Laser chemical vapor deposition (LCVD) of low resistivity copper from
Cu(hfac)tmvs (copper(I)-hexafluoroacetylacetonate trimethylvinylsilane
) is presented. The deposition was performed on Si3N4 and SiO2 passiva
ted ICs. The deposition of Cu lines was carried out by a focused Ar+ l
aser beam. The deposition speed and the laser power were varied in the
range of 24 to 400 mu m/s and 40 to 1200 mW, respectively. The precur
sor gas partial pressure was 0.3 mbar buffered in 10 mbar He or H-2. T
he morphology of the deposited lines was investigated by AFM, optical
microscopy and LIMA. The LIMA analysis showed the deposited copper sur
face was contaminated but the contamination level decreased when the l
ayer was depth profiled. The electrical resistivity was found to be 3.
7 mu Omega cm as determined by four point probe measurement. The effec
t of the laser beam focus location on the substrate surface is describ
ed. Low resistivity laser direct-write Cu lines were utilised in speci
fic IC customisation cases.