Optical induce tungsten plug corrosion in CMP process

Author

Chiu, Re-Long ; Higgins, Jason ; Ying, Sharon ; Liu, Yajiang ; Dick, Barry ; Peterson, Brian ; Nyi, Ohnmar ; Chung, Wen-Szu

Author_Institution

WaferTech LLC, Camas, WA, USA

fYear

2010

fDate

5-9 July 2010

Firstpage

1

Lastpage

5

Abstract

Optically induced tungsten plug (W-plug) corrosion defects on wafers stored in a water tank waiting for a cleaning treatment during post tungsten chemical mechanical planarization (WCMP) were verified using KLA scan, queue-time (Q-time) splits, layout tracing, SEM/FIB inspection and electric measurement. Reliability tests on an out of control limitation lot also found W-plug corrosion interconnect failures as Q-time went overdue with the defects experiencing a layout dependency. The W-plug corrosion mechanism is being proposed in this article. The installation of yellow lights in the WCMP environment could make Q-time longer but does not completely solve the issue.

Keywords

chemical mechanical polishing; cleaning; scanning electron microscopy; tungsten; KLA scan; SEM-FIB inspection; cleaning treatment; electric measurement; layout tracing; optical induce tungsten plug corrosion; post tungsten chemical mechanical planarization; queue-time splits; reliability tests; tungsten-plug corrosion interconnect failures; water tank; Cleaning; Corrosion; Electric variables measurement; Inspection; Mechanical variables measurement; Planarization; Plugs; Testing; Tungsten; Water storage;

fLanguage

English

Publisher

ieee

Conference_Titel

Physical and Failure Analysis of Integrated Circuits (IPFA), 2010 17th IEEE International Symposium on the

Conference_Location

Singapore

ISSN

1946-1542

Print_ISBN

978-1-4244-5596-6

Type

conf

DOI

10.1109/IPFA.2010.5532231

Filename

5532231