9701972 Pohl This is a renewal proposal on the elastic properties of thin metal films. A new technique has been developed with which the shear modulus and internal friction of films with thicknesses as small as 10 nm on silicon substrates can be measured at low temperatures. The substrates are couleDpaddle oscillators which are chemically etched out of 0.3 mm thick ultrahigh purity silicon wafers. These oscillators are to be used to study polycrystalline metal films deposition by various techniques. in which exploratory measurements have revealed an internal friction which resembles that of amorphous solids. It is remarkably independent of the metal used, and at this point shows little dependence on the way in which the film has been deposited. As a possible explanation, tunneling states of dislocations will be explored. %%% This is a renewal proposal on the elastic properties of thin metal films. This metal films on substrates are often used, e.g., as current leads in the microelectronic devices. In order to ensure their performance, defects in such films have to be identified and controlled. In previous work, we have developed a new technique for measuring elastic constants of crystalline metal films on silicon substrates. We have found that all films measured so far hjave an internal friction at low temperatures which resembles that of amorphous solids, indicating a considerable amount of disorder. The objective of this investigation is to identify this disorder, and to find ways to reduce it.
