purity
Purity is one of the main performance index of the target, because of the great influence of the purity of the film's performance target. But in the practical application, the purity of the target requirements are not the same. For example, with the rapid development of microelectronics industry, the wafer size by 6 ", 8" to 12 ", and the wiring width decreases from 0.5um to 0.25um, 0.18um and 0.13um, 99.995% of the target before the purity can meet the requirements of 0.35umIC process, and the preparation of 0.18um line to the target of 99.999% or even 99.9999% pure.
Impurity content
The target of solid impurities and pores in oxygen and water vapor is the main pollution source of the deposited films. The target of different uses of different impurity content requirements are also different. For example, pure aluminum and Aluminum Alloy target for semiconductor industry, have special requirements on the content of alkali metals and radioactive elements.
density
In order to reduce the air target in solids, improve the performance of the sputtered films, usually require the target with a higher density. The target density not only affects the sputtering rate, but also affects the electrical and optical properties of the films. The target density is high, the better the performance of the film. In addition, to improve the target density and intensity of the target are better able to withstand the thermal stress in the sputtering process. One of the key performance index is the target density