Reducing the Grain Size of Vapor Deposited Thin Films by the Joint Application of a Barrier to Grain Growth and a Nucleating Agent
Original Publication Date: 1983-Jan-01
Included in the Prior Art Database: 2005-Feb-06
In order to sustain thermal stresses which arise upon temperature change due to the difference in the coefficients of thermal expansion of film and substrate materials, the mechanical strength of thin films must be increased. This is of particular concern in the case of lead alloy Josephson electrodes which represent the highest thermal stresses in thin film devices due to the greatest difference in the coefficients of thermal expansion between film (Pb)and substrate (Si) and a repeatedly occurring 300K temperature change. The most efficient way to increase the strength of polycrystalline thin films is by reducing grain size.