Bird's Beak-Free Recessed Oxide Isolation by O2 Ion Implantation
Original Publication Date: 1983-Jul-01
Included in the Prior Art Database: 2005-Feb-07
One of the major problems of the recessed oxide isolation (ROI) formed by the conventional localized oxidation method is the existence of the so-called "bird's beak" which reduces the area on a semiconductor wafer available for device construction. To circumvent the problem, a procedure which utilizes oxygen (O2) ion implantation to form the ROI is used. Since no oxygen diffusion is involved in the ROI growth, the problem of O2 diffusion along the ROI silicon nitride mask/silicon substrate interface is avoided, and the ROI thus formed will be substantially bird's beak-free.