EFFECT OF TEMPERATURE ON THE BULK ATOMIC RELOCATION IN LOW-ENERGY COLLISION CASCADES IN SILICON - A MOLECULAR-DYNAMICS STUDY

The production of damage in a Si lattice by internally starting 100 eV self-recoils has been studied using a MD simulation. Different initia l lattice temperatures below the Debye temperature for Si have been co nsidered. The number of stable atomic displacements and the amount of atomic mixing increase with the initial target temperature. The increa se with temperature of atomic mixing is nonlinear -appreciable changes lake place between 300 and 500 K, while the difference between the am ount of mixing corresponding to 0 and 300 K is negligibly small. The s ize of the cascade zone in which stable atomic displacements occur dou bles itself for temperature changes between 0 and 300 K, with a value for 500 K lying in between. This nonmonotonic variation with the initi al target temperature of the size of the cascade zone may have its ori gin in the correlation between the initial direction of motion of the starting recoil and the directions of thermal velocities of the neighb ouring atoms around this recoil.