H. Haberland et al., THIN-FILMS FROM ENERGETIC CLUSTER-IMPACT - EXPERIMENT AND MOLECULAR-DYNAMICS SIMULATIONS, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 80-1, 1993, pp. 1320-1323
Thin film formation by energetic metal cluster ions (Al, Ti, Cu, Mo, a
nd Ta) is studied. The clusters are electrically accelerated, separate
d from the neutral ones, and deposited on a surface. If the kinetic en
ergy is higher than about 5 keV for a cluster of about 1000 atoms, hig
hly reflecting, strongly adhering thin films are formed on room temper
ature substrates. The film morphology does not fit the structure zone
model of Movchan, Demchishin and Thornton. Langevin molecular dynamics
simulations give the following physical picture: a tiny, very high te
mperature spot is formed at each impact. This anneals the area around
the impact zone and gives rise to near epitaxial growth. The main adva
ntage of the method seems to be that dense films without columnar void
s can be produced on room temperature substrates. The abbreviation ECI
for energetic cluster impact is proposed for this method.