Field effect transistors having elevated source/drain regions and methods of manufacturing the same

摘要

Methods of manufacturing a field effect transistor include forming a gate pattern on a substrate. A gate spacer is formed on a sidewall of the gate pattern. A first layer is formed from a surface of the substrate and contacting the gate spacer using a first selective epitaxial growth (SEG) process at a first temperature. A second layer is formed from a surface of the first layer and contacting the gate spacer using a second SEG process at a second temperature. The second temperature is lower than the first temperature. The first and second layers define elevated source/drain regions.