The importance of gas scattering processes on the stoichiometry deviations of laser deposited films

Monte Carlo simulation of pulsed laser ablation from two-component target into diluted ambient gas

“…The results obtained in the present study are in agreement with several experimental findings, 8,19,[26][27][28] where the broadening of the angular distributions and the decrease of the deposition rate due to the scattering processes in the ambient gas were observed. For example, Lichtenwalner et al 8 investigated the ablated flux characteristics of PZT, LCS and MgO ceramic targets as a function of chamber pressure for different gases ͑O 2 and noble gases͒.…”

“…The effects of the background gas on the deposition process were considered in a number of papers. The experimental results on ablation in the presence of ambient gas 8,[18][19][20] revealed the dependence of the deposition rate on the ambient gas parameters. The comparison between the results obtained for the deposition in inert and reactive atmospheres ensured that part of these effects is not chemical in nature.…”

“…Under these conditions, the influence of the ambient gas on the film thickness profile has not been theoretically investigated sufficiently and these effects are not yet clear. For instance, several papers report broadening of the angular distribution of the ablated particles as a result of scattering processes in the background gas, 8,19,[26][27][28] while the focusing effect was observed by other authors. 21,29,30 The increase of the backscattering of particles is also an important effect of ambient gas that can influence the deposition process.…”

Stoichiometry issues in pulsed-laser deposition of alloys grown from multicomponent targets

“…We are dealing with multiple species which may have different angular distributions in the plume [15]. This can be due to difference in the mass of the species or differences in the charge states of the species [16], or due to the rapid expansion of the plume into the vacuum [17].…”

Tailoring of stoichiometry and band-tail emission in PLD a-SiC thin films by varying He deposition pressure

“…The films grown by PLD in vacuum do not necessarily preserve the target stoichiometry [34]. Venkatesan et al [35] and Gonzalo et al [36] have demonstrated that the interaction of the ablated species in the Laser Produced Plasma (LPP) plume of the target material with a reactive or nonreactive background gas improves the morphology and could also modify the film stoichiometry. In PLD the LPP plume moves forward having a maximum particle density along the normal to the target.…”