Instability trade-off of inter-layer or inter-metal dielectrics formation with low-k dielectrics on active and field device´s characteristics

Author

Chen, M.J. ; Shih, J.R. ; Yu, K.F. ; Hsieh, C.C. ; Sung, W.L. ; Lin, F.S. ; Chu, L.H. ; Shiue, R.Y. ; Peng, Y.K. ; Yue, J.T.

Author_Institution

Reliability Assurance Dept., Taiwan Semicond. Manuf. Co., Hsin-Chu, Taiwan

fYear

2001

fDate

2001

Firstpage

12

Lastpage

15

Abstract

The effects of back end of line (BEOL) processing with low dielectric constant (low-k) materials on active and field device performances have been studied. The study reveals: (1) there is SPICE model uncertainty because I_dsat increases as more metal layers are added; (2) low-k dielectrics can enhance this I_dsat increase; and (3) NMOSFET hot carrier lifetime and PMOSFET V_t stability are degraded. These effects are attributed to the BEOL-induced hydrogen generation and passivation with gate oxide dangling bonds, which are primarily created in the contact etching process. The modified process involves pure hydrogen alloy after metal-1 formation, which ensures the same device performance at metal-1 and at the final metal layer. In addition, the alloy can reduce the inverse narrow width effect and field isolation leakage currents

Keywords

CMOS integrated circuits; MOSFET; SPICE; carrier lifetime; circuit stability; dangling bonds; dielectric thin films; hot carriers; integrated circuit interconnections; integrated circuit metallisation; integrated circuit modelling; integrated circuit reliability; leakage currents; passivation; permittivity; plasma materials processing; sputter etching; BEOL processing; BEOL-induced hydrogen generation; H₂; NMOSFET hot carrier lifetime; PMOSFET threshold voltage stability; SPICE model uncertainty; SiO₂; active device characteristics; back end of line processing; contact etching process; device performance; drain saturation current; field device characteristics; field device performance; field isolation leakage currents; final metal layer; gate oxide dangling bonds; hydrogen alloy; instability trade-off; inter-layer dielectrics formation; inter-metal dielectrics formation; inverse narrow width effect; low dielectric constant materials; low-k dielectrics; low-k materials; metal layers; metal-1 formation; passivation; Degradation; Dielectric constant; Dielectric materials; Hot carriers; Hydrogen; MOSFET circuits; Passivation; SPICE; Stability; Uncertainty;

fLanguage

English

Publisher

ieee

Conference_Titel

Plasma- and Process-Induced Damage, 2001 6th International Symposium on

Conference_Location

Monterey, CA

Print_ISBN

0-9651577-5-X

Type

conf

DOI

10.1109/PPID.2001.929967

Filename

929967