Magnetron sputtering target used their advantages and disadvantag

Rectangular planar targets are characterized by simple structure, versatility, film uniformity and repeatability. But the disadvantage is the use of target material is low, typically about 20% [2] so. When the glow zone, the magnetic flux distribution of a target region is exhausted to a certain extent, will form a strip pits thinning target body, pit depth to a certain extent, the target can not continue to be used.
3.2 coaxial cylindrical magnetron sputtering target
Coaxial cylindrical magnetron sputtering target shown in Figure 4 [2], the magnetic field lines parallel to the target surface and perpendicular to the electric field E. Magnetic line with the target surface enclosed space is constrained plasma electron motion area. This region is an annular space, it can be seen from the figure, the coaxial cylindrical magnetron sputtering target has a plurality of annular spaces.
Coaxial cylindrical magnetron tungsten carbide plate shooting test has the advantage of a compact, relatively flat rectangular target target utilization high. The disadvantage is that the sputtering, the entire target surface into a plurality of brightness halo, glow not form a continuous strip, the large area of ​​the coated film, the film surface uniformity is poor, it is difficult to meet the requirementsRectangular planar target structure diagram shown in Figure 2 [1], the magnetic field parallel to the direction of the cathode target surface, forming an annular magnetic field and electric field E perpendicular. When the vacuum chamber filled with argon gas, it is ionized, the discharge generated by A + r ion bombardment cathode (target) surface. E1 secondary electrons by the magnetic field B, the Lorentz force, along a direction perpendicular to the magnetic field lines (Figure 3). These electronic motion path length The collision of gas molecules increases opportunities to increase the ionization probability of gas, thus increasing the sputtering rate.