Performance enhancement in transistors by providing a graded embedded strain-inducing semiconductor region with adapted angles with respect to the substrate surface

Abstract

In sophisticated semiconductor devices, transistors may be formed on the basis of an efficient strain-inducing mechanism by using an embedded strain-inducing semiconductor alloy. The strain-inducing semiconductor material may be provided as a graded material with a smooth strain transfer into the neighboring channel region in order to reduce the number of lattice defects and provide enhanced strain conditions, which in turn directly translate into superior transistor performance. The superior architecture of the graded strain-inducing semiconductor material may be accomplished by selecting appropriate process parameters during the selective epitaxial growth process without contributing to additional process complexity.