Dual work function buried gate-type transistor, method for forming the same, and electronic device including the same

摘要

A transistor includes: a source region and a drain region that are formed in a substrate to be spaced apart from each other; a trench formed in the substrate between the source region and the drain region; and a buried gate electrode inside the trench, wherein the buried gate electrode includes: a lower buried portion which includes a high work-function barrier layer including an aluminum-containing titanium nitride, and a first low-resistivity layer disposed over the high work-function barrier layer; and an upper buried portion which includes a low work-function barrier layer disposed over the lower buried portion and overlapping with the source region and the drain region, and a second low-resistivity layer disposed over the low work-function barrier layer.

主权项

1. A method for fabricating a transistor, comprising:
forming an isolation layer that defines an active region in a substrate; forming a trench extending across the active region and the isolation layer; forming a fin region by recessing the isolation layer, after the forming of the trench; forming a lower buried gate electrode that includes a high work-function barrier layer disposed on a bottom and sidewalls of the trench and fills a portion of the trench; forming an upper buried gate electrode over the lower buried gate electrode, wherein the upper buried gate electrode includes a low work-function barrier layer and fills a portion of the trench; forming a capping layer over the upper buried gate electrode; and forming a source region and a drain region that are spaced apart from each other by the trench in the substrate and each have a depth overlapping with the low work-function barrier layer.