How to use ZnO or Zn powder to make large diameter sputtering target?
How to make a sputtering target?
There are two main ways to make a sputtering target. One is casting. The alloy raw material of a certain distribution ratio is melted, and the alloy solution is poured into a mold to form an ingot, and finally a target material is machined, and the casting method is smelted and cast in a vacuum. The other is powder metallurgy. The alloy material which has a certain distribution ratio is melted, cast into an ingot and then pulverized, and the powder formed by pulverization is isostatically pressed and then sintered at a high temperature to finally form a target.
Is it possible to make a sputtering target by ZnO or Zn Powder?
Firstly, you have to know that zinc oxide sputtering targets made from ZnO powders are not stable. On one hand, ZnO powders are costly; on the other hand, large diameter target are not easy to prepare. And after some sputtering runs, oxide targets would become non stoichiometric, and similarly with PLD technique, after some ablations the target stoichiometry changes. You have to scrape the targets, and then re-use them.
If you try to prepare such large diameter target by pressing ZnO powders, you need a good hydraulic press to compact the powders, an appropriate die, and then sinter the compacted powder disc.
Finally you need a good furnace with a large flat zone, otherwise the sintered disc will warp, and you will be unable to get flat sintered discs that can be used as sputtering targets.
Moreover, such oxide target will not be reiable in the long run, and they may ten to crack at high rf powers, unless you bond them to a copper blanking plate with specially thermally and electrically conducting cements.
Compared with ZnO, Zn sputtering target discs of 10 to 15 cm diameter are relatively inexpensive, and will last a much longer time, and you can do reactive sputtering easily, to make ZnO films.
How to use Zn powder to make large diameter sputtering target?
As I mentioned before, casting and powder metallurgy are the two main ways to make a sputtering target. If the raw material is Zn powder, then the latter method is preferred. You can easily purchase 2mm thick Zn metal plates of high purity from any standard chemical company, and get them machined into circular discs of required diameter, and use them as targets. Using Zn targets is more reliable, long standing, and can be sputtered at high powers to get high deposition rates.
In the end, I have to tell you that making a sputtering target, especially of high quality, is not easy and can be costly. In most cases, it is better to purchase sputtering target directly from trustable sputtering target manufacturer. SAM Sputter Target is a global sputtering target manufacturing company. We provide metals, alloys, oxides and ceramic materials of high quality and at a competitive price. Please visit https://www.sputtertargets.net/ for more information.