The energy-distributions of ions of 30 and 200 keV N+ and 110 keV Fe+ ions through cell models have been calculated with the Monte Carlo method. Energy depositions produced by both electrons and molecular vibration were also discussed.The calculations show that the thermal energy deposition is concentrated in a thin layer

for the implantation of 30 keV N+ ions with a dose of 1× 1015/cm2

an energy density of up to 2.55 ×105J/cm3 can be reached within a depth of less than 200nm.