In situ atomic layer nitridation on the top and down regions of the amorphous and crystalline high-K gate dielectrics
Journal
Applied Surface Science
Journal Volume
387
Pages
274-279
Date Issued
2016
Author(s)
Abstract
Amorphous and crystalline ZrO 2 gate dielectrics treated with in situ atomic layer nitridation on the top and down regions (top and down nitridation, abbreviated as TN and DN) were investigated. In a comparison between the as-deposited amorphous DN and TN samples, the DN sample has a lower leakage current density (J g ) of ∼7 × 10 −4 A/cm 2 with a similar capacitance equivalent thickness (CET) of ∼1.53 nm, attributed to the formation of SiO x N y in the interfacial layer (IL). The post-metallization annealing (PMA) leads to the transformation of ZrO 2 from the amorphous to the crystalline tetragonal/cubic phase, resulting in an increment of the dielectric constant. The PMA-treated TN sample exhibits a lower CET of 1.22 nm along with a similar J g of ∼1.4 × 10 −5 A/cm 2 as compared with the PMA-treated DN sample, which can be ascribed to the suppression of IL regrowth. The result reveals that the nitrogen engineering in the top and down regions has a significant impact on the electrical characteristics of amorphous and crystalline ZrO 2 gate dielectrics, and the nitrogen incorporation at the top of crystalline ZrO 2 is an effective approach to scale the CET and J g , as well as to improve the reliability.
SDGs
Publisher
Elsevier B.V.
Type
journal article