METHODS OF FORMING TRANSISTORS WITH RETROGRADE WELLS IN CMOS APPLICATIONS AND THE RESULTING DEVICE STRUCTURES

摘要

One illustrative method disclosed herein includes performing a first plurality of epitaxial deposition processes to form a first plurality of semiconductor materials selectively above the N-active region while masking the P-active region, performing a second plurality of epitaxial deposition processes to form a second plurality of semiconductor materials selectively above the P-active region while masking the N-active region, forming an N-type transistor in and above the N-active region and forming a P-type transistor in and above the P-active region.

主权项

1. A method, comprising:
forming an N-active region and a P-active region in a semiconductor substrate; performing a common etching process to form recesses in said N-active region and said P-active region such that said N-active region and said P-active region have recessed surfaces; performing a first plurality of epitaxial deposition processes to form a first plurality of semiconductor materials selectively above said N-active region while masking said P-active region, wherein performing said first plurality of epitaxial deposition processes comprises forming a layer of silicon-carbon on said recessed surface of said N-active region and forming a first layer of a first semiconductor material on said layer of silicon-carbon; performing a second plurality of epitaxial deposition processes to form a second plurality of semiconductor materials selectively above said P-active region while masking said N-active region, wherein performing said second plurality of epitaxial deposition processes comprises forming a second layer of said first semiconductor material on said recessed surface of said P-active region and forming a layer of a second semiconductor material on said second layer of said first semiconductor material, wherein said first semiconductor material is a different semiconductor material from said second semiconductor material; forming an N-type transistor in and above said N-active region; and forming a P-type transistor in and above said P-active region.