Tantalum target texture formation method, with tantalum ingot as raw material, the process is successively: forging, pickling, heat treatment, rolling, secondary pickling, secondary heat treatment, leveling, cutting, turning. In the application of the invention, the sputtering rate of the sputtered grains and the Angle distribution trajectory of the sputtered atoms will be close to the same, so that the coating with uniform thin film thickness will be obtained, and the material utilization rate of tantalum target will also be greatly improved. The invention not only fills the research gap in this aspect in China, but also stands in the technological frontier in the world.
Physical vapor deposition (PVD) is one of the most critical processes in the production of semiconductor chips. Its purpose is to deposit metal or metal compounds on silicon wafers or other substrates in the form of thin films, and then through the combination of photolithography and corrosion processes, and finally form complex wiring structures in semiconductor chips. Physical vapor deposition is accomplished by sputtering machine, and sputtering target is a very important key consumable used in the above process. Common sputtering targets are high-purity tantalum, as well as non-ferrous metals such as Ti, Al, Co and Cu.
As the chip size increases from 200mm(8 inches) to 300mm(12 inches), the corresponding sputtering target size must be increased to meet the basic requirements of PVD coating, at the same time, the line width is reduced from (130-180nm) to 90-45nm, based on the conductivity of the conductor and the matching performance of the barrier layer. The sputtering target will also be transformed from ultra-high purity Al/Ti system to ultra-high purity Cu/Ta system, and the importance of Ta target in the semiconductor sputtering industry is increasing, and the demand is also increasing.
The uniformity of the film thickness on the silicon wafer after sputtering is very important for the final product, which depends on the internal structure and texture orientation of the tantalum target. The grains are uniformly refined and the crystal orientation of the grains is close to the same target. During sputtering, the sputtered grains will have the same sputtering rate and the Angle distribution trajectory of the sputtered atoms will be close to the same. At the same time, the utilization rate of tantalum target materials has also been greatly improved.
