Electronic effect on crystallization growth velocities produced by charged dangling bonds in a-Si

Abstract
Ion implantation of electrically active dopants in silicon lowers the activation energy measured in crystallization growth velocity studies. Evidence indicates that this change is due to an electronic effect, arising from the charging of dangling bonds which produces a shift in the Fermi level on both sides of the amorphous-crystalline interface. The difference in the shifts of the Fermi levels in the bulk amorphous and crystalline Si is identified as being equal to the change in activation energy. We find the negatively and positively charged dangling bond states to be separated by approximately 0.35 eV, and roughly centered about midgap.