SEMICONDUCTOR DEVICES AND METHODS FOR FABRICATING THE SAME

摘要

A semiconductor device includes a substrate including a first region and a second region, a first gate dielectric layer, a first lower gate electrode, and a first upper gate electrode sequentially stacked on the first region, a second gate dielectric layer, a second lower gate electrode, and a second upper gate electrode sequentially stacked on the second region, a first spacer disposed on a sidewall of the first upper gate electrode, a second spacer disposed on a sidewall of the second upper gate electrode, a third spacer covering the first spacer on the sidewall of the first upper gate electrode, and a fourth spacer covering the second spacer on the sidewall of the second upper gate electrode. At least one of a first sidewall of the first lower gate electrode and a second sidewall of the first lower gate electrode is in contact with the third spacer.

主权项

1. A method for fabricating a semiconductor device, comprising:
forming a first gate structure and a second gate structure on a first region and a second region of a substrate, respectively, wherein each of the first and second gate structures including a gate dielectric layer, a metal gate electrode, and a semiconductor gate electrode which are sequentially stacked; forming an inner spacer on a sidewall of each of the first and second gate structures; removing a portion of the metal gate electrode exposed by the inner spacer on the first region to form an undercut region; and forming an outer spacer filling the undercut region on each of the inner spacers.