Titanium target
发布时间：2019-06-12
Main performance requirements of target material:
purity
Purity is one of the main performance indicators 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 of target materials are different. For example, with the rapid development of microelectronics industry, the size of silicon wafer has been developed from 6","8"to 12". The wiring width has been reduced from 0.5um to 0.25um, 0.18um or even 0.13um. The former 99.995% target purity can meet the process requirements of 0.35umIC, while the preparation of 0.18um wire requires 99.999% or even 99.9999% of the target purity.
Impurity content
Impurities in target solids and oxygen and water in stomata are the main pollution sources of thin films deposited. Targets for different purposes have different requirements for different impurity contents. For example, pure aluminium and aluminium alloy targets used in semiconductor industry have special requirements for the content of alkali metals and radioactive elements.
density
In order to reduce the porosity in the solid of the target and improve the performance of the sputtered film, it is usually required that the target has a high density. The target density not only affects the sputtering rate, but also affects the electrical and optical properties of the films. The higher the target density, the better the properties of the films. In addition, increasing the density and strength of the target can make the target better withstand the thermal stress in the sputtering process. Density is also one of the key performance indicators of target materials.
Grain Size and Grain Size Distribution
Usually, the target material is polycrystalline, and the grain size can range from micron to millimeter. For the same target, the sputtering rate of the target with fine grain is faster than that of the target with coarse grain, and the thickness distribution of the film deposited by the target with small grain size difference (even distribution) is more uniform.
