Process for fabricating an integrated circuit device having capacitors with a multilevel metallization

Abstract

A process for fabricating trench capacitors in an interconnect layer of a semiconductor device is disclosed. In the process, at least one interconnect is formed in the interconnect layer, which is then planarized. To form the trench capacitor, a trench is formed in the dielectric material of the interconnect. The bottom of the trench communicates with a metal contact in the underlying layer. A barrier layer of material is formed on the interconnect layer and is anisotropically etched, leaving the barrier layer on the sidewalls of the trench. The lower plate of the capacitor is then formed by depositing a layer of metal over the interconnect layer. The layer of metal is then anisotropically etched, removing the metal on the surface of the interconnect layer and leaving the metal along the trench perimeter. The capacitor dielectric layer is then deposited over the interconnect layer and subsequently patterned. Another layer of barrier material is deposited on the interconnect layer. The metal for the top plate of the capacitor is then deposited over the interconnect layer. The top plate of the capacitor extends into the trench. The metal layer and barrier layer are then patterned to form the top plate of the capacitor.