Reliability characteristics and surface preparation technique for ultra-thin (33 /spl Aring/-87 /spl Aring/) oxides and oxynitrides

Author

Ming-Yin Hao ; Kafai Lai ; Wei-Ming Chen ; Lee, J.C.

Author_Institution

Dept. of Electr. & Comput. Eng., Texas Univ., Austin, TX, USA

fYear

1994

fDate

11-14 Dec. 1994

Firstpage

601

Lastpage

604

Abstract

Surface preparation, dielectric breakdown and stress-induced leakage current effects are some of the most Important issues for ultrathin dielectric processes. In this paper, a novel "two-step dip" wafer-cleaning procedure is proposed for ultra-thin dielectric growth. Improved dielectric integrity has been observed for ultra-thin thermal oxides and N/sub 2/O oxynitrides fabricated using this surface preparation technique. Dielectric breakdown mechanism for the ultra-thin N/sub 2/O oxynitrides was also investigated in this study. It was found that holes generated within the dielectrics were responsible for the catastrophic breakdown for both thermal oxides and N/sub 2/O oxynitrides within the thickness range studied (33-87 /spl Aring/). In addition, stress-induced leakage current (SILC) does not monotonically increase when the dielectrics are aggressively scaled down to the ultra-thin regime. This "turn-around" effect of SILC can be explained using the trap-assisted tunneling model.<>

Keywords

MOS capacitors; dielectric thin films; electric breakdown; leakage currents; semiconductor device reliability; semiconductor process modelling; surface cleaning; tunnelling; 33 to 87 angstrom; MOS capacitors; N/sub 2/O; catastrophic breakdown; dielectric breakdown; dielectric integrity; reliability characteristics; stress-induced leakage current effects; surface preparation technique; trap-assisted tunneling model; two-step dip; ultra-thin oxides; ultra-thin oxynitrides; wafer-cleaning procedure; Design for quality; Dielectric substrates; Electron traps; Hafnium; Hydrogen; Leakage current; Passivation; Silicon; Surface cleaning; Tunneling;

fLanguage

English

Publisher

ieee

Conference_Titel

Electron Devices Meeting, 1994. IEDM '94. Technical Digest., International

Conference_Location

San Francisco, CA, USA

ISSN

0163-1918

Print_ISBN

0-7803-2111-1

Type

conf

DOI

10.1109/IEDM.1994.383338

Filename

383338