| abstract |
A process of fabricating a CMOS device comprised with super-steep retrograde (SSR), twin well regions, has been developed. The process features the use of two, selective epitaxial growth (SEG), procedures, with the first SEG procedure resulting in the growth of bottom silicon shapes in the PMOS, as well as in the NMOS region of the CMOS device. After implantation of the ions needed for the twin well regions, into the bottom silicon shapes, a second SEG procedure is employed resulting in growth of top silicon shapes on the underlying, implanted bottom silicon shapes. An anneal procedure then distributes the implanted ions resulting in an SSR N well region in the composite silicon shape located in the PMOS region, and resulting in an SSR P well region in the composite silicon shape located in the NMOS region of the CMOS device. |