Formation of Hydrogen Molecules in n-Type Silicon

We have investigated hydrogen molecules ( H2) formed in heavily doped n-type silicon by remote hydrogen atom treatment. We measure the Raman lines of H2 as a function of the substrate temperature during hydrogen atom treatment. A broad vibrational Raman line of H2 can be clearly observed at around 4158 cm-1 for substrate temperatures between 250 and 500° C, indicating that hydrogen exists in molecular form in crystalline silicon. The vibrational Raman line of H2 has a maximum intensity for a substrate temperature of 400° C. An isotope shift is also detected at around 2990 cm-1 in silicon treated with deuterium atoms at 400° C.