Inner size effect of temperature coefficient of resistance in Cu, Ag, V and Mo films

Nanostructured Silver Films with a Low Coefficient of Thermal Expansion as a Promising Material for Nanoelectronics

“…In this case, taking into account the size dependence of the diffusion coefficient, [ 9,10 ] it is reasonable to expect that the most intense increase in the area of crystallites occurs precisely in the first heating cycle. The results of the study of the temperature dependence of the resistance [ 1 ] also indicate the preservation of the approximate constancy of the grains sizes of films Ag and other metals after the first heating of as‐deposited samples. According to Bogatyrenko et al, [ 7,8 ] an irreversible decrease in the film resistance ( R ) occurs during their first heating for several minutes.…”

“…At the same time, the possibility of lowering the melting temperature associated with the internal boundaries of the samples [5,6] can be interpreted within the framework of the classical Clausius-Clapeyron model in terms of the increased pressure created by the grain or interfacial boundary. Thus, it can be assumed that the nanosized fraction of crystallites forming Ag films is under conditions of compressive stresses which are due to their grain boundaries.…”

“…At the same time, the nanocrystalline structure of films can lead to a number of particularities, which must be taken into account for their application. So, in addition to the already noted decrease in the temperature coefficient of resistance, [ 1 ] a growth in solubility can take place in films. [ 2–4 ] The given factor can be used to create functional transition zones, but, generally speaking, it contributes to the degradation of devices.…”

“…Furthermore, according to Dukarov et al, [ 1 ] the temperature coefficient of resistance of nanocrystalline films of silver, as well as of some other metals and alloys, [ 1–4 ] turns out to be significantly lower than in the bulk. This can be explained by an increase in the contribution of grain‐boundary electrons scattering, [ 2 ] which, in some cases, can lead [ 3 ] and leads [ 1 ] to a negative value of TCR. The low value of the temperature coefficient of resistance simplifies the design of end devices.…”

“…The significant thickness of the samples allows supposing that, in this case, the increase in solubility should be considered not as a consequence of the small thickness of the film, but as one of the manifestations of the inner size effect. [5,6] Such effects are due to the inner boundaries of the samples, primarily due to grain boundaries in polycrystalline films and interfacial surfaces in multicomponent structures. Thus, inner size effects do not depend on the contribution of the external surface to the behavior of the sample, but are determined by its internal structure.…”