| abstract |
A method includes isolating a first and at least a second region on a semiconductor substrate, and forming one or more devices on each of the first and at least second regions. Forming the one or more devices includes forming at least one gate structures in each of the first and at least second regions on a first surface of the substrate, depositing a spacer over the gate structures in each of the first and the at least second regions and over the first surface of the substrate, etching horizontal portions of the spacer in the first region, growing epitaxial portions in the first region in alignment with said at least one gate structure in the first region, oxidizing exposed surfaces of the epitaxial portions in the first region, and repeating the etching, growing and oxidizing steps for the at least second region. |