The presence of droplets in pulsed laser deposition of aluminum with capillary ablation targets

It is shown that in pulsed laser deposition (PLD) reduction of unwanted dro plets can be achieved by the ablation of a capillary at grazing incidence a nd putting the deposition substrate behind the capillary. Capillaries made of pure aluminum were used in the described experiments and the diameter of the capillary was set equal to the beam waist diameter of the focused lase r beam. The deposition yield observed under these conditions on the rear su bstrate is about six times lower than the corresponding yield on the front substrate. Droplets are detected on both substrates, but on the rear substr ate, droplets larger than about 10 mu m are completely absent, and the abun dance of smaller droplets is about two times less. (C) 2000 Elsevier Scienc e B.V. All rights reserved.