Super Halo Formation Using a Reverse Flow for Halo Implants

摘要

Shrinking dimensions of MOS transistors in integrated circuits requires tighter distributions of dopants in pocket regions from halo ion implant processes. In conventional fabrication process sequences, halo dopant distributions spread during source/drain anneals. The instant invention is a method of fabricating MOS transistors in an integrated circuit in which halo ion are performed after source/drain anneals. In the inventive method, source/drain spacers on MOS gate sidewalls are removed prior to halo ion implant processes. Spacers to offset metal silicide are formed after halo implants and may be of low-k dielectric material to reduce gate to drain capacitance. A compressive stress layer may be deposited on MOS gates after source/drain spacers are removed for greater stress transfer efficiency to the MOS gates. An integrated circuit embodying the inventive method is also disclosed.