Formation of TiN/TiSi2/p+-Si/n-Si by rapid thermal annealing (RTA) silicon implanted with boron through titanium

A low temperature method of fabricating conductive (3.5 Ω/ sq.) p
⁺
/n junction diodes possessing excellent
I-V
characteristics with reverse-bias leakage less than -3 nA.cm
^-2
at -5 V is described. Single crystal n-type 〈100〉 Si is implanted with 60 keV
¹¹
B
+
through 0.028-µm thick sputtered Ti film. Rapid thermal annealing (RTA) in an N
2
ambient simultaneously forms a 0.36-µm deep p
⁺
/n junction and a 0.063-µm thick bilayer of TiN and TiSi
2
with a resistivity of 22 µΩ.cm. The electrical properties of these diodes are not degraded by annealing for 30 min at 500°C, suggesting that the outer layer of TiN is an effective diffusion barrier between TiSi
2
and Al.