Structure of Aluminum Films for the Creation of Tunnel Junctions

A series of studies of the structure of aluminum films deposited on single-crystal silicon substrates in different temperature regimes has been carried out. The roughness and grain size of 20-nm thick films of nuclei deposited at elevated temperatures and also dusted over the nucleus layer at room temperature to a thickness of 150 nm was studied using an atomic force microscope. The film profile was measured in an electron microscope. It is found that films on a hot sublayer turn out to be smoother, more rigid (less friable), and make it possible to expect the creation of superconductor–insulator–superconductor and superconductor–insulator–normal metal transitions with a higher current density and lower capacitance, respectively.