SELECTIVE DEPOSITION OF POLYCRYSTALLINE SILICON
Original Publication Date: 1988-Oct-01
Included in the Prior Art Database: 2001-Oct-31
Continued reduction of feature size into the submicron regime in IC devices has caused severe difficulty in multilayered metallization. For example, electrical contact to the substrate can no longer be simply done by direct deposition of a metal film such as Al into the contact holes. This is due to the fact that conformal deposition of the metal film is very difficult to obtain at the sidewalls of the contact holes because of the sharp steps. This problem can be solved if the contact holes are prefilled with a material to plug the contact holes and form a planar surface. An ideal material to plug the contact holes should be a highly electrical conductive and refractive metal such as W. However, filling with heavily doped silicon is also very promising since it eliminates the material incompatibility between the filler and substrate silicon.