High purity tungsten

Pure tungsten materials with a purity of 99.999% (5N) and 99.9999% (6N) are called high-purity tungsten. The total impurity element content of high-purity tungsten should be controlled between 1 ppm and 10 ppm (10-6～10-5). For some special impurity elements, such as radioactive elements, alkali metal elements, heavy metal elements and gases Elements etc. also have special requirements. Since the radioactive elements U and Th have a rays, they can cause "soft errors" in the memory circuit and affect the quality and performance of the circuit. Therefore, in the impurity elements of high-purity tungsten, the content of U and Th should be particularly low. Said it should be as low as 1 ppb (that is, 1×10-9) or less, and as low as 0.1 ppb (1×10-10). In addition, high-purity tungsten also has strict requirements on the content of alkali metal elements (K, Na, Li). High-purity tungsten is mainly prepared into pure metal targets or alloy targets, and functional films that meet the requirements are obtained by magnetron sputtering. Because high-purity tungsten (5 N or 6 N) has high resistance to electron migration, high-temperature stability and the ability to form stable silicides, it is used as a gate, connection and barrier metal in the form of thin films in the electronics industry. High-purity tungsten and tungsten silicon and tungsten-titanium sputtering targets are often applied in the form of thin films for ultra-large-scale integrated circuits as resistance layers, diffusion barriers, transition layers, etc., and as gate materials and connections in metal oxide semiconductor transistors Materials, etc. The rapid development of modern electronics, semiconductors, and photovoltaic industries has almost exacting and perfect purity requirements for materials, especially metal materials. High-purity tungsten plays a very important role due to its extremely high performance.

High purity molybdenum

Pure molybdenum materials with a purity of 99.99% (4N) and 99.999% (5N) are called high-purity molybdenum. The total impurity element content of high-purity molybdenum is correspondingly controlled between 100 ppm to 10 ppm (10-4 to 10-5). Like high-purity tungsten, there are special requirements for the content of some special impurity elements in high-purity molybdenum, such as radioactive elements, alkali metal elements, heavy metal elements and gas elements. Since high-purity molybdenum is mainly used in the field of target materials, the content of U+Th and alkali metals is generally required to be very low. Due to the late experimental development of high-purity molybdenum materials, industrial manufacturing is even more difficult to talk about. Its use was often replaced by industrial grade or powder metallurgical grade ordinary molybdenum materials a few years ago. However, in recent years, the rapid progress of the semiconductor industry and the rapid upgrading of high-precision electronic products have greatly promoted higher and newer requirements for basic materials. Like high-purity tungsten, high-purity molybdenum is mainly prepared as a pure metal target or alloy target, and a functional film that meets the requirements is obtained by magnetron sputtering. The working principle of sputtering is to bombard the target with high-speed particles, so that the metal atoms on the surface of the target are separated from the target and deposited on the glass or other substrates in the form of a thin film, finally forming a complex wiring structure. Compared with ordinary molybdenum targets, high-purity molybdenum sputtering targets can form higher-quality thin-film materials due to their extremely low impurity content and high chemical purity. They are now widely used in the manufacture of thin-film transistor liquid crystal displays (TFT- LCD); wiring materials for large-scale integrated circuits in the semiconductor industry; new thin-film solar cells in the solar industry; and other high-tech materials. Large-scale integrated circuits such as semiconductors require extremely high purity of metal materials. Due to its excellent performance, high-purity molybdenum has become the first choice for high-end quality materials in modern electronics, semiconductor, and photovoltaic industries.

Sputtering target

Principle of Sputter Magnetron Sputtering

Sputter in the dictionary means: (plant) splash. The so-called sputtering refers to objects being sputtered and scattered when they are hit by ions. Objects scattered by sputtering adhere to the target substrate to form a thin film. The blackening phenomenon that is common near the socket of a fluorescent lamp is the most appreciated example around. This is caused by the electrode of the fluorescent lamp being sputtered and attached to the surroundings. Since the sputtering phenomenon was discovered in the 19th century, it has been unpopular, especially in the field of discharge tubes. In recent years, it has been cited in the film production technology with good efficiency and will become a usable thing. The application research of thin film production was originally mainly by Bell Lab. and Western Electric Company. In 1963, a continuous sputtering device with a total length of about 10m was made. In 1966, IBM released the high-frequency sputtering technology, which made insulator thin films also possible. After various studies, it has reached the goal of "no matter what the material of the substrate, it can be covered with a thin film of any material". To make a thin film, at least a substrate for the device and a tool (internal mechanism) to maintain the vacuum condition are required. This kind of props is necessary to make a space and use a vacuum pump to extract the gas inside. Sputter sputtering definition: In a relatively stable vacuum state, a glow discharge is generated between the anode and the cathode, and the gas molecules between the electrodes are ionized to generate a charged charge. The positive ions are accelerated by the negative potential of the cathode and hit the target on the cathode. , Sputtering its atoms and other particles, the spattered atoms are deposited on the anode substrate to form a thin film, this physical phenomenon is called sputtering.