Transistor having high mobility channel and methods

Abstract

Methods and resulting structure of forming a transistor having a high mobility channel are disclosed. In one embodiment, the method includes providing a gate electrode including a gate material area and a gate dielectric, the gate electrode being positioned over a channel in a silicon substrate. A dielectric layer is formed about the gate electrode, and the gate material area and the gate dielectric are removed from the gate electrode to form an opening into a portion of the silicon substrate that exposes source/drain extensions. A high mobility semiconductor material, i.e., one having a carrier mobility greater than doped silicon, is then formed in the opening such that it laterally contacts the source/drain extensions. The gate dielectric and the gate material area may then be re-formed. This invention eliminates the high temperature steps after the formation of high mobility channel material used in related art methods.