In the chip industry as a high-tech commanding height, sputtering targets are essential raw materials for the manufacture of VLSIs. It uses the ions generated by the ion source to accumulate in a high vacuum to form a high-velocity ion beam that bombards the solid surface. The ions and solid surface atoms exchange kinetic energy, so that the atoms on the solid surface leave the solid and deposit on the substrate On the surface, the bombarded solid is the raw material for the deposition of thin films by sputtering, which is called the sputtering target. The target is the core material of the sputtering process.
The inside of the unit device in an integrated circuit is composed of a substrate, an insulating layer, a dielectric layer, a conductor layer, and a protective layer, etc., among which, the dielectric layer, the conductor layer, and even the protective layer all need to use a sputtering coating process, so the sputtering target is prepared One of the core materials of integrated circuits. Targets for coating in the field of integrated circuits mainly include aluminum targets, titanium targets, copper targets, tantalum targets, tungsten-titanium targets, etc. The target materials are required to have high purity, generally above 5N (99.999%).
Target classification There are many types of sputtering targets, and according to different classification criteria, there can be different categories. Sputtering targets can be classified by shape, chemical composition and application field.
Sputtering target: the volume is small, But is the core technology
High-purity metal sputtering targets are mainly used in wafer manufacturing and advanced packaging processes. Taking chip manufacturing as an example, we can see that from a silicon wafer to a chip, there are 7 major production processes, which are diffusion (ThermalProcess) Photo-lithography, etching (Etch), ion implantation (IonImplant), film growth (DielectricDeposition), chemical mechanical polishing (CMP), metallization (Metalization), the equipment, materials and Processes correspond to each other. Sputtering targets are used in the process of "metallization". The thin film deposition equipment uses high-energy particles to bombard the target and then form a metal layer with a specific function on the silicon wafer, such as a conductive layer and a barrier layer.
Sputtering target industry chain
The sputtering target industry chain is basically pyramid-shaped. The industrial chain mainly includes metal purification, target manufacturing, sputter coating and terminal application.
The terminal application link is the largest field in the entire industrial chain, including semiconductor chips, flat panel displays, solar cells and other fields.
The purity of raw materials is a key factor that affects the performance of thin film materials. High-purity metal raw materials are the basis of target manufacturing.
The purification of high-purity metals is divided into chemical purification and physical purification. In practical applications, a variety of physical and chemical means are commonly used to achieve the preparation of high-purity materials.
Although China has abundant non-ferrous metal mineral resources, there is still a certain gap between China's high-purity metal preparation technology and foreign countries. High-purity metals have a large proportion and need to be imported from abroad.
Different downstream application fields have different requirements for the required sputtering targets. For example, semiconductor chips have set extremely stringent standards for the sputtering target metal material purity and internal microstructure, etc., and need to master the production process. The key technology and long-term practice can make products that meet the process requirements. Therefore, semiconductor chips have the highest requirements for sputtering targets and are also the most expensive.
In contrast, the purity and technical requirements of sputtering targets for flat panel displays and solar cells are slightly lower, but as the size of the target increases, indicators such as welding bonding rate and flatness of the sputtering target are proposed. higher requirement.
The growth in downstream demand has driven the rapid growth of the sputtering target market.
According to the China Electronic Materials Industry Association, the global high-purity sputtering target market size was approximately US $ 11.36 billion in 2016, a year-on-year increase of nearly 20%, of which the target for flat panel displays (including touch screens) was US $ 3.81 billion, accounting for 34%, semiconductor targets 1.19 billion US dollars, accounting for 10%, solar cell targets 2.34 billion US dollars, recording media targets 3.35 billion US dollars. It is estimated that by 2019, the global high-purity sputtering target market will exceed USD 16.3 billion, with a compound annual growth rate of 13%.
China's huge consumer demand is conducive to the transfer of downstream industries to the local area, thereby increasing the growth rate of domestic sputtering targets. In recent years, the downstream industry of the sputtering target industry chain has faced varying degrees of cost pressure. The semiconductor industry has a trend of industry transfer to the market. China is the world's largest integrated circuit first-hand trading market, with sales exceeding 50% of global sales. It has great attraction for industrial transfer, so the growth rate of the domestic target market will also be higher than the global growth rate.
Sputtering target supply market structure
The sputtering target material required by the sputtering coating process has high purity and strong professional applicability. Since the day of its birth, high-purity sputtering target manufacturers represented by the United States and Japan have implemented strict confidentiality measures on core technologies, which has led to the obvious regional clustering characteristics of the sputtering target industry worldwide.
Sputtering target producers represented by multinational groups such as Honeywell (USA), Nippon Mining Metals (Japan), Tosoh (Japan), etc., were earlier involved in this field and engaged in related businesses. The top five manufacturers account for more than 80%.
The industrial chain of the US-Japan multinational group is complete, including all aspects of metal purification, target manufacturing, sputter coating and terminal application. Relying on advanced purification technology occupies a very favorable position in the entire industrial chain, with strong bargaining power.
The domestic sputtering target manufacturing level has reached the international advanced level, but the scale and volume are still small, and it is currently in a stage of rapid growth.
The sputtering target industry started late in China and is still a relatively new industry. In recent years, with the transfer of downstream industries to China, domestic targets have begun to achieve breakthroughs.
In the past, there was a good foundation for optimizing the market pattern, technological breakthroughs in domestic enterprises and policy support. Later, there was Sino-US trade friction as a catalyst, and the localization of target materials was being accelerated. Compared with the global market of US $ 13 billion, and the domestic market of around US $ 5 billion, the industry still has huge room for replacement.
There are two main types of sputtering targets in China: semiconductor targets are produced by NBJF Electronic Material Technology Group, BJYY; the other is panel targets, manufacturers are mainly FJAS, LYSF Electronic Material Technology Group, GXJL Optoelectronics. Leading companies such as NBJF Electronic Materials Technology Group and other high-purity sputtering target manufacturers have entered the list of suppliers of major wafer foundries after achieving technological breakthroughs.
Target technology development trend
Sputtering target development towards large size and high purity
The technological development trend of sputtering targets is closely related to the technological innovation in downstream applications. With the technological progress of the application market in thin-film products or components, the sputtering targets also need to change.
In the downstream application fields, the semiconductor industry has the highest quality requirements for sputtering targets and sputtering films. As larger-sized silicon wafers are manufactured, the sputtering targets are also required to move toward larger sizes At the same time, it also puts forward higher requirements for the crystal orientation control of the sputtering target.
The purity of the sputtered film is closely related to the purity of the sputtering target. In order to meet the needs of semiconductors with higher precision and finer micron technology, the purity of the sputtering target required continues to rise, even reaching 99.9999% (6N) purity.
As a strategic emerging industry focusing on encouraging development, and adopting industrial policies, the "13th Five-Year Plan" proposes that by 2020, the self-sufficiency rate of major key materials will reach more than 70%, which will initially achieve China's strategic transformation from a material power to a material power. At present, Chinese enterprises have made breakthroughs in the field of targets, and under the current economic background, domestic targets will surely achieve great development.