https://doi.org/10.1051/epjap/2010100404
Resistance and 1/f noise between circular contacts on conductive thin films
1
Université Lille Nord de France, 59000 Lille, France
2
Unité de Dynamique et Structure des Matériaux
Moléculaires, Université du Littoral Côte d'Opale, 50 rue F.
Buisson, BP 717, 62228 Calais, France
3
Eindhoven University of Technology, Department of Electrical
Engineering PT 913, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
Corresponding author: Liang@univ-littoral.fr
Received:
14
October
2010
Accepted:
21
December
2010
Published online:
22
February
2011
There is a need to characterize the quality of contacts and the noise
properties of new materials deposited or grown as thin films. Poor contacts
are interface dominated. Perfect contacts have a negligible interface
contribution and there is only a resistance and noise contribution from
outside the contact region. The presence of current crowding enhances the
resistance and noise contribution. Such contacts are called constriction
dominated contacts. The conductive film is characterized by its sheet
resistance and normalized conductance fluctuations for a unit surface. The
resistance and noise is studied between two circular top electrodes of the
same diameter on the conductive. To distinguish between perfect and poor
contacts and to characterize the thin film in case of good contacts, we need
a set of contacts with different diameters.
Models for perfect and poor contacts are investigated. The scaling of
resistance and noise with contact radius r is for interface dominated poor
contacts: Ri 
1/r2 and SRi 1/r6. In
contrast, perfect contacts with contact diameter (2r) much smaller than the
distance between the centers (2b) show: Rc ln(b/r) and
SRc 1/r2. From the resistance and noise measurements
between constriction dominated perfect contacts, the sheet resistance and
normalized noise of the thin film are calculated.
© EDP Sciences, 2011
