microelectronics industry, the silicon chip size has been developed from 6 ", 8" to 12 ", while the wiring width has been reduced from 0.5um to 0.25um, 0.18um or even 0.13um. In the previous technical requirements, the target with 99.995% target purity can completely meet the process requirements of 0.35um IC, but now the target purity is required to 99.999% or even 99.9999% for the preparation of 0.18um line.

After a series of target processing, impurities in the target solid and oxygen and water vapor in the pores are the main pollution sources of deposited films. Because of the different uses, the requirements for different impurities are different for different targets. For example, the pure aluminum and aluminum alloy targets used in the semiconductor industry now have special requirements for alkali metal content and radioactive element content.

The density of the target is also one of the key performance indicators of the target. In order to reduce the porosity in the target solid and improve the performance of the sputtered film in the target technology, it is generally required that the target must have a high density. Because the main characteristic density of the target material has a great influence on the splash rate, and affects the electrical and optical properties of the film. The higher the target density is, the better the film performance is.

Then we will talk about the grain size and its distribution. Generally, the target material is polycrystalline structure, and the grain size can be from micrometer to millimeter. 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, while the thickness distribution of the film deposited by the target with small grain size difference (uniform distribution) is more uniform. A kind of