In situ planarization of dielectric surfaces using boron oxide

A novel integrated in situ approach to deposition and planarization of dielectrics is presented. The process uses a multichamber deposition and etch system. A sacrificial layer of boron oxide is deposited by plasma-enhanced deposition over the dielectric material. Boron oxide is observed to flow as deposited, resulting in a planarized surface. After deposition the wafer is transferred under vacuum to the etch chamber where the boron oxide is removed with a 1:1 dielectric-to-boron-oxide etch. This results in a planarized dielectric surface. Effective planarization of 25-μ-wide spacings can be achieved using this process