Activation energies in diamond films evaluated using admittance spectroscopy and resistivity measurements

2007 ◽  
Vol 101 (3) ◽  
pp. 033714 ◽  
Author(s):  
Adenilson J. Chiquito ◽  
Olívia M. Berengue ◽  
Edgar Diagonel ◽  
José C. Galzerani ◽  
João R. Moro
Keyword(s):  
Diamond Films ◽  
Activation Energies ◽  
Admittance Spectroscopy ◽  
Resistivity Measurements

Impurity Conduction in n-Type 4H-SIC

1996 ◽  
Vol 423 ◽  
Author(s):  
A. O. Evwaraye ◽  
S. R. Smith ◽  
W. C. Mitchel ◽  
M. D. Roth
Keyword(s):  
Activation Energies ◽  
Hopping Conduction ◽  
Admittance Spectroscopy ◽  
Temperature Dependent ◽  
Resistivity Measurements ◽  
Nitrogen Levels ◽  
Impurity Conduction ◽  
Measured Activation ◽  
Temperature Dependent Resistivity ◽  
Type Sample

AbstractImpurity conduction (or hopping conduction) has been observed in the more heavily n-type 4H-SiC samples by both temperature dependent resistivity measurements and thermal admittance spectroscopy. The measured activation energies ɛ 3 for hopping were 4–5 meV and 2.3–3.0 meV respectively. No evidence of hopping conduction was seen by either method in the sample where ND-NA < 1018 cm-3. The thermal admittance spectrum of the lightly n-type sample showed the two nitrogen levels at 53 and 100 meV.

scholarly journals Effect of Nitrogen on the Growth of (100)-, (110)-, and (111)-Oriented Diamond Films

2020 ◽  
Vol 11 (1) ◽  
pp. 126
Author(s):  
Jen-Chuan Tung ◽  
Tsung-Che Li ◽  
Yen-Jui Teseng ◽  
Po-Liang Liu
Keyword(s):  
Growth Mechanism ◽  
Density Functional ◽  
Film Growth ◽  
Hydrogen Abstraction ◽  
Diamond Films ◽  
Activation Energies ◽  
Diamond Surface ◽  
Nitrogen Doped ◽  
Nitrogen Substitution ◽  
Diamond Film Growth

The aim of this research is the study of hydrogen abstraction reactions and methyl adsorption reactions on the surfaces of (100), (110), and (111) oriented nitrogen-doped diamond through first-principles density-functional calculations. The three steps of the growth mechanism for diamond thin films are hydrogen abstraction from the diamond surface, methyl adsorption on the diamond surface, and hydrogen abstraction from the methylated diamond surface. The activation energies for hydrogen abstraction from the surface of nitrogen-undoped and nitrogen-doped diamond (111) films were −0.64 and −2.95 eV, respectively. The results revealed that nitrogen substitution was beneficial for hydrogen abstraction and the subsequent adsorption of methyl molecules on the diamond (111) surface. The adsorption energy for methyl molecules on the diamond surface was generated during the growth of (100)-, (110)-, and (111)-oriented diamond films. Compared with nitrogen-doped diamond (100) films, adsorption energies for methyl molecule adsorption were by 0.14 and 0.69 eV higher for diamond (111) and (110) films, respectively. Moreover, compared with methylated diamond (100), the activation energies for hydrogen abstraction were by 0.36 and 1.25 eV higher from the surfaces of diamond (111) and (110), respectively. Growth mechanism simulations confirmed that nitrogen-doped diamond (100) films were preferred, which was in agreement with the experimental and theoretical observations of diamond film growth.

Thermal activation energies of Mg in GaN:Mg measured by the Hall effect and admittance spectroscopy

2000 ◽  
Vol 88 (5) ◽  
pp. 2564-2569 ◽  
Author(s):  
D. J. Kim ◽  
D. Y. Ryu ◽  
N. A. Bojarczuk ◽  
J. Karasinski ◽  
S. Guha ◽  
...  
Keyword(s):  
Hall Effect ◽  
Thermal Activation ◽  
Activation Energies ◽  
Admittance Spectroscopy

Deep Trap Characterization In GaN Using Thermal And Optical Admittance Spectroscopy

1997 ◽  
Vol 482 ◽  
Author(s):  
A. Krtschil ◽  
H. Witte ◽  
M. Lisker ◽  
J. Christen ◽  
U. Birkle ◽  
...  
Keyword(s):  
Deep Level ◽  
Chemical Vapor ◽  
High Sensitivity ◽  
Deep Trap ◽  
Infrared Region ◽  
Activation Energies ◽  
High Resistivity ◽  
Admittance Spectroscopy ◽  
Thermal Transitions ◽  
Interface Defect

