What is the working principle of sputtering target?

Sputtering target working principle  

Sputtering is one of the main technology of preparation of thin film materials, which makes use of the ion, ion source through accelerating gathered in a vacuum, and the formation of a high speed can ion beam, the bombardment of solid surface, ions and solid surface atomic momentum exchange, from solid surface atomic solid and deposition in the basal surface, as the solid bombarded sputtering target materials.

The components of sputtering target material

The target material is welded by "target blank" and "backplane".  

(1) The target blank is the target material of high speed ion beam bombardment, which belongs to the core part of sputtering target material, and involves the adjustment of high purity metal and grain orientation.  In the process of sputtering coating, after the target is impacted by ions, its surface atoms are sputtered out and deposited on the substrate to form electronic films.  

(2) the backplane mainly plays the role of fixing sputtering target material, involving welding process.  Because of the low strength of high-purity metal, the sputtering target needs to be installed in a special machine to complete the sputtering process.  The machine is in a high-voltage and high-vacuum environment, so the sputtering target blank of ultra-high purity metal needs to be joined with the backplane through different welding processes, and the backplane needs to have good electrical and thermal conductivity.  

Sputtering target coating process

The main coating processes are physical vapor deposition (PVD) and chemical vapor deposition (CVD).  

(1) PVD technology is the mainstream coating method at present, in which the sputtering process is widely used in semiconductor, display panel.  PVD technology is divided into vacuum evaporation, spatter plating and ion plating.  The three methods have their own advantages and disadvantages: the vacuum evaporation method has no limitation on the substrate quality;  The properties and uniformity of spatter film are better than that of steam film.  Ion plating method has strong wrapping ability and simplified cleaning process, but it affects the coating quality at high power.  The choice of different methods mainly depends on the product use and application scenario.  

(2) CVD technology mainly generates films through chemical reactions.  One or more gas phase compounds or elements containing film elements are introduced into the reaction chamber at high temperature, and films are generated by chemical reactions on the substrate surface.