Technical indicators and considerations for purchasing metal target materials
For all metals, purity is one of the main performance indicators of the target. Why do you say that? The purity of the target material has a great influence on the performance of the membrane of the later product. But each product has different requirements for the purity of the target. , for example, the rapid development of microelectronics industry, silicon wafer size from 6 ", 8 to 12 "development", and the wiring width from 0.5 um reduce to 0.25 um, 0.18 um and 0.13 um, on the previous techniques are shown for the purity of target is 99.995% of the target material is completely can meet the technological requirements of 0.35 umIC, but now for 0.18 um lines on the purity of target is 99.999% or 99.9999%.
The purity of the target material. What is the content of the target material?
The oxygen and water vapor in the impurities and pores in the solid material of the target material after the series of target material processing are the main source of the deposition. Because the use is different so different target materials have different requirements for different impurities. For example, today's semiconductor industry USES pure aluminum and aluminum alloy targets, which have special requirements for both alkali and radioactive elements.
The density of the target material
Density is one of the key performance indicators (kpis) of target material. In the technology of target material in order to reduce the porosity of solid target material, improve the performance of sputtering film, generally is the requirement of target material must have a higher density. Because the main characteristic density of the target material has a great influence on the sputtering rate, and affects the electrology and optical properties of the film. The higher the target, the better the film performance.
Finally, the size of grain and the distribution of grain size
Usually, the target material is a polycrystalline structure, and the grain size can be from micron to millimetre. For the same target, the sputtering rate of the tiny target is faster than that of the larger target. The thickness distribution of the pellets is more evenly distributed.
Target material from the current production technology and production technology, is very strict with all conditions above, rather than simply because it has an important influence on the late products.