Semiconductor structure formed on a substrate and process of forming the semiconductor. The semiconductor includes a plurality of field effect transistors having a first portion of field effect transistors (FETS) and a second portion of field effect transistors. A first stress layer has a first thickness and is configured to impart a first determined stress to the first portion of the plurality of field effect transistors. A second stress layer has a second thickness and is configured to impart a second determined stress to the second portion of the plurality of field effect transistors.