Ion implantation model considering crystal structure effects

An ion implantation model for crystalline targets is proposed. The model is based on the Monte Carlo method. Ion behavior is determined by directly referring to three-dimensional crystal structure data. Both channeling and dechanneling can be well simulated by modeling many-body scattering with lattice atoms and introducing atom thermal vibration effects. This model is used to simulate low-energy boron implantation in crystal silicon. Significant boron distribution tail spreading is predicted due to subchanneling effects, even if the ion beam is tilted and/or the crystal surface is covered with amorphous layers. These predictions agree with experimental data. Amorphization effects on two-dimensional boron distribution were also investigated. It was predicted that locally insufficient preamorphization causes marked lateral spreading of boron