Temperature and thickness dependence of the resistivity of thin polycrystalline aluminium, cobalt, nickel, palladium, silver and gold films

Vries, J.W.C. de

doi:10.1016/0040-6090(88)90478-6

Cited by 141 publications

(94 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The general consensus is that this low conductivity is due to the scattering from grain boundaries. 9,10 For Al and Au, the conductivity measured with the dc thin film experiments at 80 K is two to four times greater than the corresponding conductivity measured with terahertz. For Ag, the conductivity measured by the dc thin film experiments at 80 K is only 10% greater than the corresponding terahertz measurements.…”

Section: ͑2͒mentioning

confidence: 99%

See 1 more Smart Citation

Terahertz conductivity of thin metal films

Laman¹,

Grischkowsky²

2008

Applied Physics Letters

183

109

View full text Add to dashboard Cite

The conductivities of thin Al, Au, and Ag films were measured via their transmission at terahertz frequencies. The conductivities of all the films, particularly the thinner films and Al films, were much smaller than their bulk dc values. This reduced conductivity can be quantitatively understood in terms of an increased scattering rate from defects. The transmission is consistent with a frequency independent conductivity, implying a very fast electron scattering time. © 2008 American Institute of Physics. ͓DOI: 10.1063/1.2968308͔The conductivity of metals at terahertz ͑THz͒ frequencies is becoming increasingly important as both microcircuit technology and microwave resonators are being driven at ever-higher frequencies. Our earlier work with terahertz metal parallel-plate waveguides 1 has shown that the conductivity of Al and Cu at THz frequencies is considerably less than the expected handbook value, particularly at cryogenic temperatures, due to defects within the 100 nm skin-depth layer. We have now extended and confirmed these results by measuring the terahertz transmission of a number of thin films comprised of different metals and different thicknesses. Unlike our previous work, this allows us to measure the conductivity of the thin film as a function of the thickness, since we are probing the entire film and not just the skin-depth layer.Thin films of Al, Au, and Ag were deposited on highresistivity, 2 in. diameter, 0.43 mm thick Si wafers via thermal evaporation. The typical evaporation rates were 2 nm/s onto an unheated wafer in order to ensure a relatively high conductivity film. The thickness of the film was measured via a quartz thickness monitor. Six films were made in total: Al films of 36, 88, and 152 nm thickness, Au films of 85 and 150 nm thickness, and an Ag film of 86 nm thickness. The films were not annealed after evaporation. The metal coated wafers were placed in a standard terahertz time-domain spectroscopy ͑THz-TDS͒ apparatus.2,3 Their transmission was measured at both 295 and 77 K. The terahertz pulses and their amplitude spectra are shown in Fig. 1.The amplitude transmission at a frequency f of the films and wafers can be modeled by the thin film formula 4 t = t 12 t 23 t 34 exp͓i͑2hf/c͒n 2 ͔exp͓i͑2df/c͒n 3 ͔ 1 + r 12 r 23 exp͓2i͑2hf/c͒n 2 ͔ , ͑1͒where t ij and r ij are the complex Fresnel transmission and reflection coefficients, 4 respectively, medium 1 and 4 are vacuum, medium 3 is Si with a thickness d = 0.43 mm and with a THz frequency independent index n 3 = 3.4175 and negligible terahertz absorption, 5 and medium 2 is the metal film with a thickness of h and a complex index 4,6 of n 2 = ͑1 + i͒ ͱ /͑4 0 f͒. ͑2͒Propagation within the metal is described by exp͓ikz− t͔ where k = ͑2f / c͒n 2 . Using Eq. ͑2͒, one obtains the ampli-Note that ␣ is simply 1 / ␦, where ␦ is the usual result for the skin depth.6,7For our case of a 88 nm Al film with a conductivity of =16͑⍀͒ −1 , n 2 = ͑1+i͒370 at 1 THz, the resulting amplitude attenuation traversing a single pass within the metal film ͓i.e....

show abstract

Section: ͑2͒mentioning

confidence: 99%

“…9,10 The dc conductivity of thin films is considerably less than the bulk conductivity and is reduced as the thickness of the film is reduced. The general consensus is that this low conductivity is due to the scattering from grain boundaries.…”

Section: ͑2͒mentioning

confidence: 99%

Terahertz conductivity of thin metal films

Laman¹,

Grischkowsky²

2008

Applied Physics Letters

183

109

View full text Add to dashboard Cite

show abstract

“…Many measurements have demonstrated that the thermal conductivities of various thin films, as well as the electrical conductivities of electrically conductive thin films, are much smaller than those of their corresponding bulk materials [1][2][3][4][5][6]. The difference in the conductivities between thin films and bulk materials is considered to be caused by the structure defect [7], boundary scattering (surface scattering [8][9][10], and grain boundary scattering [11][12][13]). …”

Section: Introductionmentioning

confidence: 99%

Thermal and Electrical Properties of a Suspended Nanoscale Thin Film

et al. 2006

View full text Add to dashboard Cite

This paper reports on measurements of in-plane thermal conductivities, electrical conductivities, and Lorentz number of two microfabricated, suspended, nanosized thin films with a thickness of 28 nm. The effect of the film thickness on the in-plane thermal conductivity is examined by measuring other nanofilm samples with a thickness of 40 nm. The experimental results show that the electrical conductivity, resistance-temperature coefficient, and in-plane thermal conductivity of the nanofilms are much smaller than the corresponding bulk values from 77 to 330 K. However, the Lorentz number of the nanofilms is about two times that of the bulk value at room temperature, and even up to three times that of the bulk value at 77 K. These results indicate that the relation between the thermal conductivity and electrical conductivity of the nanofilms does not follow the Wiedemann-Franz law for bulk metallic materials.

show abstract

“…3 is the net resistivity at room temperature but serves as a reference by representing the temperature-independent part of the net resistivity (temperature-independent deviation from ideal Cu). [15][16][17][18][19] The DMR function, therefore, contains only the temperature-dependent portion of the deviation from ideal Cu and deviates from zero only when there is a resistivity component that shows temperature dependence.…”

Section: Theoretical Backgroundmentioning

confidence: 98%

Study of electron-scattering mechanism in nanoscale Cu interconnects

Kim

Park

Michael

et al. 2003

Journal of Elec Materi

View full text Add to dashboard Cite

This paper presents a study of electron scattering in damascene-processed Cu interconnects. To understand the leading electron-scattering mechanism responsible for the size effect, Cu interconnects with varying physical widths, 80-750 nm, were made, and their resistivity characterized as a function of temperature, ranging from liquid He temperature (4.2 K) to 500 K. The resulting data suggest that surface scattering, contrary to expectations, was not the primary cause of the size effect observed in this investigation. Surface scattering was found to weaken with decreasing line width. Further analysis leads to the conclusion that a substantial fraction of the size effect originates from impurity content scaling inversely with width in these samples.

show abstract

Temperature and thickness dependence of the resistivity of thin polycrystalline aluminium, cobalt, nickel, palladium, silver and gold films

Cited by 141 publications

References 14 publications

Terahertz conductivity of thin metal films

Terahertz conductivity of thin metal films

Thermal and Electrical Properties of a Suspended Nanoscale Thin Film

Study of electron-scattering mechanism in nanoscale Cu interconnects

Contact Info

Product

Resources

About