Cmos devices containing asymmetric contact via structures

Abstract

A silicon oxide liner, a silicon nitride liner, and a planarization silicon oxide layer may be sequentially formed over p-type and n-type field effect transistors. A patterned dielectric material layer covers an entirety of the n-type field effect transistor and does not cover at least a fraction of each area of p-doped active regions. An anisotropic etch process is performed to form p-type active region via cavities extending to a respective top surface of the p-doped active regions and n-type active region via cavities having a respective bottom surface at, or within, one of the silicon nitride liner and the silicon oxide liner. Boron-doped epitaxial pillar structures may be formed on top surfaces of the p-type active regions employing a selective epitaxy process. The n-type active region via cavities are extended to top surfaces of the n-doped active regions. Contact via structures are formed in the via cavities.