Patent ID: 8255843

Claim:
A method of making a semiconductor device, comprising the steps of: providing a semiconductor substrate, the substrate having an upper surface; receiving a design layout to be implemented on the semiconductor substrate, the design layout including a plurality of active areas configured for selective epitaxial growth; partitioning the design layout into sub blocks; for each of the sub blocks, determining a local epitaxial concentration ratio percentage within the sub block; selecting one or more low epitaxial concentration sub blocks by determining whether the local epitaxial concentration ratio percentage of each sub block is below a predetermined minimum percentage; increasing the local epitaxial concentration ratio percentage by modifying the design layout within the selected one or more low epitaxial concentration sub blocks to add dummy areas configured for selective epitaxial growth until the local epitaxial concentration ratio percentage within the selected one or more low epitaxial concentration sub blocks exceeds the predetermined minimum percentage; calculating for the design layout a global epitaxial concentration ratio percentage by combining the local epitaxial concentration ratio percentages for the sub blocks; determining whether the global epitaxial concentration ratio percentage is below a predetermined minimal global epitaxial concentration ratio percentage; subject to the determining whether the global epitaxial concentration ratio percentage is below a predetermined minimal global concentration ratio percentage, identifying selected sub blocks with area available for additional selective epitaxial growth; for the selected sub blocks identified with area available, increasing the local epitaxial concentration ratio percentage by adding additional dummy areas configured for selective epitaxial growth; repeating the determining whether the global epitaxial concentration ratio percentage is below the predetermined minimal global epitaxial concentration ratio percentage, the identifying selected sub blocks with area available, and the increasing the local epitaxial concentration ratio percentage until the global epitaxial concentration ratio percentage for the design layout exceeds the predetermined minimal global epitaxial concentration ratio percentage; and using the design layout including the modifications made to the design layout, performing selective epitaxial growth on the surface of the semiconductor substrate.