This work investigates the Cu diffusion in SiCOH low dielectric constant films

treated by O2 plasma. By capacitance–voltage and current-voltage measurement,

and thermal stress analysis, it was found that the O2 plasma surface treatment of

SiCOH films can lead to the decrease of flat-band voltage shift ΔVFB, the increase

of activation energy Ea, and the decrease of leakage current. The small ΔVFB and

lower leakage current indicate the weak Cu diffusion. The increase of active energy

means the reducing of fast Cu ions surface diffusion through the interconnected

pores structure of the film. Hence, the Cu diffusion in SiCOH films can be reduced

by O2 plasma treatment. By FTIR and AFM analysis on the bonding configuration

and microstructure, the reduce of Cu diffusion was related to the increase of Si-O

cages and networks, which made more open pores sealed at the surface of SiCOH

films.

Reducing Cu Diffusion in SiCOH Low-K Films by O2 Plasma Treatment. J.Yuan,

C.Ye, Z.Xing, Y.Xu, Z.Ning: Microelectronic Engineering, 2009, 86[10], 2119-

122