Patent ID: 8580646

Claim:
A method, comprising: forming a gate dielectric on a channel region of a doped region of a semiconductor substrate and forming a gate electrode on said gate dielectric; after forming said gate electrode, forming a conformal dielectric layer on a top surface and sidewalls of said gate electrode and top surfaces of said doped region not protected by said gate electrode; after forming said conformal dielectric layer, forming pre-source/drain extensions on opposite sides of said gate electrode, said pre-source/drain extensions extending under said gate electrode; after forming said pre-source/drain extensions, forming dielectric sacrificial sidewall spacers on regions of said conformal dielectric layer on said sidewalls of said gate electrode and on regions of said conformal dielectric layer that extend on said doped region proximate to said dielectric sacrificial sidewall spacers; after forming said sacrificial sidewall spacers, forming respective pre-source/drains in said substrate on opposite sides of said channel region and then removing said dielectric sacrificial sidewall spacers; after removing said sacrificial sidewall spacers, depositing a dielectric conformal absorption layer on the top surface of said conformal dielectric layer, said conformal dielectric layer having a dielectric constant lower than that of silicon dioxide and capable of absorbing laser radiation; irradiating said dielectric conformal absorption layer with laser radiation, said irradiation activating dopants in said pre-source/drain extensions and said pre-source/drains to form source/drains having contiguous source/drain extensions, said source/drain extensions extending under said gate electrode; and after said irradiating, forming dielectric sidewall spacers on opposite sides of said gate electrode proximate to said source/drains from said dielectric conformal absorption layer.