Application of zero-temperature-gradient zero-bias thermally stimulated current spectroscopy to ultrathin high-dielectric-constant insulator film characterization

Lau, W. S.; Wong, K. F.; Han, Taejoon; Sandler, N. P.

doi:10.1063/1.2199590

Cited by 11 publications

(10 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition to thermopolarization current, the current may originate from the small voltage burden on the picoammeter (about 300 µV in case of device used in our experiments) or from a temperature gradient across the sample (potential difference of Seebeck effect). 66 Let us assume that the current originates from one of these three sources. For a sample with a perfect centric symmetry, the two orientations of a sample, "up" and "down", should be equivalent and the response to either the voltage or the temperature gradient should be the same, regardless of the orientation of the sample.…”

Section: Pyroelectric Propertiesmentioning

confidence: 99%

Symmetry breaking in hexagonal and cubic polymorphs of BaTiO3

Hashemizadeh

Biancoli

Damjanović

2016

Journal of Applied Physics

View full text Add to dashboard Cite

BaTiO3 appears in cubic and hexagonal variants, both of which are centrosymmetric. Samples of cubic BaTiO3 are known to exhibit breaking of the centric symmetry locally and globally. It has been proposed that the local symmetry breaking originates in polar regions, the precursors of the ferroelectric phase. Origins of the macroscopic symmetry breaking, which are not well understood, have been previously tentatively correlated with inhomogeneities in the samples, such as strain gradients that may align or redistribute objects such as charged point defects or polar regions making material macroscopically polar. No such data are available for BaTiO3 with hexagonal symmetry. We compare dielectric, elastic, and pyroelectric properties of the two materials in polycrystalline form. In contrast to cubic BaTiO3, hexagonal BaTiO3 does not exhibit macroscopic pyroelectric response at room temperature. This is consistent with apparent absence of polar regions in the hexagonal material and the fact that in hexagonal BaTiO3 strain rather then polarization is the order parameter for the phase transition into ferroelectric-ferroelastic phase. The thermally stimulated currents measured in hexagonal and cubic BaTiO3, however, show that both materials exhibit noncentric macroscopic symmetry. This result supports the idea that extrinsic factors such as strain gradients, which are apparently common for both materials, may break the macroscopic symmetry, which may then lead to alignment and redistribution of polar regions or charged defects.Comment: accepted in Journal of Applied Physic

show abstract

Section: Pyroelectric Propertiesmentioning

confidence: 99%

Symmetry breaking in hexagonal and cubic polymorphs of BaTiO3

Hashemizadeh

Biancoli

Damjanović

2016

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…[17][18][19][20][21][22] The precursor used was tantalum ethoxide with the chemical formula of Ta(OC 2 H 5 ) 5 . As deposited Ta 2 O 5 film is amorphous and very leaky.…”

Section: Methodsmentioning

confidence: 99%

“…[17][18][19][20][21][22] Conventional TSC technique suffers from a serious parasitic current problem because of the need to apply a bias voltage to the sample. The purpose of "zero bias" is to solve this parasitic current problem.…”

Section: Methodsmentioning

confidence: 99%

Mechanisms of Difficulty to Correlate the Leakage Current of High-k Capacitor Structures with Defect States Detected Spectroscopically by the Thermally Stimulated Current Technique

Lau

2012

J. Electrochem. Soc.

View full text Add to dashboard Cite

Historically, it has been difficult to correlate the leakage current of capacitor structures involving high-k dielectric materials and defect states detected spectroscopically by the thermally stimulated current (TSC) technique. Four mechanisms are proposed and solutions are explained with tantalum oxide as an example. One of the mechanisms is the limitation of the TSC technique itself because of the presence of a parasitic current due to the bias voltage used. This can be solved by migrating to more advanced versions of TSC like zero-bias TSC or zero-temperature-gradient zero-bias TSC. In addition, another possible mechanism is that some defect states may have an electron repulsive energy barrier. Furthermore, another possible mechanism is that the leakage current may be insensitive to the presence of defect states under some situations; a unified Schottky-Poole-Frenkel model is proposed by the author to explain such a situation. Finally, another mechanism is due to the non-uniform distribution of defect states. Sometimes, this can be solved by using a 2-zone model proposed by the author.

show abstract

“…Charge relaxation during the heating scan of the ZB-TSC can be discussed [9] in terms of motion of the zero electric-field planes (ZFP) along the sample depth. Details on the ZB-TSC technique applied on different semiconductor materials are reported in [10,11].…”

Section: Experimental Techniquesmentioning

confidence: 99%

TSC studies on n- and p-type MCZ Si pad detectors irradiated with neutrons up to 1016n/cm2

Bruzzi¹

2010

Proceedings of 9th International Conference on Large Scale Applications and Radiation Hardness of Semiconductor Detectors — PoS

View full text Add to dashboard Cite

We report on the investigation of the radiation damage induced by neutron irradiation on both nand p-type Magnetic Czochralski silicon pad detectors by the Thermally Stimulated Currents (TSC) technique. Detectors have been irradiated with fast neutrons in the range 10 14-10 16 n/cm 2. Priming conditions have been studied in detail in order to investigate the residual electric field due to frozen charged traps after the priming step and its influence on the TSC emission. Zero bias TSC measurements have also been performed as an additional tool to study the defects distribution and the residual electric field. The electric field distribution inside the sample and its effect on the TSC emission are qualitatively explained by a band diagrams description.

show abstract

Application of zero-temperature-gradient zero-bias thermally stimulated current spectroscopy to ultrathin high-dielectric-constant insulator film characterization

Cited by 11 publications

References 16 publications

Symmetry breaking in hexagonal and cubic polymorphs of BaTiO3

Symmetry breaking in hexagonal and cubic polymorphs of BaTiO3

Mechanisms of Difficulty to Correlate the Leakage Current of High-k Capacitor Structures with Defect States Detected Spectroscopically by the Thermally Stimulated Current Technique

TSC studies on n- and p-type MCZ Si pad detectors irradiated with neutrons up to 1016n/cm2

Contact Info

Product

Resources

About