Titanium target

Purity is one of the main performance indicators of the target, because the purity of the target has a great impact on the performance of the film.

Main performance requirements of target materials

The main performance requirements of the target material are as follows:

purity

Purity is one of the main performance indicators of the target, because the purity of the target has a great impact on the performance of the film. However, in practical application, the purity requirements of target materials are not the same. For example, with the rapid development of microelectronics industry, the size of silicon wafer has increased from 6 "and 8" to 12 ", while the wiring width has decreased from 0.5um to 0.25um, 0.18um or even 0.13um. In the past, 99.995% target purity can meet the process requirements of 0.35um IC, while 99.999% or even 99.9999% target purity is required for the preparation of 0.18um line.

Impurity content

Impurities in the target solid and oxygen and water vapor in the pores are the main pollution sources. Different target materials have different requirements for different impurity contents. For example, pure aluminum and aluminum alloy targets for semiconductor industry have special requirements for alkali metal content and radioactive element content.

density

In order to reduce the pores in the target and improve the properties of sputtered films, the target with high density is usually required. The density of the target not only affects the sputtering rate, but also affects the electrical and optical properties of the films. The higher the density of the target, the better the performance of the film. In addition, by increasing the density and strength of the target, the target can better withstand the thermal stress in the sputtering process. Density is also one of the key performance indicators of target materials.

Grain size and its distribution

Generally, the target material is polycrystalline structure, and the grain size can range from micron 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, and the thickness distribution of the film deposited by sputtering is more uniform for the target with small grain size difference (uniform distribution).