Study of Deep Levels by Admittance Spectroscopy in High Resistivity P-Type 6H-SiC Single Crystals

1995 ◽  
Vol 378 ◽  
Author(s):  
A. O. Evwaraye ◽  
S. R. Smith ◽  
W. C. Mitchel
Keyword(s):  
Single Crystals ◽  
Deep Levels ◽  
High Resistivity ◽  
Admittance Spectroscopy ◽  
Donor Level ◽  
Decay Kinetics ◽  
Exponential Form ◽  
Conductance Peak ◽  
P Type ◽  
Kinetics Of

AbstractDeep levels in high resistivity p-type 6H-SiC has been studied using optical admittance spectroscopy ( OAS ). Besides the conductance peak due to the band to band transitions, there are three conductance peaks in the spectra of most of the samples. The conductance peak due to the vanadium donor (0/+) level at EV+ 1.55 eV is identified. The persistent photoconductance (PPC) at this defect was also studied. The decay kinetics of the PPC follow the stretched exponential form. The potential barrier against recapture of carriers was determined to be 220 meV for the vanadium donor level.

Photoluminescence & decay kinetics of Cs4PbCl6 single crystals

1992 ◽  
Vol 84 (12) ◽  
pp. 1089-1092 ◽  
Author(s):  
M. Nikl ◽  
E. Mihokova ◽  
K. Nitsch
Keyword(s):  
Single Crystals ◽  
Decay Kinetics ◽  
Photoluminescence Decay ◽  
Kinetics Of

Implant Isolation Mechanisms in GaAs, AlGaAs, InP and InGaAs

1988 ◽  
Vol 144 ◽  
Author(s):  
S. J. Pearton ◽  
C. R. Abernathy ◽  
W. S. Hobson ◽  
A. E. Von Neida
Keyword(s):  
Target Material ◽  
Interesting Case ◽  
Deep Levels ◽  
High Resistivity ◽  
Doping Density ◽  
Deep Acceptor ◽  
P Type ◽  
Ion Species ◽  
Isolation Mechanisms ◽  
Stable Material

ABSTRACTWe have investigated the thermal stability of high resistivity regions introduced by ion bombardment of GaAs, AlGaAs, InP and InGaAs. For low doses in which the ion species density is below that of the doping density in the target material, we obtain the usual damage-related compensation in which deep levels created by the bombardment trap the charge carriers. By this method one creates material with resistivities around 108 Ω/□ (n- or p-type GaAs and AlGaAs, p-type InP), around 106 Ω/□ (n-type InP) or around 105 Ω/□ (n-type InGaAs or p-type InGaAs), with a return of the initial resistivity after elevated temperature annealing (∼600°C for GaAs and AIGaAs, ∼500°C for InP and InGaAs). The more interesting case is the use of higher dose implants of species which create chemical deep levels. This occurs for O in n-type AlGaAs where O creates a deep acceptor (Ec-0.49 eV), and Fe in n-type InP and InGaAs, where it is also a deep acceptor. When the concentration of these species exceeds the doping density in the material, the bombarded regions retain their high resistivity even after high temperature annealing (> 1000°C for GaAs and AIGaAs, >850°C for InP and InGaAs). The case of O in GaAs appears to represent a third mechanism; it creates thermally stable material only in the case of Be-doped GaAs, suggesting an ion-pairing reaction.

Shallow and Deep Levels in Al+-Implanted p-Type 4H-SiC Measured by Thermal Admittance Spectroscopy

2015 ◽  
Vol 821-823 ◽  
pp. 403-406 ◽  
Author(s):  
Koutarou Kawahara ◽  
Hiroshi Watanabe ◽  
Naruhisa Miura ◽  
Shuhei Nakata ◽  
Satoshi Yamakawa
Keyword(s):  
Cross Section ◽  
Ionization Energy ◽  
Capture Cross Section ◽  
Deep Levels ◽  
Admittance Spectroscopy ◽  
Capture Cross ◽  
Shallow Acceptor ◽  
Wide Range ◽  
Emission Time ◽  
P Type

Shallow and deep levels in SiC significantly affect dynamic characteristics of SiC devices; larger ionization energy and/or a smaller capture cross-section of levels in the SiC bandgap lead to a larger emission time constant and slower response of carriers. Nevertheless, knowledge about those levels is very limited. In this study, we clarified the ionization energy and the capture cross section of the Al shallow acceptor in 4H-SiC in a wide range of doping concentration by preparing appropriate samples and measuring them by thermal admittance spectroscopy. Furthermore, high densities of deep levels were discovered in Al+-implanted samples, which can degrade 4H-SiC device performance without any care.

