Determination of the Roughness of Aluminium Films by the Anodization Profiles Method for Nanotechnologies Based on Porous Anodic Alumina

Nanostructered porous anodic alumina (PAA) and nanostructures based on PAA are widely used in microelectronics, sensorics, photonics, etc. Uniformity and ordering of PAA films manufactured from Al thin films on the substrates are influenced by structure and roughness of the initial aluminum films. In this regard, when developing a technology, it is desirable to use a fast method of express control. The tasks of express control of surface roughness can be performed by the inexpensive and fast method named anodization spectroscopy consists of monitoring and analysis of anodizing profiles dV/dt(V) during anodic oxidation with formation of a dense anodic oxide. In the work the results of studies carried out using the developed technique of anodization spectroscopy gives opportunity to provide express control of surface roughness and estimate its value for Al films are presented. The technique is realized by deposition of Nb/Al structures and anodic oxidation of fixed area in capillary electrochemical cell with in-situ monitoring dV/dt(V). It was shown, that developed technique gives an opportunity to estimate roughness of aluminum films (about 5 nm for Al thickness of 45 nm and about 30 nm for Al thickness of 510 nm). The obtained results reflect an increase in the number and size of protruding crystallites on the surface of the Al film with an increase of its thickness in accordance with conventional dates and show the possibility of express control by the method.