We have studied three different H-2 molecules in crystalline silicon using
Raman scattering. The vibrational line at 3601 cm(-1) attributable to H-2 i
n Td site is observed both in n-type and p-type crystalline silicon. It is
suggested from the hydrogenation-temperature dependence that the charge sta
tes and the sites of atomic hydrogen affects the formation of this type of
H-2. H-2 in platelet observed at 4158 cm(-1) decreased in its intensity in
Si+-implanted silicon. A new vibrational line is detected at 3822 cm(-1) ,
and attributed to H-2 trapped by hydrogen-related defects such as multivaca
ncies produced by ion implantation.