**7. Conclusions**

each target will be performed at the same frequency as in the case of one target. Each target must have its own diaphragm, moving simultaneously with the target at a velocity *V*=const/*r*. Suppose we are going to use *N* targets to deposit a film on a substrate with a radius *R*. Obviously, the targets must be located with respect to each other and with respect to the substrate in such a way as, having started deposition from all targets simultaneously and moving each target at a velocity *V* = const/*r*, to deposit a film on the entire substrate surface and finish deposition from all targets simultaneously. It can be shown that, to deposit a film of uniform thickness on a substrate of radius *R*, the *N* targets must be initially located so as to

170 Applications of Laser Ablation - Thin Film Deposition, Nanomaterial Synthesis and Surface Modification

intersection of the perpendicular dropped from the first target with the substrate plane.

**Figure 23.** Moving ribbon, *N* targets: 1, ribbon; 2, plasma torch; 3, target. (a) N times acceleration of sputtering process,

We can use more than one target also in the mask method (paragraph 3.2.3). Certainly, we can use more than one target as described in paragraph 5 designs for deposition on a moving ribbon. Using *N* targets, we can accelerate sputtering process *N* times (**Figure 23a**), or obtain

‐1/2 from the substrate center (**Figure 22**) to the point of

provide a distance *Xl*

**Figure 22.** Moving *N* targets.

(b) deposition on N time wider tape.

a film on the tape which is *N* times wider (**Figure 23b**).

(*t0*) = *R*(*l*‐1)1/2(*N*)

We believe that the main result of the present work is the proposal and realization of a simple and reliable method of obtaining thickness‐ and composition‐uniform thin films on large areas, with the use of laser deposition. The mask method of deposition on a rotating substrate can be used at any standard arrangement. The size of the obtained films and achieved degree of the thickness uniformity are not limiting. In any specific case where the permissible degree of the thickness nonuniformity is given, one may calculate the slit configuration providing the maximal rate of the deposition.

The new device for laser deposition of thin films is suggested, substantiated, and experimen‐ tally tested, which simply and cardinally overcomes the main drawback of the PLD method, namely a low coefficient of the target material utilization efficiency. Taking into account the advantages of laser deposition as compared to other methods of the manufacture of thin films, we hope that the proposed methods will be used in elaboration of new technologies in microelectronics and optical industry.

A more detailed description of the proposed methods can be found in patents [13–20]. Apart from PLD, the proposed methods are applicable to all methods of deposition from a point source.
