EVALUATION OF (ETA(5)-C5H5)(CO)NI-IN[(CH2)(3)N(CH3)(2)](2) AS A SINGLE-MOLECULE PRECURSOR FOR OMCVD OF BINARY NI IN ALLOYS - DEPOSITION OF PHASE-PURE POLYCRYSTALLINE EPSILON-NIIN/
Ra. Fischer et al., EVALUATION OF (ETA(5)-C5H5)(CO)NI-IN[(CH2)(3)N(CH3)(2)](2) AS A SINGLE-MOLECULE PRECURSOR FOR OMCVD OF BINARY NI IN ALLOYS - DEPOSITION OF PHASE-PURE POLYCRYSTALLINE EPSILON-NIIN/, Chemistry of materials, 7(10), 1995, pp. 1863-1872
The volatile heterodinuclear organometallic compound (eta(5)-C5H5)(CO)
Ni-In[(CH2)(3)N(CH3)(2)](2) (1) has been shown to serve as a single-mo
lecule precursor to deposit Ni/In alloy thin films by thermal chemical
vapor deposition using either a horizontal hot-wall reactor in the ab
sence of carrier gases in vacuo or a vertical cold-wall reactor with t
he carrier gases N-2 and H-2. The metal ratios of the thin films depen
d on the substrate temperature. Nickel rich films were deposited below
250 degrees C. The 1:1 stoichiometry of the metals of the precursor c
ompound is perfectly retained above 350 degrees C. Typical growth rate
s were between 0.1 and 3 Angstrom s(-1). At low substrate temperatures
the cyclopentadienyl ligand is transferred from the nickel atom to th
e indium center during the film growth generating volatile and thermal
ly stable [(eta(5)C(5)H(5))In] which leaves the reaction zone. Other b
yproducts were mainly cyclopentadiene and unsaturated dimethylpropylam
ines, e.g., H2C=CHCH(2)NMe(2). The films were examined by SEM-EDX and
Auger electron spectroscopy and proved to be reasonably pure showing l
evels of C, O, and N below 1-2 atom % and exhibit specific resistiviti
es in the range of 250(+50) mu Omega cm. Films grown on various substr
ates (quartz, GaAs, InP) were structurally characterized by X-ray diff
raction showing the hexagonal epsilon-NiIn as the only detectable crys
talline phase. Plasma enhanced MOCVD experiments were also performed a
nd expectedly showed a much lower selectivity of the decomposition che
mistry of the precursor. Ni/In microstructures (e.g., squares of 200 m
u m side length, a line width of 25 mu m and a line height of 12 mu m)
were drawn by photothermic laser direct writing on Al2O3 substrates.