range of 0.42-1.6 eV below the conduction band edge (Ec) have been detected.

Transformation of Gold in N-Type Silicon from a New Deep Level to the Gold Acceptor Level

1992 ◽  
Vol 262 ◽  
Author(s):  
Einar Ö. SveinbjöRnsson ◽  
Olof Engström
Keyword(s):  
Deep Level ◽  
Depth Profiling ◽  
Sample Surface ◽  
Acceptor Level ◽  
Electron Capture Cross Section ◽  
Acceptor Concentration ◽  
Type Silicon ◽  
Float Zone ◽  
Transient Spectroscopy ◽  
Diffusion Of Hydrogen

ABSTRACTUsing deep level transient spectroscopy (DLTS) on gold-doped n-type Czochralski (CZ) and float zone (FZ) silicon we observe a new gold-related acceptor level (G) with an activation energy σn= 0.19 eV and an electron capture cross section On = 1–10-17 cm2. The center anneals out at a temperature of 250°C, simultaneously as the gold acceptor concentration increases. Annealing at temperatures below 250°C does not reverse this process. However, etching a few microns off the sample surface using HF:HNO3 based etch reforms the G center and the gold acceptor concentration decreases accordingly. From DLTS depth-profiling we determine that the new center is only found at depths less than 5 μm, and in the same region we observe neutralization of phosphorus dopants and a reduction in the gold acceptor concentration.We propose that in-diffusion of hydrogen during the etching process is responsible for the three observed transitions, i.e. neutralization of both phosphorus donors and gold acceptors and formation of the G center. We suggest that there are (at least) two possible Au-H complex centers, one which is electrically inactive and another which gives rise to an acceptor level (ΔE = 0.19 eV) in the bandgap of n-type silicon. The electrically active center anneals out at 250°C while the electrically inactive one is more stable and has been observed earlier in remote plasma hydrogenation experiments performed at 150–350°C.

Deep Level near EC – 0.55 eV in Undoped 4H-SiC Substrates

2006 ◽  
Vol 527-529 ◽  
pp. 505-508
Author(s):  
W.C. Mitchel ◽  
William D. Mitchell ◽  
S.R. Smith ◽  
G.R. Landis ◽  
A.O. Evwaraye ◽  
...  
Keyword(s):  
Hall Effect ◽  
Deep Level ◽  
Activation Energies ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Admittance Spectroscopy ◽  
Temperature Dependent ◽  
Thermally Stimulated Current ◽  
Commercial Grade ◽  
Transport Technique

A variety of 4H-SiC samples from undoped crystals grown by the physical vapor transport technique have been studied by temperature dependent Hall effect, optical and thermal admittance spectroscopy and thermally stimulated current. In most samples studied the activation energies were in the range 0.9 - 1.6 eV expected for commercial grade HPSI 4H-SiC. However, in several samples from developmental crystals a previously unreported deep level at EC-0.55 ± 0.01 eV was observed. Thermal admittance spectroscopy detected one level with an energy of about 0.53 eV while optical admittance spectroscopy measurements resolved two levels at 0.56 and 0.64 eV. Thermally stimulated current measurements made to study compensated levels in the material detected several peaks at energies in the range 0.2 to 0.6 eV.

Laplace Transform Deep Level Transient Spectroscopy Study of the EH6/7 Center

2013 ◽  
Vol 740-742 ◽  
pp. 645-648 ◽  
Author(s):  
Giovanni Alfieri ◽  
Tsunenobu Kimoto
Keyword(s):  
Laplace Transform ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Dose Dependence ◽  
Conduction Band Edge ◽  
Emission Rates ◽  
Energy Position ◽  
Low Energy Electron ◽  
Transient Spectroscopy ◽  
Electric Filed

We employed Laplace transform deep level transient spectroscopy (LDLTS) for the resolution of the EH6/7 center in n-type 4H-SiC epilayers. Our results suggest that this technique is effective in separating the emission rates of the EH6 and EH7 levels. From the Arrhenius dependence of the emission rates we could estimate the energy position of EH6 and EH7 as 1.39 and 1.49 eV below the minimum of the conduction band edge, respectively. Generation of of EH6 and EH7 centers by low-energy electron irradiation (dose dependence) was also investigated. At last, a double pulse Laplace DLTS is performed in order to show the electric filed dependence of the emission rates of EH6 and EH7.

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