Reliability degradation impact by ultra low-k dielectrics and improvement study for BEOL process beyond 28nm technology

Author

Fanfei Bai ; Xinghua Song

Author_Institution

Technol. R&D, Semicond. Manuf. Int. Corp., Shanghai, China

fYear

2015

fDate

15-16 March 2015

Firstpage

1

Lastpage

3

Abstract

As CMOS is being scaled down to 28nm node and beyond, BEOL process must use ultra low-K film as inter-metal dielectric (IMD) layers to reduce interconnection RC delay. Compared to low-K film, ultra-low K film (K≤2.5) is more porous, softer and more hydrophilic intrinsically, and easy to be damaged by process plasma, film stress, thermal and aqueous environments. The paper focuses mainly on the BEOL processes, such as etch PET, metallization, CMP, thermal treatment impact of ultra low-k dielectrics on reliability performance of electromigration (EM) and time-dependent dielectric breakdown (TDDB) or dielectric voltage breakdown (VBD). Some optimized BEOL processes with improved control of damage on porous low k materials could lead to an acceptable EM and TDDB performance.

Keywords

CMOS integrated circuits; chemical mechanical polishing; electric breakdown; electromigration; hydrophilicity; integrated circuit interconnections; integrated circuit metallisation; low-k dielectric thin films; nanoelectronics; BEOL process; CMOS; CMP; IMD layer; PET; TDDB; VBD; aqueous environment; back end of line process; chemical mechanical polishing; complementary metal-oxide semiconductor; dielectric voltage breakdown; electromigration; film stress; hydrophilicity; interconnection RC delay; intermetal dielectric layer; metallization; process plasma; reliability degradation impact; size 28 nm; thermal environment; time-dependent dielectric breakdown; ultra low-k dielectric film; Dielectrics; Films; Materials reliability; Moisture; Nitrogen; Semiconductor device reliability; BEOL process; Reliability degradation; reliability improvement; ultra-low K film damage;

fLanguage

English

Publisher

ieee

Conference_Titel

Semiconductor Technology International Conference (CSTIC), 2015 China

Conference_Location

Shanghai

ISSN

2158-2297

Type

conf

DOI

10.1109/CSTIC.2015.7153429

Filename

7153429