Elevated source/drain with solid phase diffused source/drain extension for deep sub-micron mosfets

摘要

A method of forming an elevated source/drain structure with a solid phase diffused source/drain extension is described. A semiconductor substrate is provided having n-channel and p-channel active areas separated by isolation areas. Gate electrodes are formed overlying a gate oxide layer over each of the active areas. First spacers are formed on the sidewalls of the gate electrodes wherein the first spacers have a first dopant concentration. The first spacers in the p-channel active area are removed and second spacers are formed on the sidewalls of the gate electrodes in the p-channel active area wherein the second spacers have a second dopant concentration different from the first dopant concentration. An epitaxial layer is grown on the surface of the semiconductor substrate wherein the epitaxial layer forms the elevated source/drain structure. First ions are implanted into the n-channel active area and second ions are implanted into the p-channel active area. The first and second ions are driven in to form heavily doped regions within the semiconductor substrate underlying the elevated source/drain structure. The driving in also drives in the first and second dopant concentrations of the first and second spacers to form source/drain extensions within the n-channel and p-channel active areas underlying the first and second spacers to complete the formation of the elevated source/drain structure with solid-phase diffused source/drain extensions in the manufacture of an integrated circuit.