Thermal stability of undoped polycrystalline silicon layers on antimony and boron-doped substrates

Peer-reviewed article not indexed in WoS or Scopus

en

The structure of as-deposited and annealed polycrystalline silicon layers has been investigated by scanning electron microscopy and x-ray diffraction. The structure of intentionally undoped layers prepared by low pressure chemical vapor deposition at a temperature of 640 C was found to be stable upon annealing at temperatures lower than about 900 C. On the other hand, primary recrystallization of the layers has been observed during annealing at temperatures in the range of 900 to 1150 C. Isochronal annealing revealed the activation energy for the primary recrystallization of undoped layers as 0.6 eV. The activation energy for diffusion of silicon self-interstitials along the grain boundaries was calculated to be 2.2 eV. The difference in grain-growth process was observed for the undoped layers grown either (i) on lightly boron-doped substrate or (ii) on the substrate heavily doped with antimony. The different grain-growth mechanism was found to be a consequence of antimony diffusion into the polycrystalline layer.

Chemical vapor deposition; Structural properties; Polycrystalline silicon; Recrystallization; Grain growth

2010-05-03

0040-6090

Thin Solid Films

518

14

4052–4057

6