Vertical natural capacitor time dependent dielectric breakdown (TDDB) improvement in 28nm

Author

Silvestre, Mary Claire ; Wenyi, Zhang Galor ; Selvam, Km Mahalingam Anbu ; Ramanathan, Eswar ; Ordonio, Christopher ; Schaller, John ; Lee Jong Hyup ; Capasso, Cristiano ; Justison, Patrick

Author_Institution

GLOBALFOUNDRIES, Malta, NY, USA

fYear

2015

fDate

3-6 May 2015

Firstpage

411

Lastpage

415

Abstract

Ultra Low-K films are used in advanced technologies as an interlayer dielectric in Cu processing. Due to its high porosity, it poses a lot of process challenges. This paper discusses one challenge it posed for reliability of vertical natural capacitors (VNCAP). When a new Cu-CMP slurry was evaluated for its improved performance for defects and uniformity, degradation of the time dependent dielectric breakdown (TDDB) lifetime for VNCAP was observed. Studies have been performed to characterize the interaction of the deposited film to the CMP process. In the course of this investigation, it was observed that the post-CMP clean chemistry impacts the TDDB lifetime. By characterizing the ULK surface post-CMP, and establishing inline correlations to TDDB lifetime, a new process was identified quickly to improve the TDDB lifetime by 2 orders.

Keywords

capacitors; chemical mechanical polishing; copper; electric breakdown; low-k dielectric thin films; porosity; semiconductor technology; Cu; TDDB lifetime; ULK surface; VNCAP; clean chemistry impact; copper processing; copper-CMP slurry; interlayer dielectric; porosity; size 28 nm; time dependent dielectric breakdown; ultra low-k film; vertical natural capacitor; Acceleration; Chemistry; Cleaning; Dielectrics; Films; Ions; Slurries; Cu CMP; TDDB; UV Cure; VNCAP; Vramp;

fLanguage

English

Publisher

ieee

Conference_Titel

Advanced Semiconductor Manufacturing Conference (ASMC), 2015 26th Annual SEMI

Conference_Location

Saratoga Springs, NY

Type

conf

DOI

10.1109/ASMC.2015.7164431

Filename

7164431