Patent ID: 7170084
Filing Date: 2007-01-30
Classification: H01L

Abstract:
1. An n-type metal oxide semiconductor field effect transistor (MOSFET) device, comprising: a substrate comprising a layer of silicon germanium having a layer of strained silicon formed thereon; a gate insulator formed on the strained silicon layer; a gate formed on the gate insulator; deep source and drain regions formed in the substrate on opposing sides of the gate; shallow source and drain extensions formed in the strained silicon layer and the silicon germanium layer and extending from the deep source and drain regions toward a channel region of the MOSFET; a first pair of halo regions formed in the strained silicon layer; and a second pair of halo regions formed in the silicon germanium layer, the first halo regions and the second halo regions extending toward the channel region of the MOSFET beyond ends of the shallow source and drain extensions, the first halo regions extending further toward the channel region than the second halo regions, the second halo regions extending into the silicon germanium layer beyond a depth of said shallow source and drain extensions, the second halo regions extending deeper into the substrate than the first halo regions, the first halo regions extending into the silicon germanium layer, and the second halo regions extending further into the silicon germanium layer than the first halo regions, the first and second halo regions comprising p-type dopant and the shallow source and drain extensions comprising an n-type dopant.