PROGRAM SUMMARY
Title of program:
SPATS
Catalogue identifier:
ADKN
Ref. in CPC:
120(1999)238
Distribution format: uuencoded compressed tar file
Operating system: Linux (RedHat v. 4.0), Solaris v. 5.6
High speed store required:
1640K words
Number of bits in a word:
32
Number of lines in distributed program, including test data, etc:
7156
Programming language used: C++
Computer: IBM PC
Nature of physical problem:
Simulation of the transport of neutral sputtered particles during
magnetron sputter deposition. Sputtered particles, that have an initial
energy of several eV, are scattered by collisions with inert gas atoms
and their energy and direction is affected before arriving to a surface.
This process is dependent on system geometry, pressure, etc. The
program provides information about spatial distribution of the fluxes
towards surfaces in the chamber, density of sputtered particles in the
glow discharge, and angular and energy distribution of the flux arriving
to a substrate surface. These are crucial parameters for understanding
of the film growth process.
Method of solution
Monte Carlo simulation of the flight of neutral particle through an
inert gas is used. The collisions are modelled by means of
Lennard-Jones potential, Biersack's potential, or a binary hard sphere
approximation with energy dependent collision cross section. Initial
random velocity and direction of the sputtered particles are set
according to the distributions predicted by the collisional cascade
sputtering model [1] or by TRIM [2-4] simulation results.
Restrictions on the complexity of the problem
The influence of the sputtering process on the gas such as heating and
rarefaction is not taken into account.
Typical running time
For 0.13 Pa (1 mTorr) argon gas pressure and 10**6 generated particles
8 minutes of CPU time is used on Sun Ultrasparc computer.
References
[1] P. Sigmund, Phys. Rev. (1969) 383-416.
[2] J.F. Zieglier (IBM Research, Yorktown, NY 10598, USA, 1997).
[3] J.P. Ziegler, J.P. Biersack, U. Littmark, The Stopping and Range of
Ions in Solids (Pergamon Press, New York, 1985).
[4] W. Moller, W. Eckstein, J.P. Biersack, Comput. Phys. Commun.
51 (1988) 355.