LARGE DEVIATION FROM MATTHIESSENS-RULE IN CHEMICAL-VAPOR-DEPOSITED COPPER-FILMS AND ITS CORRELATION WITH NANOSTRUCTURE

The resistivity (rho) of copper films grown by varying the pressure, a nd hence the growth rate, in metalorganic chemical vapour deposition h as been studied in the temperature range 4.2 K-300 K. The films exhibi t a fairly high rho(300 K) of 8-20 mu Omega cm. Analysis of the temper ature variation of rho shows that the high rho values are not just cau sed by elastic scattering from the impurities but the temperature depe ndence of rho is also very high, resulting in a large deviation from M atthiessen's rule (DMR) in these films. This strong dependence on temp erature and DMR has been explained in a semi-quantitative manner as ar ising from grain boundary (GB) and surface scattering (SS). This is co rroborated by STM studies on the films which show that films having a smooth surface and well connected grains have a lower rho as opposed t o films with poor connectivity.