T. Kaizuka et al., CONFORMAL CHEMICAL-VAPOR-DEPOSITION TIN(111) FILM FORMATION AS AN UNDERLAYER OF AL FOR HIGHLY RELIABLE INTERCONNECTS, JPN J A P 1, 33(1B), 1994, pp. 470-474
Chemical vapor deposition (CVD) TiN film having the (111) preferred or
ientation and conformal step coverage was developed for the first time
. The key processes are predeposition of the Ti(002) layer before the
CVD TiN film deposition and optimization of the flow rate of reactants
: TiCl4, NH3 and H-2. Growth of (111) crystal plane seems to be induce
d due to the lattice matching of crystal plane of the Ti film. On the
other hand, conformal step coverage is obtained by using a lower flow
rate of NH3, resulting in the surface-limited chemical reaction. It wa
s also demonstrated that both sputtering and CVD Al, deposited on the
CVD TiN having stronger (111) orientation, showed stronger(111) orient
ation which is advantageous for obtaining high electromigration (EM) r
esistance. Furthermore, simultaneous contact hole filling and intercon
nects formation using CVD Al/CVD TiN stacked film are successfully dem
onstrated.