In the field of target forging technology, a semiconductor tantalum target and its forging method are disclosed. Tantalum ingot was upset and drawn under the condition that the deformation amount was 20% ~ 40% and the single deformation amount was less than or equal to 10%. After pickling, tantalum ingot was subjected to the first vacuum heat treatment at 1250-1400 ℃. After upsetting and pickling were repeated, vacuum heat treatment was conducted at 950 ~ 1150℃ for the second time. The semiconductor tantalum target material is obtained by repeating upsetting and drawing, pickling and vacuum heat treatment at 950 ~ 1150℃ for two times. The invention compacts the loose structure, welds the microscopic holes and increases the density of tantalum target blank by means of four upsetting and drawing forging and adopting reasonable multi-pass small deformation amount. The average grain size of the semiconductor tantalum target is between 50 and 70μm, and the overall texture ratio is less than 30%.
Pure tantalum target material is mainly used in the preparation of diffusion barrier layer between copper interconnect and silicon substrate in advanced semiconductor technology and is the key material in copper interconnect process. At present, very large scale integrated circuits have gradually developed into Cu/Ta sputtering targets. With the rapid development of integrated circuits towards very large scale and high computing speed, tantalum sputtering targets have become the key raw materials in semiconductor industry, which is irreplaceable and has a broad application prospect. In the process of sputtering, the grain size and texture orientation of tantalum target seriously affect the sputtering rate and the uniformity of sputtering film is its densely packed surface, which preferentially slips during plastic deformation. As a result, the grain orientation of tantalum target after final plastic deformation and annealing treatment is mainly, which belongs to the "inherent texture band" of tantalum metal. And the texture has a slow sputtering rate, so it is necessary to reduce the texture components as much as possible. Therefore, it is very important to control the grain orientation, especially the texture proportion of.
In the prior art, the manufacturing method of semiconductor tantalum target material is usually smelting casting method (forging + rolling mode after smelting tantalum ingot), among which the original ingot greatly affects the quality and process performance of the later processed products, and the control of the quality of the original ingot is also important. Secondly, fine and uniform microstructure can be obtained through reasonable forging process, so the forging process of key technologies is particularly demanding.
