The evolution of hydrogen molecule formation in hydrogen-plasma-treated Czochralski silicon

The formation of H-2 molecules in voids/platelets and their evolution upon annealing were studied. Standard p- and n-type Czochralski (Cz) silicon wafers have been treated by a hydrogen plasma at 250 degreesC. After the plasma hydrogenation the samples were annealed at temperatures up to 600 degreesC in air. Investigations were done by Raman spectroscopy. H-2 did appear as nearly free molecules in the platelets/voids (Raman shift similar to 4150 cm(-1)), but not on the tetrahedral interstitial position in the Si lattice. The normalized Raman intensities of the H-2 vibration modes exhibited significant sensitivity to the annealing temperature for both p- and n-type Ct Si. These peculiarities can be explained by the evolution of the platelets during annealing. (C) 2001 Elsevier Science Ltd. All rights reserved.