EFFECT OF THERMAL-EXPANSION OF THE GRAIN-BOUNDARY REFLECTION COEFFICIENT ON THE TEMPERATURE-COEFFICIENT OF RESISTIVITY OF THIN POLYCRYSTALLINE FILMS

Numerical values for the exact temperature coefficient of resistivity (TCR) ratio βFp/β0 of thin polycrystalline films were evaluated taking into account the influence of the thermal expansion coefficient of thickness a, the grain size ag and the grain boundary reflection coefficient r. When the thermal expansion coefficient γr related to r is less than (1 - r) × 10-5 K-1 we may conclude that for polycrystalline metallic films the TCR dependence on thickness is described with a good agreement by the approximate expression previously derived. © 1979.