RECRYSTALLIZATION OF A PLANAR AMORPHOUS-CRYSTALLINE INTERFACE IN SILICON BY LOW-ENERGY RECOILS - A MOLECULAR-DYNAMICS STUDY

We discuss the motion of an amorphous-crystalline interface in silicon induced by low energy recoils. We employ molecular dynamics simulation with the Stillinger-Weber interatomic potential for silicon. The temperature of the substrate in these simulations was 250 K. Our results show that when 15 or 20 eV recoils are initiated from the amorphous side of the interface, the crystal regrows by solid-phase epitaxy. On the other hand, no interface motion was detected for 15 eV recoils launched from the crystalline side, and damage accumulation resulted when the recoil energy was set to 20 eV. The efficiency of recrystallization for this process is 0.67, for both 20 and 15 eV recoils. That is, approximately two silicon atoms transform from the amorphous to the crystalline phase per every three incident recoils. The calculated threshold energy required to produce a stable defect in silicon was found to be substantially lower in an amorphous matrix than in a crystalline lattice. © 1995 American Institute of Physics.