Pulsed laser deposition from solid and molten metals

Can particulates formation in general be avoided by using liquid targets, or only can particulates deposition be suppressed by choosing appropriate experimental circumstances? In order to answer this question, which is of general importance in pulsed laser deposition, we deposited indium, tin and bismuth films from the respective metal targets both in solid and liquid form, in vacuum. The substrates were held at room-temperature, in order to collect and preserve the droplets if formed. Ablating molten targets, the appearance of droplets of diameter exceeding microns can completely be eliminated. The particulates number density of indium and tin films decreased by two orders of magnitude as compared to the solid-target case. However, even in these cases, particulates formation could not be totally eliminated. The thickness distribution of the film material becomes broader when deposited from molten target. q1999 Elsevier Science B.V. All rights reserved.