Jc. Chiou et al., THE PROCESSING WINDOWS FOR SELECTIVE COPPER CHEMICAL-VAPOR-DEPOSITIONFROM CU(HEXAFLUOROACETYLACETONATE)TRIMETHYLVINYLSILANE, Journal of the Electrochemical Society, 142(1), 1995, pp. 177-182
To identify the processing tolerance for the selective Cu chemical vap
or deposition (Cu CVD) the processing windows were constructed with re
spect to deposition pressure and substrate temperature over thermally
grown SiO2 vs. various conducting substrates of W, CoSi2, TiN, TiW, an
d Al. It is found that the width of selective deposition window decrea
ses as the deposition pressure is increased, and no selective Cu depos
ition can be obtained as the deposition pressure exceeds 120 mTorr. Th
e lowest temperatures for Cu CVD on various SiO2 substrates including
thermally grown, BPSG, TEOS, and PECVD SiO2 were determined so that pr
ocessing windows for selective Cu deposition on Variously patterned wa
fers can be constructed. The selective Cu deposition was also conducte
d on patterned substrates with submicrometer feature sizes using the P
ECVD SiO, as the interlayer dielectric. The nucleation of Cu on the Si
O2 surface obviously acts as the major limitation for achieving select
ive Cu CVD. We postulate that the Cu containing adspecies, Cu(hfac), o
n the insulating SiO2 surface may combine by surface diffusion, and th
ese assembled adspecies then disproportionate by exchanging electrons
with each other rather than transferring electrons through the substra
te.