The main performance requirements of targets
Purity
Purity is one of the main performance index of the target, because the purity of target has great influence on the film's performance. But in the practical application, the purity requirements of target are not the same. For example, with the rapid development of the microelectronics industry, silicon wafer size developed from 6, 8 to 12, which the wiring width is reduced from 0.5um to 0.25um, or 0.18um even 0.13um. In the past, the target with 99.995% purity can meet requirements of the process of 0.35umIC, while the requirement of 0.18um lines to the purity of target is 99.999% or even 99.9999%.
Impurity content
The impurities of target solid and the oxygen and water vapor of target pores are the main pollution source of the deposited films. The different uses of the Zr target are also different to the requirements of different impurity content. For example, pure aluminum and aluminum alloy target used in the semiconductor industry have special requirements to content of alkali metal and radioactive elements.
Grain size and grain size distribution
The target usually is polycrystalline structure, the grain size can be measured from micron to millimeter. For the same kind of target, the sputtering rate of target of fine grain size is faster than the coarse grain target sputtering rate, the thickness distributions of thin film of target sputtering with small grain size difference is more uniform.
Purity is one of the main performance index of the target, because the purity of target has great influence on the film's performance. But in the practical application, the purity requirements of target are not the same. For example, with the rapid development of the microelectronics industry, silicon wafer size developed from 6, 8 to 12, which the wiring width is reduced from 0.5um to 0.25um, or 0.18um even 0.13um. In the past, the target with 99.995% purity can meet requirements of the process of 0.35umIC, while the requirement of 0.18um lines to the purity of target is 99.999% or even 99.9999%.
Impurity content
The impurities of target solid and the oxygen and water vapor of target pores are the main pollution source of the deposited films. The different uses of the Zr target are also different to the requirements of different impurity content. For example, pure aluminum and aluminum alloy target used in the semiconductor industry have special requirements to content of alkali metal and radioactive elements.
Grain size and grain size distribution
The target usually is polycrystalline structure, the grain size can be measured from micron to millimeter. For the same kind of target, the sputtering rate of target of fine grain size is faster than the coarse grain target sputtering rate, the thickness distributions of thin film of target sputtering with small grain size difference is more uniform.
