Process Improvement for Deposited Ohmic Contacts
Original Publication Date: 1982-Aug-01
Included in the Prior Art Database: 2005-Feb-09
Circuit components which utilize tantalum as a low barrier Schottky metallurgy experience significant contact resistance when standard Purdue first level metallization (Cr, Al-Cu) is employed. The cause of contact resistance is an undefined, interfacial film produced between the tantalum and chromium which is not dispersed by subsequent sintering. By opening the shutter prior to attaining evaporation power necessary to deposit the wafer-bled chromium film on the tantalum underlayer, the contact resistance is improved without degrading the diffusion barrier characteristics of the Cr/Cr(2)O(3) layer.