Tantalum target material: The core material from powder metallurgy to high-end sputtering
In the fields of semiconductor manufacturing and precise optical coating, the physical vapor deposition (PVD) technology has extremely strict requirements for the performance of sputtering targets. The purity, density, grain size and uniformity of the target directly affect the film formation quality and the stability of the equipment operation. Tantalum (Ta), due to its excellent electrical conductivity, stability and as an ideal barrier layer for copper interconnections, has become one of the key materials. To prepare tantalum targets that meet the requirements of high-end sputtering machines, a precise and controllable process flow is needed.
The starting point of the preparation process is high-purity tantalum powder. The tantalum powder produced by the sodium reduction method has a loose bulk density controlled within 1.8 - 2.6 g/cm3, with a particle size of approximately 2 - 3 micrometers. Subsequently, the tantalum powder is packed into a flexible latex sleeve and formed through cold isostatic pressing technology. The pressure at this stage needs to be greater than 200 MPa, and the holding time should exceed 20 minutes to ensure the acquisition of a high-density and uniformly stressed tantalum billet blank. The advantages of powder metallurgy are initially demonstrated in this stage, laying the foundation for obtaining fine and uniform internal structures in the subsequent process.
The formed green body needs to undergo high-temperature sintering to achieve densification. The sintering is carried out in a vacuum, with a temperature exceeding 2400°C and a holding time of no less than 1.5 hours. This process effectively removes impurities, closes pores, and enables atoms to fully diffuse and combine. The final sintered tantalum block can reach a density of 15.4 g/cm3 (approximately 99% of the theoretical density), with a purity of up to 99.99%, meeting the fundamental requirements for material purity in high-end applications.
The sintered billet then enters the plastic processing stage. Through rolling, the material undergoes a total processing deformation rate of 30% to 60%. This process can break down coarse grains, introduce dislocations, and provide a driving force for subsequent recrystallization. After rolling, the material undergoes heat treatment, with the heat treatment temperature set within the range of 25% to 45% of the melting point of tantalum (approximately 2996°C). The core purpose of this combined process (pressure processing + heat treatment) is to achieve complete recrystallization and obtain fine, equiaxed, uniform, and without obvious preferred orientation (no texture) grain structure. The average grain size of typical high-quality tantalum targets can be controlled below 100 micrometers. This uniform and fine structure is the key to ensuring the stability of the sputtering process and the uniformity of the film formation.
The processed tantalum target materials need to be metallurgically bonded with the copper backplate through diffusion welding or other methods to ensure efficient heat dissipation and mechanical strength during the sputtering process. In the PVD machine, high-energy ions bombard the surface of the tantalum target, causing tantalum atoms to be sputtered out in the form of metals or oxides and deposited on the silicon wafer or optical substrate, forming a film. In the semiconductor industry, tantalum films are mainly used as diffusion barriers for copper interconnects to prevent copper atoms from diffusing into the silicon medium, ensuring the reliability and performance of the chips.
Apart from its high-end form as a sputtering target material, tantalum also plays an indispensable role in other industrial fields: Capacitors: Approximately half of the tantalum consumption is used to manufacture tantalum capacitors. Its small size, large capacity, and high stability make it highly favored in high-end electronic devices, medical equipment, and military equipment. High-temperature alloys: Tantalum is added to nickel-based high-temperature alloys, which significantly enhances the alloy's high-temperature strength and creep resistance, and is mainly used to manufacture key hot-end components such as turbine blades for aircraft engines and gas turbines. Chemical processing equipment: Due to its excellent corrosion resistance (especially stability against inorganic acids), tantalum is widely used to manufacture reactors, heat exchangers, valves, and other key components in the chemical industry.
Chinese Manufacturer - Fortu Tech supplies Tantalum target to multiple countries and regions around the world. Its service coverage includes the United States, Canada, Russia, Germany, France, the United Kingdom, Italy, Sweden, Austria, the Netherlands, Belgium, Switzerland, Spain, Czech Republic, Poland, Japan, South Korea, as well as Chile, Brazil, Argentina, Colombia and other places in Latin America.
Fortu Tech in China can also produce and process Tantalum foil, Tantalum Capillary Tube, Tantalum billet, Tantalum sheet & plate, Tantalum rod, Tantalum wire, Tantalum tubes.
If you have any questions or need quote, price, please send email to info@fortu-tech.com.