High density plasma deposition of device quality silicon nitride. II. Effects of thickness on the electrical properties

M. C. Hugon, F. Delmotte, B. Agius, E. A. Irene
1999 Journal of Vacuum Science & Technology B Microelectronics Processing and Phenomena  
Dielectric behavior of SiN x films, fabricated by microwave electron cyclotron resonance discharge, has been studied as a function of film thickness on the basis of the current-voltage and the capacitance-voltage characteristics. In the thickness range (20 nmϽdϽ80 nm), the resistivity and the critical field for SiN x were found not to be sensitive to the film thickness ͑d͒ and which was opposite to strong dependence of the dynamic dielectric constant ⑀ d on thickness. To explain the ⑀ d
more » ... ain the ⑀ d behavior as a function of d, a model based on trapped space charge effects is proposed. The dominant mode of electronic conduction, determined from J -E 1/2 curves and Arrhenius plots of leakage current, appears to be Poole-Frenkel emission only for thicker films (dϾ20 nm). Finally, the spatial profile of fixed charges reveals that SiN x /Si interface has a much greater concentration of defects than the bulk film.
doi:10.1116/1.591100 fatcat:mfbiptacgreevhqa4hvcdmrss4