Process and reliability of SF6/O2 plasma etched copper TSVs

Author

Filipovic, Lado ; de Orio, R.L. ; Selberherr, Siegfried

Author_Institution

Inst. for Microelectron., Tech. Univ. Wien, Vienna, Austria

fYear

2014

fDate

7-9 April 2014

Firstpage

1

Lastpage

4

Abstract

The formation of a TSV for three-dimensional interconnects using SF₆/O₂ plasma is explored. Adjusting the O₂ gas concentration to 45 sccm, while the SF₆ concentration is set to 35 sccm, produced the best combination of chemical and physical etching to provide sidewall angles of 88°. Three TSV aspect ratios are etched (5/58, 10/100, and 20/100 μm) and subsequently analyzed using the finite element method. The TSVs´ series resistance, current density, thermo-mechanical stress, and electromigration induced stress after 300 hours of operation at a 2MA/cm² current density are analyzed. An additional comparison to ideal TSVs with sidewall angles at 90° is performed.

Keywords

current density; electromigration; etching; finite element analysis; integrated circuit interconnections; integrated circuit reliability; sputter etching; three-dimensional integrated circuits; Cu; SF₆-O₂; chemical etching; current density; electromigration; finite element method; gas concentration; physical etching; plasma etched copper TSV; reliability; series resistance; thermomechanical stress; three-dimensional interconnects; time 300 hour; Abstracts; Etching; Presses; Reliability; Silicon; Stress; Sulfur hexafluoride;

fLanguage

English

Publisher

ieee

Conference_Titel

Thermal, mechanical and multi-physics simulation and experiments in microelectronics and microsystems (eurosime), 2014 15th international conference on

Conference_Location

Ghent

Print_ISBN

978-1-4799-4791-1

Type

conf

DOI

10.1109/EuroSimE.2014.6813768

Filename

6813768