Self-Aligned 10-nm Barrier Layer Formation Technology for Fully Self-Aligned Metallization Metal-Oxide-Semiconductor Field-Effect-Transistor

Abstract

The technology for self-aligned 10-nm barrier layer formation on self-aligned silicidation (salicide) n+/p shallow junction has been developed for fully self-aligned metallization metal-oxide-semiconductor field-effect-transistor (FSAM-MOSFET). The features of FSAM-MOSFET are (1) self-aligned silicidation (salicide) for low Si/TiSi2 contact resistances in source/drain and gate (S/D&G) regions, (2) self-aligned barrier layer on TiSi2 surface, and (3) selective aluminum chemical vapor deposition (Al CVD) on the barrier layer surface for low sheet resistances. The FSAM structure can yield high performance with wide gate width and with localized contacts. For the self-aligned barrier layer on TiSi2 surface, a low-temperature N2 plasma nitridation has been developed. It has been experimentally confirmed that (1) aluminum is selectively deposited on the nitrided layer of TiSi2, (2) the nitrided layer acts as a barrier layer for Al, and (3) this barrier layer is a 10-nm-thick Ti–Si–N ternary amorphous layer. The combination of salicidation, the self-aligned ultrathin barrier layer formation and selective Al CVD is promising for fabricating a deep-submicron FSAM-MOSFET.