Lateral nonuniformity of effective oxide charges in MOS capacitors with Al/sub 2/O/sub 3/ gate dielectrics

Author

Huang, Szu-Wei ; Hwu, Jenn-Gwo

Author_Institution

Nanya Technol. Corp., Taoyuan

Volume

53

Issue

7

fYear

2006

fDate

7/1/2006 12:00:00 AM

Firstpage

1608

Lastpage

1614

Abstract

The high-frequency Terman´s method for interface-trap-density (D _it) extraction is used to examine the lateral nonuniformity (LNU) of effective oxide charges in MOS capacitors. The two-parallel-subcapacitor model is constructed to simulate LNU charges, and it was shown that the value of the found effective D_it appears negative as the LNU occurs in the gate oxide. This technique was first used to examine the effective oxide charge distribution in Al₂O₃ high-k gate dielectrics prepared by anodic oxidation and nitric-acid oxidation. It was found that the LNU effect in Al₂O₃ is sensitive to oxidation mechanisms and can be avoided by using an appropriate oxidation process. The proposed technique is useful for the preparation and reliability improvement of high-k gate dielectrics

Keywords

MOS capacitors; aluminium compounds; high-k dielectric thin films; interface states; oxidation; semiconductor device reliability; MOS capacitors; anodic oxidation; effective oxide charges; high-frequency Terman method; high-k gate dielectrics; interface-trap-density extraction; lateral nonuniformity; nitric-acid oxidation; oxidation mechanisms; preparation improvement; reliability improvement; two-parallel-subcapacitor model; Aluminum oxide; Charge pumps; Current measurement; Dielectrics; Electron traps; Hot carriers; Leakage current; MOS capacitors; Oxidation; Stress; Aluminum oxide; MOS; Terman´s method; anodization; lateral nonuniformity (LNU); nitric-acid oxidation;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2006.875816

Filename

1643494