THE EFFECT OF STRAIN ON THE ELECTRICAL RESISTIVITY OF THIN FILMS

This work reports the effect of strain on the electrical resistance of continuous metal and metal/insulator composite films. A novel expression for the effect of strain on the effective number of free electrons per unit volume is derived, and incorporated into a current theoretical model which describes the effect of strain on the resistivity of thin polycrystalline metal films. Residual resistance measurements have been made on metal films, allowing the measured gauge factor to be altered to a form more suitable for comparison with theoretical models. The gauge factor of gold films prepared using a liquid metal ion source has been measured, and comparisons are made with gauge factor measurements made on vacuum evaporated gold films of similar film thickness. Films prepared using these techniques exhibit different gauge factors. This difference in gauge factor is discussed in terms of the difference in microstructure of films produced by these methods. The effect of surface roughness on the gauge factor of vacuum evaporated gold films is reported and comparisons are made between the measured gauge factors and appropriate theoretical models. The effect of sheet resistance and film composition on the gauge factor and temperature coefficient of resistance, (T.C.R.), of Cr-SiO cermet films is reported for films prepared using flash evaporation and R.F. sputtering, and discussed in terms of mixed activated and metallic conduction. Further, a monatonic relationship between the measured gauge factor and T.C.R. for cermet films is established. The gauge factor of fluorocarbon-polymer gold films and the gauge factor and T.C.R. of aluminium/aluminium oxide films have been measured. The measured gauge factors are discussed in terms of a meandering three-dimensional conduction path.

Name dc:type.qualificationname

PhD

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

De Montfort University

Year dc:date.issued

1985

Author dc:creator

• Taylor, Alan Geoffrey

Licence

• https://dora.dmu.ac.uk/bitstreams/09b44ac0-c95a-43b7-9fe4-897f0f0d4798/download