AbstractDeep defect levels and the optical as well as thermal transitions of carriers from the levels into the corresponding bands were analyzed using Thermal and Optical Admittance Spectroscopy. High resistivity GaN-layers grown by MBE and heterostructures consisting of n-type GaN-layers grown with Low Pressure Chemical Vapor Deposition on 6H-SiC substrates are investigated. In the MBE-grown GaN layers we determine deep electron traps with thermal activation energies of EA=(0.45±0.04)eV and EA=(0.65±0.03)eV. Furthermore, three different kinds of optical transitions were distinguished by Optical Admittance Spectroscopy: near band gap transitions including the transition between the valence band and a shallow donor 50meV below the conduction band, a peak at 2.1eV associated with the yellow photoluminescence band and various deep level-band transitions in the infrared region.The high sensitivity of the TAS to interface defect states was used to investigate GaN/SiC heterostructures. We found an interface defect state at 70 … 90meV. Furthermore, one level was obtained originating from the epitaxial GaN-layer having an activation energy of 63±3meV. A defect distribution was identified in the p-type SiC-substrate with activation energies between 160meV and 180meV.

Impurity Conduction in Silicon Carbide

2007 ◽  
Vol 556-557 ◽  
pp. 367-370 ◽  
Author(s):  
Michael Krieger ◽  
Kurt Semmelroth ◽  
Heiko B. Weber ◽  
Gerhard Pensl ◽  
Martin Rambach ◽  
...  
Keyword(s):  
Activation Energy ◽  
Low Temperature ◽  
Low Temperatures ◽  
Nearest Neighbor ◽  
Arrhenius Plot ◽  
Schottky Contacts ◽  
Steep Slope ◽  
Admittance Spectroscopy ◽  
Resistivity Measurements ◽  
Impurity Conduction

We report on admittance spectroscopy (AS) investigations taken on aluminum (Al)- doped 6H-SiC crystals at low temperatures. Admittance spectra taken on Schottky contacts of highly doped samples (NA ≥ 7.2×1017 cm-3) reveal two series of conductance peaks, which cause two different slopes of the Arrhenius plot. The steep slope is attributed to the Al acceptor, while the flatter one - obtained from the low temperature peaks - is attributed to the activation energy ε3 of nearest neighbor hopping. We propose a model, which explains the unexpected sharpness of the low temperature conductance peaks and the disappearance of these peaks for low acceptor concentrations. The model is verified by simulation, and the AS results are compared with corresponding results obtained from resistivity measurements taken on 4H- and the identical 6HSiC samples.

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.

MEASUREMENT OF ELECTRICAL ACTIVATION ENERGY IN BLACK CVD DIAMOND USING IMPEDANCE SPECTROSCOPY

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4487-4492
Author(s):  
HAITAO YE ◽  
OLIVER A. WILLIAMS ◽  
RICHARD B. JACKMAN
Keyword(s):  
Activation Energy ◽  
Deep Level ◽  
Diamond Films ◽  
Activation Energies ◽  
Electrical Activation ◽  
Capacitance Measurement ◽  
Free Standing ◽  
Low Frequencies ◽  
Wide Range ◽  
Diamond Grain

Dc current-voltage (I-V) measurement, Hall measurement, Deep-level transient-spectroscopy (DLTS), and flatband capacitance measurement have been used to investigate electrical activation energies in diamond. However, the deviations still exist in the published activation energies obtained by these methods. In this paper, we report the first measurement of impedance on free-standing diamond films from 0.1Hz to 10MHz up to 300°C. A wide range of CVD materials have been investigated, but here we concentrate on 'black' diamond grown by MWPECVD. The Cole-Cole (Z′ via Z″) plots are well fitted to a RC parallel circuit model and the equivalent Resistance and Capacitance for the diamond films have been estimated using the Zview curve fitting. The results show only one single semicircle response at each temperature measured. It was found that the resistance decreases from 62 MΩ at room temperature to 4 KΩ at 300°C, with an activation energy around 0.15eV. The equivalent capacitance is maintained at the level of 102 pF up to 300°C suggesting that the diamond grain boundaries are dominating the conduction. At 400°C, the impedance at low frequencies shows a linear tail, which can be explained that the AC polarization of diamond/Au interface occurs.

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