Metal Wet Cleaning with No Corrosion: A Novel Approach

摘要

In order to improve the quality of the surfaces of new materials electrodes and the adhesion of metal lines, a new cleaning procedure is required, providing particle and organic free surfaces plus low metal and oxide etch rate. Moreover, given that new materials with higher thermal stability and lower sheet resistance will substitute the existent electrodes or metal lines, a detailed analysis of these materials is needed to reach a satisfying cleaning sequence. Finally, until now different cleanings were performed depending on the purpose (alkali-based solution for W surfaces, solvent for Al and so on) leading to the need of different equipments and chemicals and consequently to a large money investment. Our study is aimed at the definition of a cleaning sequence that is efficient on the materials in analysis, but that doesn't have any impact on the layer thickness or on the surrounding isolation. The pointed out concept is working on all the materials tested allowing believing that different equipments won't be needed anymore. The project includes three major issues: 1. material etch rate in various chemicals and selection of the most interesting mixtures; 2. particle removal efficiency of selected mixtures on Si oxide 3. organic removal Hereafter, we will follow 4 of the 15 different materials under examination, through the different mixtures tested.