Sealed Contact Hole
Original Publication Date: 1983-Dec-01
Included in the Prior Art Database: 2005-Feb-07
A process is provided which produces complete coverage of contacts with metal even though a layer of silicon dioxide may be undercut with respect to an opening in an overlying layer of silicon nitride when using a wet etchant. This process eliminates or at least minimizes defects in openings which may be caused by, e.g., aluminum spikes, or shorts, discontinuities and leakage. As seen in Fig. 1, the process includes growing a layer 10 of silicon dioxide, which may have varying thicknesses, on a silicon substrate 12 and depositing a layer 14 of silicon nitride on layer 10. Contact openings 16 and 18 are then formed in silicon nitride layer 14 with silicon dioxide layer 10 being undercut, as indicated at 16' and 18', by any suitable wet etching process to expose portions of the surface of substrate 12.