On electric surface impedance

Halbritter, J.

doi:10.1007/bf01320123

Cited by 19 publications

(19 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[13][14][15] Extrapolation of plots of A/C M versus d to dϭ0 gives A/C I . The value of that is obtained using Eq.…”

Section: Introductionmentioning

confidence: 99%

Temperature dependence of the dielectric response of anodized Al–Al2O3–metal capacitors

Hickmott

2003

Journal of Applied Physics

View full text Add to dashboard Cite

Articles you may be interested inElectrode effects on the conduction mechanisms in HfO 2 -based metal-insulator-metal capacitors Effect of metal contacts on the electrical characteristics of Al 2 O 3 dielectric thin films Appl. Phys. Lett. 92, 122911 (2008); 10.1063/1.2903708Low temperature crystallization of high permittivity Ta oxide using an Nb oxide thin film for metal/insulator/metal capacitors in dynamic random access memory applicationsThe temperature dependence of capacitance, C M , and conductance, G M , of Al-Al 2 O 3 -metal capacitors with Cu, Ag, and Au electrodes has been measured between 100 and 340 K at seven frequencies between 10 kHz and 1 MHz. Al 2 O 3 films between 15 and 64 nm thick were formed by anodizing evaporated Al films in borate-glycol or borate-H 2 O electrolyte. The interface capacitance at the Al 2 O 3 -metal interface, C I , which is in series with the capacitance C D due to the Al 2 O 3 dielectric, is determined from plots of 1/C M versus insulator thickness. C I is not fixed for a given metal-insulator interface but depends on the vacuum system used to deposit the metal electrode. C I is nearly temperature independent. When C I is taken into account the dielectric constant of Al 2 O 3 determined from capacitance measurements is ϳ8.3 at 295 K. The dielectric constant does not depend on anodizing electrolyte, insulator thickness, metal electrode, deposition conditions for the metal electrode or measurement frequency. By contrast, G M of Al-Al 2 O 3 -metal capacitors depends on both the deposition conditions of the metal and on the metal. For Al-Al 2 O 3 -Cu capacitors, G M is larger for capacitors with large values of 1/C I that result when Cu is evaporated in an oil-pumped vacuum system. For Al-Al 2 O 3 -Ag capacitors, G M does not depend on the Ag deposition conditions.

show abstract

“…[13][14][15] Extrapolation of plots of A/C M versus d to dϭ0 gives A/C I . The value of that is obtained using Eq.…”

Section: Introductionmentioning

confidence: 99%

Temperature dependence of the dielectric response of anodized Al–Al2O3–metal capacitors

Hickmott

2003

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…[2,3] explains the Q drop as being due to the presence of an oxide layer with a high density of localized states which allows resonant tunneling of elec- trons between conduction levels in the metal and localized states for sufficiently high electric fields. This additional contribution to the surface resistance at high fields, R E s , has an exponential dependence to the peak surface electric field:…”

Section: Interface Tunnel Exchange Modelmentioning

confidence: 99%

“…An empirical method that is effective in reducing the Q drop is a low-temperature (100 -140 C) ''in situ'' baking of the cavity in ultrahigh vacuum. The majority of the models that try to describe the Q-drop phenomenon involve a magnetic field effect [1] while a model proposed by Halbritter [2,3] involves an electric field effect. The validity of these models can be tested by measuring a single-cell cavity in the usual TM 010 mode, used for particle acceleration, and in the TE 011 mode which has no electric field on the surface.…”

Section: Introductionmentioning

confidence: 99%

“…In particular, a thick oxide layer can be formed on the niobium surface by anodization and this should lower the onset field for the Q drop, according to the model of Refs. [2,3]. Postpurification of the niobium cavity improves the thermal conductivity of the material, which should reduce the Q drop if it would be caused by the limited heat transfer from the rf surface to the helium bath, as proposed by the so-called thermal feedback model described in Ref.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Measurement of the high-fieldQdrop in theTM010andTE011modes in a niobium cavity

Ciovati

Kneisel

2006

Phys. Rev. ST Accel. Beams

View full text Add to dashboard Cite

In the last few years superconducting radio-frequency (rf) cavities made of high-purity (residual resistivity ratio > 200) niobium achieved accelerating gradients close to the theoretical limits. An obstacle towards achieving reproducibly higher fields is represented by ''anomalous'' losses causing a sharp degradation of the cavity quality factor when the peak surface magnetic field (B p ) is above about 90 mT, in the absence of field emission. This effect, called ''Q drop'' has been measured in many laboratories with single-and multicell cavities mainly in the gigahertz range. In addition, a lowtemperature (100 -140 C) ''in situ'' baking of the cavity was found to be beneficial in reducing the Q drop. In order to gain some understanding of the nature of these losses, a single-cell cavity has been tested in the TM 010 and TE 011 modes at 2 K. The feature of the TE 011 mode is to have zero electric field on the cavity surface, so that electric field effects can be excluded as a source for the Q drop. This article will present some of the experimental results for different cavity treatments and will compare them with existing models.

show abstract

“…12 An alternative mechanism to field penetration into the metal electrode is the occurrence of interface states at the metal-insulator interface. 4,13,14 By definition, the presence of interface states results in charge exchange between the insulator and the metal when an ac voltage is applied. Such charge exchange is equivalent to an interface capacitance C I , in series with the capacitance of the dielectric, giving a relation between measured capacitance and dielectric constant that is identical to Eq.…”

Section: Introductionmentioning

confidence: 99%

Interface states at the anodized Al2O3-metal interface

Hickmott

2001

Journal of Applied Physics

View full text Add to dashboard Cite

Articles you may be interested inProperties of stacked SrTiO3/Al2O3 metal-insulator-metal capacitors J. Vac. Sci. Technol. B 31, 01A102 (2013); 10.1116/1.4766183 Impact of top electrode on electrical stress reliability of metal-insulator-metal capacitor with amorphous ZrTiO 4 film Appl. Temperature dependence of the dielectric response of anodized Al-Al 2 O 3 -metal capacitorsThe capacitance of Al-Al 2 O 3 -metal capacitors with Al 2 O 3 of different thicknesses, formed by anodizing evaporated Al films in ethylene glycol-based or H 2 O-based electrolytes to different voltages, has been measured between 10 kHz and 1 MHz for ten metal electrodes. The linear dependence of inverse capacitance on anodizing voltage, and thus on Al 2 O 3 thickness, shows that there is an interface capacitance in series with the bulk capacitance due to the dielectric properties of anodized Al 2 O 3 . The interface capacitance, C I , is not a characteristic of the Al 2 O 3 -metal combination; it depends on the vacuum deposition conditions for the metal electrodes. C I is associated with interface states at the Al 2 O 3 -metal interface, not with field penetration into metal electrodes.

show abstract

On electric surface impedance

Cited by 19 publications

References 34 publications

Temperature dependence of the dielectric response of anodized Al–Al2O3–metal capacitors

Temperature dependence of the dielectric response of anodized Al–Al2O3–metal capacitors

Measurement of the high-fieldQdrop in theTM010andTE011modes in a niobium cavity

Interface states at the anodized Al2O3-metal interface

Contact Info

Product

Resources

About