Kinetics of copper drift in PECVD dielectrics

Author

Loke, Alvin L S ; Ryu, Changsup ; Yue, C. Patrick ; Cho, James S H ; Wong, S. Simon

Author_Institution

Center for Integrated Syst., Stanford Univ., CA, USA

Volume

17

Issue

12

fYear

1996

Firstpage

549

Lastpage

551

Abstract

We quantified the drift of Cu ions into various PECVD dielectrics by measuring shifts in capacitance-voltage behavior after subjecting Cu-gate MOS capacitors to bias-temperature stress. At a field of 1.0 MV/cm and temperature of 100/spl deg/C, Cu ions drift readily into PECVD oxide with a projected accumulation of 2.7/spl times/10/sup 13/ ions/cm/sup 2/ after 10 years. However, in PECVD oxynitride, the projected accumulation under the same conditions is only 2.3/spl times/10/sup 10/ ions/cm/sup 2/. These findings demonstrate the necessity of integrating drift barriers, such as PECVD oxynitride layers, in Cu interconnection systems to ensure threshold stability of parasitic field n-MOS devices.

Keywords

CVD coatings; MOS capacitors; copper; dielectric thin films; diffusion; 100 C; Cu; Cu-gate MOS capacitor; PECVD dielectric; bias-temperature stress; capacitance-voltage characteristics; copper ion drift kinetics; drift barrier; interconnection; oxide layer; oxynitride layer; parasitic field n-MOS device; threshold stability; Capacitance measurement; Capacitance-voltage characteristics; Copper; Dielectric measurements; Dielectric substrates; Kinetic theory; MOS capacitors; Plasma temperature; Temperature distribution; Testing;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/55.545766

Filename

545766