AVS 47th International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS-WeP

Paper PS-WeP29
Evaluation of the Spatial Density of Sputtered Particles with Monte Carlo Simulation

Wednesday, October 4, 2000, 11:00 am, Room Exhibit Hall C & D

Session: Poster Session
Presenter: T. Nakano, Seikei University, Japan
Authors: T. Nakano, Seikei University, Japan
S. Baba, Seikei University, Japan
Correspondent: Click to Email
We have developed a method to evaluate the spatial density of sputtered particles in the sputtering process using Monte Carlo simulation. With the simulation, the elapsed time T@sub p@ of the particles (~10@super 5@ of trials) staying in a certain spatial region is summed up. In the same simulation, the time T@sub s@ required to emit all the trial particles is also calculated, by comparing the simulated arrival number of particles at the substrate with the deposition rate in the actual experiment. The number of particles in the spatial region can be obtained by taking the ratio T@sub p@/T@sub s@, and the spatial density is calculated by dividing it with the volume of the region. For the accurate calculation of T@sub p@, we have applied the model of the particle transfer in the gas atoms of Maxwellian distribution, which has been used successfully for the high pressure sputtering.@footnote 1@ In the present report, the calculated spatial density of the sputtered Cu is applied to explain the intensity of the optical emission from Cu in the plasma, because we have observed a different behavior in the pressure dependence between the emission at 324.8 nm and the emission at 510.6 nm in our previous report@footnote 2@. For gas pressures of 2~20 Pa and the deposition rate of 0.1~0.2 nm/s, the spatial density of the Cu atoms is found to be 10@super 17@~10@super 19@ m@super -3@ near the target. The density increases with the increase of the Ar pressure. This high spatial density of Cu atoms results in the self-absorption of 324.8 emission by those atoms at the ground state, which makes the increase of 324.8 line less steeper than the 510.6 line at higher pressures. @FootnoteText@ @footnote 1@ T. Nakano, I. Mori and S. Baba, Appl. Surf. Sci. 113/114 pp.642 (1997) @footnote 2@ T. Nakano and S. Baba, Vacuum in press.