Reduction of thickness variations of a threshold semiconductor alloy by reducing patterning non-uniformities prior to depositing the semiconductor alloy

摘要

The growth rate in a selective epitaxial growth process for depositing a threshold adjusting semiconductor alloy, such as a silicon/germanium alloy, may be enhanced by performing a plasma-assisted etch process prior to performing the selective epitaxial growth process. For example, a mask layer may be patterned on the basis of the plasma-assisted etch process, thereby simultaneously providing superior device topography during the subsequent growth process. Hence, the threshold adjusting material may be deposited with enhanced thickness uniformity, thereby reducing overall threshold variability.