Titanium target

Titanium target is a special material mainly used in physical vapor deposition (PVD) and magnetron sputtering (Magnetron Sputtering) technology. Among them, PVD technology is widely used in the production of advanced coatings, while magnetron sputtering is commonly used in the manufacturing process of semiconductor chips and electronic components. Titanium targets are made of pure titanium or titanium alloy as the main component and are carefully manufactured. Its unique advantages include extremely high hardness and density, as well as excellent corrosion resistance, which makes it stable in a variety of environments. In addition, titanium targets have good thermal conductivity and high purity, providing excellent performance for sputtering thin film technology.
Titanium target is a high-purity titanium or titanium alloy slab material made through vacuum melting-investment casting process. Its most notable properties are high purity and excellent density. The density of high-quality titanium targets can reach more than 99.5%, and the impurity elements are extremely low, such as Fe, Si, O, N, H and other elements are less than 100ppm. This makes the physical and chemical properties of the titanium target far exceed that of ordinary industrial pure titanium.
In addition, titanium targets offer excellent uniformity. During the preparation process, multiple melting and quenching treatments were used to effectively improve the structural uniformity of the titanium target. The target surface is smooth and clean, the internal structure is dense, and the grains are fine, which ensures the uniformity of the deposited film layer. Titanium targets also have excellent thermal conductivity and small thermal stress, making them less prone to cracking and able to withstand high-power sputtering or arc evaporation processes. In addition, the titanium target has high mechanical strength, which can effectively extend its service life and reduce target loss, thus improving its overall performance and use value.

⑴Magnetron sputtering:
Preparation of optical coatings, such as anti-reflective coatings for spectacle lenses, anti-reflective coatings for lenses, etc.
Prepare titanium-based magnetic records for data storage such as computer hard drives.
Preparation of titanium-based conductive films for use as electrodes in LCD displays.
⑵Laser sputtering:
Prepare surface hardened layer of mechanical parts to improve wear resistance.
Preparation of surface coatings on biomedical titanium alloy materials to improve biocompatibility.
⑶Arc evaporation:
Preparation of transparent conductive film for front electrode of solar cell.
Preparation of titanium-based reinforcement layers of composite materials.
⑷Electron beam evaporation:
Preparation of back electrode for rutile solar cells.
Preparation of anti-reflective films and passivation films for photovoltaic devices.
Preparation of coatings for automotive shock absorbers.
⑸Ion plating:
Preparation of bioactive coatings for titanium alloy implants in dental and orthopedic surgery to improve the bonding force between bone and implants.
Preparation of wear-resistant and anti-corrosion coatings for automobile engine pistons.
Prepare surface hardened layer of metal cutting tools to improve cutting performance.
⑹ Chemical plating:
Preparation of conductive interconnect layers for electronic circuit boards.
Preparation of gloss coating for automobile decorative parts.
Preparation of high reflectivity coatings for optical components.
⑺Atomic layer deposition (ALD):
Preparation of diffusion barrier layers for new types of memories such as copper interconnects.
Preparation of optical filters for image sensors.
Preparation of surface layers for solar cells.
⑻3D printing:
Preparation of custom titanium alloy implants and stents for medical use.
Preparation of lightweight structural parts for the aerospace industry.
Preparation of metal functional parts for complex shapes.

⑴Metallurgy
Principle: Vacuum arc smelting and other technologies are used to smelt high-purity titanium, and then undergo multiple melting and quenching, cold rolling or forging treatments to make titanium targets.
Process flow: material selection→smelting→quenching and forging→machining→testing
Advantages: Titanium target material has high density, high purity and good uniformity.
Disadvantages: complex process, high energy consumption, and high cost.
⑵Powder sintering method
Principle: High-purity titanium powder is pressed and formed, and then sintered and densified to make a titanium target.
Process flow: ingredients→press forming→sintering→machining→testing
Advantages: simple process and low cost.
Disadvantages: The density is slightly lower, the pores are slightly more, and the uniformity is slightly worse.

⑶Thermal spraying method
Principle: Thermal spraying technology is used to spray molten titanium powder on the base material with high-speed airflow to form a titanium target.
Process flow: material selection → thermal spraying → mechanical processing → testing
Advantages: The process is simple, the quality is controllable, and titanium targets can be prepared on various substrates.
Disadvantages: The surface quality is slightly poor and requires subsequent mechanical processing.
⑷3D printing
Principle: Use energy sources such as lasers to sinter titanium alloy powder layer by layer and directly print and shape titanium targets.
Process flow: ingredients → 3D printing and molding → post-processing
Advantages: Targets of various complex shapes can be customized as needed.
Disadvantages: slower printing speed and higher cost.
⑸Spin spray method
Principle: Using the rotating electrode jet spray method, the molten titanium metal is atomized and deposited on the collector to form a flake-shaped titanium target.
Process flow: smelting → rotary spray molding → heat treatment → mechanical processing → testing
Advantages: fast forming speed and relatively uniform quality.
Disadvantages: Adhesion is slightly poor and requires subsequent heat treatment.
⑹Sputtering bonding method
Principle: First, a layer of pure titanium film is sputtered on the substrate, and then the titanium target is prepared by high-temperature hot-pressing bonding.
Process flow: substrate processing → sputtering film formation → hot press bonding → mechanical processing → inspection
Advantages: high bonding strength, tight bonding between target material and substrate.
Disadvantages: complex process and long preparation time.
⑺Ion implantation method
Principle: Inject nitrogen and carbon plasma into a high-purity titanium matrix, and then undergo heat treatment to form a titanium anion compound on the surface to prepare a composite target.
Process flow: bombardment treatment → ion implantation → heat treatment → mechanical processing → detection
Advantages: Surface functionalized composite targets can be prepared.
Disadvantages: Only thin targets can be prepared, and it is more difficult to use in large areas.

