Effects of copper CMP and post clean process on VRDB and TDDB at 28nm and advanced technology node

Author

Li Chieh Hsu ; Yu Min Lin ; Chien Liang Wu ; Wei Kun Lee ; Yen Chun Liu ; Cheng Pu Chiu ; Hsin Kuo Hsu ; Chun Yi Wang ; Chien Chung Huang ; Chin Fu Lin

Author_Institution

Adv. Technol. Dev. Div., United Microelectron. Corp., Tainan, Taiwan

fYear

2015

fDate

19-23 April 2015

Abstract

Optimization of the polishing and cleaning steps during the copper chemical mechanical polishing (Cu CMP) process can be accomplished by modification of Cu trench profile, control of Cu surface roughness, and reduction of residual Cu ions on the ultra-low k (ULK) surface. For the tuning of the polishing process, the optimized profile will improve the sheet resistance (Rs) and TDDB (time-dependent dielectric breakdown). The cleaning effectiveness would be influenced by the clean chemicals and clean process. The correlation between cleaning effectiveness and voltage ramp dielectric breakdown (VRDB) was investigated. In addition, inductively coupled plasma mass spectrometry (ICP-MS) was found to be a useful tool for the evaluation of post cleaning performance.

Keywords

chemical mechanical polishing; copper; electric breakdown; mass spectroscopy; optimisation; surface cleaning; surface roughness; Cu; TDDB; ULK surface; VRDB; chemical mechanical polishing; copper CMP; inductively coupled plasma mass spectrometry; optimization; polishing process; post cleaning performance; residual ion reduction; sheet resistance; size 28 nm; surface roughness; time-dependent dielectric breakdown; trench profile; ultralow k surface; voltage ramp dielectric breakdown; Chemicals; Copper; Dielectric breakdown; Ions; Surface cleaning; CMP; TDDB; VRDB; profile;

fLanguage

English

Publisher

ieee

Conference_Titel

Reliability Physics Symposium (IRPS), 2015 IEEE International

Conference_Location

Monterey, CA

Type

conf

DOI

10.1109/IRPS.2015.7112775

Filename

7112775