Photoluminescence and decay kinetics of CsPbCl3 single crystals

1994 ◽  
Vol 220 (1-2) ◽  
pp. 14-18 ◽  
Author(s):  
M. Nikl ◽  
E. Mihokova ◽  
K. Nitsch ◽  
K. Polak ◽  
M. Rodova ◽  
...  
Keyword(s):  
Single Crystals ◽  
Decay Kinetics ◽  
Kinetics Of

Silicon Detectors Highly Compensated by Neutron Induced Deep Levels for Low Energy X-RAY Detection

1993 ◽  
Vol 302 ◽  
Author(s):  
Zheng Li ◽  
H. W. Kraner
Keyword(s):  
Neutron Radiation ◽  
Low Noise ◽  
Deep Levels ◽  
High Resistivity ◽  
Silicon Detectors ◽  
Obvious Effect ◽  
X Ray ◽  
Shaping Time ◽  
Resistive Feedback ◽  
P Type

ABSTRACTFast neutron radiation damage in silicon results in defect levels which are predominantly acceptor-like at low fluences and may be used to compensate high resistivity ntype material to create very high effective resisitivity material. Compensated material to the order of Neff below 1011/cm3 enables depletion of diode thicknesses ≥ 1mm at reasonable biases (<100V), yielding diodes of reasonable area and capacitance<1 pF which are suitable for low noise applications such as X-ray spectrometry. Although exposure to fluences of this order will greatly increase the generation current and require cooling, most high resolution X-ray spectrometry systems are routinely operated at reduced temperature to achieve low noise operation of the front end electronics. Silicon p+ /n− /n+ implanted devices (area ≤0.25 cm2) made on high resistivity FZ silicon have been irradiated by 1 MeV neutrons to fluences of a few times 1012 n/cm2. Thick n− substrates (d=630 μm and 1000 μm) were used to achieve detector capacitances εεo/d in the range of 1 pF. After a neutron fluence of ϕn=2.9×1012 n/cm2, the total depletion of a p+/n−/n+ detector, 1040 μm thick and an area of 0.1 cm2, is reached at about V=50 Volts, with a Cd of 1 pF and a neutron induced leakage current of about 300 nA at room temperature. A total depletion of an 680 μm thick detector was reached after the fluence of 2-5×1012 n/cm2 at a voltage of 20 volts, and the capacitance of a 0.25 cm2 diode is 4.5 pF The resistivities of the compensated detector substrates are in the range of 100 K Ω-cm, and are not inverted to “p” type. The trapping of collected charge by neutron induced deep levels is modeled and simulated, and is found to be less than a few percent; with no obvious effect on peak shape. Using a resistive feedback preamplifier of modest noise contribution (225 eV), resolution of the Mn K∝ X-ray was 255 eV (FWHM) with 3 μsec shaping time constants. Other effects of uncollected charge will be discussed and comparisons between this type of detectors and Li-drift silicon detectors will be made.

Thermoliiminescence Emission and Decay Kinetics of NaCl:SnCl2 Single Crystals

1984 ◽  
Vol 81 (2) ◽  
pp. 533-540 ◽  
Author(s):  
B. S. Acharya ◽  
M. L. Mukherjee ◽  
C. M. Sunta ◽  
S. P. Kathuria
Keyword(s):  
Single Crystals ◽  
Decay Kinetics ◽  
Kinetics Of

Influence of Tl + concentration on emission and decay kinetics of CsI : Tl + single crystals

1994 ◽  
Vol 60-61 ◽  
pp. 527-530 ◽  
Author(s):  
G.P. Pazzi ◽  
M. Nikl ◽  
M. Bacci ◽  
E. Mihokova ◽  
J. Hlinka ◽  
...  
Keyword(s):  
Single Crystals ◽  
Decay Kinetics ◽  
Kinetics Of

The Effect of Annealing on High-resistivity and Semi-insulating 4H-SiC

2002 ◽  
Vol 742 ◽  
Author(s):  
S. R. Smith ◽  
A. O. Evwaraye ◽  
W. C. Mitchel
Keyword(s):  
Transition Metal ◽  
Thermal Oxidation ◽  
Thermal Annealing ◽  
Deep Levels ◽  
High Resistivity ◽  
Admittance Spectroscopy ◽  
Metal Impurities ◽  
Transition Metal Impurities ◽  
Before And After

ABSTRACTWe have examined specimens of high-resistivity, and semi-insulating, 4H-SiC before and after thermal annealing at 1600 °C, using Optical Admittance Spectroscopy. We have found enhanced ultraviolet response in most specimens. Enhanced activation of previously undetected V impurities has also been observed. Peaks believed to be attributable to complex V-related defects were greatly reduced by annealing. The annealing was in addition to a thermal oxidation at 1150 °C for 4 hours. The purpose of the oxidation was to remove surface-related deep levels known to be present in polished SiC. Transition metal impurities in these bulk specimens were quantified by SIMS. In specimens where Ti was not detected by SIMS, no further activation of Ti centers was detected by Optical Admittance Spectroscopy.

scholarly journals EVOLUTION OF A DISLOCATION STRUCTURE DURING THE GROWTH SILICON SINGLE CRYSTALS OF n- AND p-TYPE

2020 ◽  
pp. 44-50
Author(s):  
N.A. Azarenkov ◽  
V.E. Semenenko ◽  
N.G. Stervoyedov
Keyword(s):  
Phase Transformation ◽  
Single Crystals ◽  
Dislocation Structure ◽  
Semiconductor Devices ◽  
Screw Dislocations ◽  
Linear Defects ◽  
The Stability ◽  
P Type ◽  
Kinetics Of ◽  
Concentration Of Impurities

The kinetics of the formation of perfect n- and p-type silicon single crystals is considered. The peculiarity of the formation of point and linear defects in the process of a controlled phase transformation of a liquid-solid is established. The effect of supersaturation by vacancies of the direction of predominant growth and concentration of impurities on the formation and removal of edge and screw dislocations is determined. The effect of linear defects on the scattering and recombination of mobile current carriers is revealed. The possibilities of increasing the stability and efficiency of silicon semiconductor devices are discussed.

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