Thicker titanium targets have a longer sputtering life, reduce the frequency of target changes, and improve work efficiency. However, the film thickness distribution is uneven and the target needs to be rotated to improve it. Thinner titanium targets have a more uniform film thickness distribution.
The film prepared by high-purity titanium target material (such as 99.99%) has high purity and good performance. However, the target material wears out quickly, increasing operating costs. Although low-purity titanium targets have cost advantages, the impurity content of the deposited film is high, which affects the film performance.
The high-density titanium target film layer has good density and strong adhesion. However, too high a density will also increase stress within the membrane. Titanium targets with moderate density can obtain a film layer with balanced performance.
Bright and flat titanium targets deposit films with better surface quality. But over-polishing can also cause problems with particle shedding. Moderate surface roughness helps improve film adhesion.
Large-size titanium targets have high working efficiency, but have poor uniformity and uneven film thickness distribution. Small-area targets can obtain a uniform film layer but the efficiency is low.
High-strength titanium targets have high mechanical strength, long service life, and good wear resistance, but the production process is difficult. Ordinary titanium targets have low mechanical strength, are prone to wear, and have a short service life.
A titanium target with uniform density can make the density of each area of ​​the film layer consistent and obtain a film layer with uniform performance. Target materials with uneven density will lead to unstable film quality.
Different impurity elements have different effects on the properties of titanium films. For example, Fe pollution seriously affects the electrical properties of the film, while Si mainly affects the mechanical properties. Choosing titanium targets with appropriate impurity types can optimize film performance.
High-priced titanium targets usually have excellent performance, but the cost of use is also high. Choosing cost-effective products can reduce costs while ensuring film quality.

China's titanium target production in 2020 is about 12,000 tons, which only meets about 1/3 of the domestic market demand. It is expected that by 2025, China's titanium target production capacity will increase to about 20,000 tons.
The world's major titanium target manufacturers include Praxair in the United States, Toho Mining in Japan, Western Titanium Industry in China, Baoti Group, etc. The top five in terms of market share account for approximately 65% ​​of the global total production.
In terms of target size, the 2-4 inch size accounts for the largest proportion of output, accounting for about 55% of the total. Large-size titanium targets are growing faster and are expected to reach about 35% of the total by 2023.
From the perspective of target materials, high-purity titanium targets have the largest demand, accounting for approximately 60% of the total in 2020. Titanium alloy targets also have strong demand, and their growth rate is rapid.
Among the downstream applications of titanium targets, the semiconductor manufacturing industry has always been the largest demand end. However, the new energy vehicle industry has the fastest growing demand, and it is expected that its demand will exceed that of the semiconductor industry by 2025.

Prospects:
Due to its excellent physical and chemical properties, titanium targets are widely used in optical coatings, decorative coatings, wear-resistant coatings, electronic devices, solar cells and other fields, and their development prospects are very broad. With the advancement of science and technology, new application fields are constantly being discovered. For example, in the fields of new energy, biomedicine, etc., the application of titanium targets is also expected to be further expanded.
Technical difficulties faced:
Improving the purity of titanium targets: Although the current purity of titanium targets can already meet the needs of most applications, for some high-end applications, such as solar cells, superconducting materials, etc., the purity of titanium targets needs to be further improved.
Optimizing the preparation process of titanium targets: There are still some problems in the current preparation process of titanium targets, such as high cost, low efficiency, poor environmental performance, etc., which need to be solved through technological innovation and process improvement.
Improve the service life of the titanium target: During the coating process, the titanium target will be bombarded by high-energy ions, causing wear on its surface and affecting its service life. Therefore, how to improve the wear resistance and service life of titanium targets is an important technical problem.
Future direction:
Develop new titanium targets: Through material science and process innovation, new titanium targets are developed to meet the needs of higher-end applications.
Optimize the preparation process: Through process optimization and equipment upgrading, we can improve the preparation efficiency of titanium target materials, reduce production costs, and improve the environmental performance of the product.
Expand application fields: Through technology research and development and market development, the application fields of titanium targets will be further expanded, such as new energy, biomedicine, etc.
In general, titanium targets, as an important coating material, have broad development prospects, but they also face some technical challenges. Through continuous technological innovation and market development, it is expected to achieve greater development in the future.