USE OF N2O AMBIENT FOR REACTIVE EVAPORATION AND OXIDATION OF Cr-CrxOy BARRIER FILMS
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-18
Cermet films of Cr-CrxOy may be used as diffusion barriers to prevent interdiffusion and reaction between the conducting metallurgy, typically Al-Cu, and the contacting metallurgy, typically Ti or PtSi. These barrier films may be formed by reactively evaporating Cr in a gaseous ambient of N2O. Upon contacting Cr, the N2O dissociates to form N2 gas that is removed by vacuum pumping, whereas the oxygen reacts with the Cr and is incorporated into the growing Cr-CrxOy film. Process repeatability may be achieved by controlling either the pressure of the reaction product, N2, or the flow rate of the reactant gas, N2O, together with the deposition rate of the Cr metal. Typically, conditions are chosen to produce Cr-CrxOy films that contain up to 25 atomic percent oxygen.