The target material used in the data storage industry requires high purity, and impurities and pores must be minimized to avoid the generation of impurity particles during sputtering. The target material used for high-quality products requires that its crystal particle size must be small and uniform, and have no crystal orientation. Below, I will take you to see what are the requirements for the target material in the optical storage industry?

1. Purity

In practical applications, the purity of target materials varies according to different industries and requirements. However, overall, the higher the purity of the target material, the better the performance of the sputtered film. For example, in the optical storage industry, the purity of the target material is required to be greater than 3N5 or 4N

2. Impurity content

The target material serves as the cathode source in sputtering, and impurities in the solid and oxygen and water vapor in the pores are the main pollution sources for depositing thin films. In addition, there are special requirements for targets of different uses. Taking the optical storage industry as an example, the impurity content in sputtering targets must be controlled very low to ensure the quality of the coating.

3. Grain size and size distribution

Usually, the target material has a polycrystalline structure, with grain sizes ranging from micrometers to millimeters. For targets with the same composition, the sputtering rate of fine grain targets is faster than that of coarse grain targets. For targets with smaller grain size differences, the deposited film thickness will also be more uniform.

4. Compactness

In order to reduce porosity in the solid target material and improve film performance, it is generally required that the sputtering target material have a high density. The density of the target material mainly depends on the preparation process. The target material manufactured by melting and casting method can ensure that there are no pores inside the target material and the density is very high.