Purity>>
Purity is one of the main performance indexes of the target material, because the purity of the target material has a great influence on the performance of the film. However, in practical applications, the purity requirements for target materials are not the same.For example, with the rapid development of the microelectronics industry, the size of silicon wafer has developed from 6 "and 8" to 12 ", and the wiring width has been reduced from 0.5um to 0.25um,0.18um or even 0.13um. Previously, the purity of target material of 99.995% can meet the technical requirements of 0.35umIC, while the purity of target material for the preparation of 0.18um line requires 99.999% or even 99.9999%.

Impurities>>
Impurities in target and oxygen and water vapor in gas hole are the main pollution sources of deposited films. Different applications have different requirements for different impurities.For example, pure aluminum and aluminum alloy targets used in the semiconductor industry have special requirements for alkali metal content and radioactive element content.

Density>>
In order to reduce the porosity of target solid and improve the performance of sputtering film, high density of target material is usually required. The target density affects not only the sputtering rate but also the electrical and optical properties of the films.The higher the target density, the better the film performance.In addition, increasing the density and strength of the target enables the target to better withstand the thermal stress in the process of sputtering. Density is also one of the key performance indexes of target material.

Grain Size>>

The target material is usually polycrystalline in size from micron to millimetre. For the same target, the sputtering rate of the target with small grain size is faster than that of the target with large grain size.The films deposited by target sputtering with less grain size difference (uniform distribution) have more uniform thickness distribution.