The TiN/TiSi2 bilayer formed on n(+)-p junction by rapid thermal annea
ling (RTA) process was investigated. The various thicknesses of titani
um him (10-80 nm) were sputtered on the n(+)Si substrate, then anneale
d by RTA at a temperature of 850 degrees C for 30 s in a N-2 ambient (
850 degrees C/30 s/N-2). Junction leakage current densities of the n()-p diodes with TiN/TiSi2 bilayers were about 10 nA/cm(2) for the init
ial Ti film thickness below 65 nm. The TiN/TiSi2 bilayer was used as a
diffusion barrier between Cu and n(+)Si. Leakage current density and
specific contact resistance measurements were performed on the Cu/TiN/
TiSi2/n(+)Si contact system after thermal stress on various temperatur
es (250-600 degrees C). The thermal stability temperature increasing w
ith initial Ti film thickness was found. The optimum diffusion barrier
for Cu/n(+)Si contact system was the sample with initial Ti film thic
kness 50 nm after RTA 850 degrees C/30 s/N-2. It possessed the TiN (20
nm)/TiSi2 (100 nm) bilayer and the thermal stability temperature up t
o 475 degrees C for the Cu/n(+)Si contact system. We also displayed cr
oss-section transmission electron microscopy and glancing angle incide
nt X-ray diffraction data at various sintering temperatures and studie
d the failure mechanism.