Patent ID: 8053340
Filing Date: 2011-11-08
Classification: H01L

Abstract:
1. A method for fabricating a semiconductor device comprising: providing a substrate; providing a gate stack on the substrate; implanting halo dopants into the substrate to form halo regions in the substrate adjacent to opposing sides of the gate stack, the halo regions are isolated from each other by a portion of the substrate under the gate, wherein a halo region as implanted comprises implanting first dopants to form first diffusion regions such that the first diffusion regions as implanted are contained within the halo regions and overlap both the upper vacancy rich regions and the lower buried amorphous regions, and have a dopant concentration of the first dopants that varies with depth from the surface of the substrate, the maximum dopant concentration being located at a depth Rpd from the surface of the substrate, wherein the vacancy rich region has a depth that is greater than or equal to Rpd; recrystallizing the buried amorphous regions; and activating the first dopants in the first diffusion regions wherein the crystalline upper vacancy rich region has a sufficient amount of excess vacancies to improve electrical activation in the first diffusion regions above the solid solubility limit.