Integration methodology of chemical vapor deposition TiN, chemical vapor deposition W and W chemical mechanical planarization for sub-quarter micron process application
J. Wu et al., Integration methodology of chemical vapor deposition TiN, chemical vapor deposition W and W chemical mechanical planarization for sub-quarter micron process application, J VAC SCI B, 17(5), 1999, pp. 2300-2305
Chemical vapor deposition (CVD) W plugs have been widely used for device me
tallization with excellent conformity in small contacts/vias with high aspe
ct ratio [J. E. J. Schmitz, Chemical Vapor Deposition of Tungsten and Tungs
ten Silicides (Noyes, 1991)]. However, some unexpected plug fill such as pl
ug loss and key hole exposing post tungsten chemical mechanical planarizati
on (WCMP) still happened while going to smaller plug size and using metalor
ganic chemical vapor deposition (MOCVD) TiN barrier. In this study, MOCVD T
iN and CVD W fill followed by WCMP for plug metallization were investigated
. Extensive analysis had been conducted on various types of defective W plu
gs. Organic contaminants (hydrocarbon by-products) in MOCVD TiN deposition
would prevent W deposition taking place inside the plug. For W wise, lower
process temperature, carefully adjusted WF6/SiH4 and WF6/H-2 partial pressu
re ratios had demonstrated better plug fill and electrical performance [T.
E Clark et al., J. Vac. Sci. Technol. B 9, 1478 (1991)]. In the WCMP approa
ch, the effects of different oxidizer concentration in slurry were characte
rized. Eliminating the seam formation during the CVD W process can help avo
id slurry attack in WCMP. The optimized integration scheme of MOCVD TiN bar
rier, CVD W, and WCMP was successfully achieved and is applied on 0.20 mu m
Logic production. (C) 1999 American Vacuum Society. [S0734-211X(99)05705-4
].