Visualization of progressive breakdown evolution in gate dielectric by conductive atomic force microscopy

Author

Zhang, Li ; Mitani, Yuichiro ; Satake, Hideki

Author_Institution

Adv. Large-Scale Integration, Corp. R&D Center, Kawasaki

Volume

6

Issue

2

fYear

2006

fDate

6/1/2006 12:00:00 AM

Firstpage

277

Lastpage

282

Abstract

To understand the breakdown (BD) mechanism in gate oxide of MOSFET, BD evolution is investigated by a conductive atomic force microscope. High electric fields of both polarities are applied to induce a pre-BD degradation and a BD transient. Structural hillocks and negative charges are simultaneously observed at both pre- and post-BD stages. The hillocks show stress-polarity dependence, and the height increases with BD evolution. A flat-band shift caused by negative charges does not depend on stress polarity. Lateral size of the hillocks and the electrical degradation remains similar throughout the BD evolution. Progressive structural evolution of dielectric BD is confirmed, where polarity-dependent Si deformation plays an important role

Keywords

MOSFET; atomic force microscopy; semiconductor device breakdown; semiconductor device testing; MOSFET; conductive atomic force microscopy; dielectric breakdown; electric fields; electrical degradation; flat-band shift; gate dielectric; gate oxide; negative charges; progressive breakdown evolution; progressive structural evolution; stress-polarity dependence; structural hillocks; Atomic force microscopy; Degradation; Dielectric breakdown; Laboratories; Large scale integration; MOSFET circuits; Planning; Research and development; Transmission electron microscopy; Visualization; Breakdown (BD); conductive atomic force microscopy (CAFM); gate dielectric;

fLanguage

English

Journal_Title

Device and Materials Reliability, IEEE Transactions on

Publisher

ieee

ISSN

1530-4388

Type

jour

DOI

10.1109/TDMR.2006.876579

Filename

1673720