Identification of Deep‐Level States in Electronic Materials by Optically Stimulated Deep Level Impedance Spectroscopy

AbstractThe Au/Pd/Ti–SiO2-(n) GaAs properties have been analyzed via impedance spectroscopy (IS), as well as DLTS and ICTS, to identify the origin of electron processes responsible for existence of constant phase elements (CPE) in an equivalent circuits of that structure. We showed that CPEs connected in series with resistance represents the electron processes associated with deep levels in GaAs and/or interface states at SiO2-(n) GaAs interface, depending on the value of n of CPE parameter. CPE with n close to 1 characterize the electron processes associated with EL2 deep level, and CPE with n = 0.5–0.65 the complex electron processes associated with EL3 deep level and interface states together. We stated that constant phase elements in equivalent circuits of MIS-GaAs structures with large frequency dispersion of electrical characteristics can be the result of more than one electron process.

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Dielectric Response of ZnTe–Ti/Al Schottky Junctions with CdTe Quantum Dots Studied by Impedance Spectroscopy

Crystals ◽

10.3390/cryst10030170 ◽

2020 ◽

Vol 10 (3) ◽

pp. 170

Author(s):

Eunika Zielony ◽

Ewa Płaczek-Popko ◽

Grzegorz Karczewski

Keyword(s):

Activation Energy ◽

Quantum Dots ◽

Impedance Spectroscopy ◽

Quantum Dot ◽

Electric Modulus ◽

Deep Level ◽

Reference Sample ◽

Relaxation Processes ◽

Zero Bias ◽

Schottky Junctions

The electrical properties of ZnTe–Ti/Al Schottky junctions were investigated by the impedance spectroscopy (IS) method. Current-voltage (I-V) and capacitance-voltage (C-V) measurements were also performed. The studied samples were the CdTe quantum dot structures embedded in ZnTe matrix and a reference ZnTe sample without quantum dots. C-V characteristics confirmed the presence of quantum dots (QDs) in the structures. Electric modulus and impedance data were analyzed. IS studies proved that long-range conductivity governs the relaxation processes in the junctions. For both samples, the data were fitted with a simple RC circuit composed of a depletion layer capacitance in parallel with bulk resistance and a series resistance of contacts. The activation energy of the relaxation process observed for the reference sample obtained from the Arrhenius plot of the resistance, imaginary impedance, and electric modulus equals 0.4 eV at zero bias. For the quantum dot sample, the value of activation energy determined with the help of the same methods equals 0.2 eV. In conclusion, it was assumed that the relaxation processes for the reference sample are attributed to the trap present in ZnTe host material, whereas those observed for the QD structure are assigned to the deep level associated with defects located close to the QDs created during their growth.

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A Mathematical Model for the Influence of Deep‐Level Electronic States on Photoelectrochemical Impedance Spectroscopy: II . Assessment of Characterization Methods Based on Mott‐Schottky Theory

Journal of The Electrochemical Society ◽

10.1149/1.2069156 ◽

1992 ◽

Vol 139 (1) ◽

pp. 127-131 ◽

Cited By ~ 12

Author(s):

D. Bivings Bonham ◽

Mark E. Orazem

Keyword(s):

Mathematical Model ◽

Impedance Spectroscopy ◽

Deep Level ◽

Electronic States ◽

Characterization Methods

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Liquid junctions for characterization of electronic materials. IV. Impedance spectroscopy of reactive ion‐etched Si

Journal of Applied Physics ◽

10.1063/1.344310 ◽

1989 ◽

Vol 66 (5) ◽

pp. 2148-2155 ◽

Cited By ~ 4

Author(s):

M. C. A. Fantini ◽

Wu‐Mian Shen ◽

Micha Tomkiewicz ◽

J. P. Gambino

Keyword(s):

Impedance Spectroscopy ◽

Electronic Materials

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Applications of SIMS to electronic materials and devices

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100133047 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1682-1683

Author(s):

S.F. Corcoran

Keyword(s):

Depth Distribution ◽

Secondary Ion Mass Spectrometry ◽

Semiconductor Device ◽

Electronic Materials ◽

Profile Analysis ◽

Semiconductor Industry ◽

Small Diameter ◽

Depth Resolution ◽

Detection Sensitivity

Over the past decade secondary ion mass spectrometry (SIMS) has played an increasingly important role in the characterization of electronic materials and devices. The ability of SIMS to provide part per million detection sensitivity for most elements while maintaining excellent depth resolution has made this technique indispensable in the semiconductor industry. Today SIMS is used extensively in the characterization of dopant profiles, thin film analysis, and trace analysis in bulk materials. The SIMS technique also lends itself to 2-D and 3-D imaging via either the use of stigmatic ion optics or small diameter primary beams.By far the most common application of SIMS is the determination of the depth distribution of dopants (B, As, P) intentionally introduced into semiconductor materials via ion implantation or epitaxial growth. Such measurements are critical since the dopant concentration and depth distribution can seriously affect the performance of a semiconductor device. In a typical depth profile analysis, keV ion sputtering is used to remove successive layers the sample.

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