The formation of H molecules in voids/platelets, and their evolution during annealing, were studied. Standard p-type and n-type Czochralski wafers were exposed to a H plasma at 250C. The samples were then annealed at up to 600C in air, and investigated using Raman spectroscopy. It was found that H2 appeared as nearly-free molecules in platelets/voids, but not at tetrahedral interstitial positions in the lattice. The normalized Raman intensities of the H2 vibrational modes exhibited a significant sensitivity to the annealing temperature in both p-type and n-type samples. This was explained in terms of evolution of the platelets during annealing.

The Evolution of Hydrogen Molecule Formation in Hydrogen Plasma-Treated Czochralski Silicon. R.Job, A.G.Ulyashin, W.R.Fahrner: Materials Science in Semiconductor Processing, 2001, 4[1-3], 257-60