First, the basic performance requirements of titanium target material
① Purity: as one of the main performance indicators of the target material, the purity of the film has a crucial impact on the performance. In practice, the purity of the titanium target material requirements varies according to the industry. For example, in the microelectronics industry, with the increasing size of silicon wafers and the decreasing width of wiring, the requirements for target purity are also increasing. Previously, 99.995% target purity could meet the process requirements of 0.35umIC, but now the preparation of 0.18um lines requires a target purity of 99.999% or even 99.9999%.
② impurity content: impurities in the target solids and pores in the oxygen, water, and gas are the main sources of contamination of the deposited film. Therefore, different uses of the target material on the impurity content requirements are different. For example, pure aluminum and aluminum alloy targets used in the semiconductor industry, the alkali metal content, and radioactive element content have special requirements.
③ Density: In order to reduce the pores in the target solid and improve the performance of sputtered film, the target is usually required to have a high density. The density of the target not only affects the sputtering rate but also affects the electrical and optical properties of the film. In addition, increasing the density and strength of the target material also allows it to better withstand the thermal stresses of the sputtering process. Therefore, density is also one of the key performance indicators of target materials.
④Grain size and grain size distribution: titanium target purity is usually polycrystalline in structure, and the grain size can range from micrometers to millimeters. For the same target, the sputtering rate of the target with fine grains is usually faster than that of the target with large grains; and the thickness distribution of the film deposited by sputtering of the target with a small difference in grain size (uniform distribution) is more uniform.
Second, different industries on the purity requirements of titanium targets
① Integrated circuits in the use of titanium targets: integrated circuits on the titanium target purity requirements are extremely high, and usually need to be greater than 99.995% to ensure the performance and stability of the film.
② Flat-panel displays used in titanium targets: flat-panel displays, including liquid crystal displays, plasma displays, electroluminescent displays, and field emission displays. These displays often use sputtering coating technology to deposit thin films in the manufacturing process. Among them, titanium target is one of the important sputtering targets, and its purity usually needs to be more than 99.9%.
In addition, titanium targets can be widely used in electronics, information industry, home decoration, automotive glass manufacturing and other high-tech fields. In these industries, titanium targets are mainly used for coating integrated circuits, flat panels and other components of the surface panel displays, or as decorative and glass coating. By optimizing the properties and purity of titanium targets, we can meet the needs of different industries for film performance and stability.
