Tungsten sputtering targets are made of high-purity tungsten metal, which is usually fragile and difficult to process. If tungsten is made into a very pure material, it can maintain its hardness (more than that of many steels), and it has enough ductility to make it easy to process. It is processed by forging, stretching or extrusion. Tungsten objects are also usually formed by sintering.
Of all metals in pure form, tungsten has the highest melting point (3422 °C, 6192 °F), lowest vapor pressure (at temperatures above 1650 °C, 3000 °F), and the highest tensile strength. Tungsten has the lowest coefficient of thermal expansion of any pure metal. The low thermal expansion and high melting point and tensile strength of tungsten originate from strong covalent bonds formed between tungsten atoms by the 5d electrons. Alloying small quantities of tungsten with steel greatly increases its toughness.
XK has rich experience in producing tungsten sputtering target with various shapes and purity, which are mainly applied to semi-conductive & micro-electronics. As a component of the thin-film transistors used in TFT-LCD screens, tungsten layers is extremely stable under high temperature environment, due to the highest melting point of all metals. Thanks to our special forming processes, our tungsten sputtering targets possess higher density, smaller average particle size as well as higher purity, so that you can benefit from a faster process due to higher sputtering speeds and obtain very homogeneous tungsten layers.
The microstructure can be adjusted by our flexibility production process, to achieve your desired effect. If the grains of the sputtering target are uniformly aligned, the user can benefit from constant erosion rates and homogeneous layers. Following are two micrographs of our tungsten sputtering target, the average grain size＜100μm.
The chemical purity is crucial to a metal sputtering target, if the purity is higher, the films will possess a more outstanding level of electrical conductivity and minimized particle formation during the PVD process. Following is a typically Certificate of analysis for 3N5 tungsten sputtering target.
1. Metallic elements were analyzed by GDMS and ICP-OES.
2. Gas elements were analyzed by LECO.
Preparation process of tungsten sputtering target
Material Preparation-Sintering-Chemical Analysis-Rolling-Annealing-Metallographic Inspection-Machining-Dimensional Inspection-Cleaning-Final Inspection-Packaging-Shipment
Tungsten sputtering target and preparation method thereof
Mix tungsten powder with purity above 99.95% and particle size 2.2~2.6μm; 180~250MPa, 5~10 minutes cold isostatic pressing; 2300℃~2400℃, 8~12 hours of intermediate frequency induction sintering; 1450~ After annealing at 1550℃ for 90~180 minutes, it is hot-rolled to a thickness of 5~15mm by multiple passes, and the total deformation of hot rolling is greater than 60%. After annealing at 1300~1400℃ for 90~150 minutes, mechanical processing is carried out. The amount of mechanical processing on the surface is ≥1.5mm; the final tungsten target material is not only excellent in performance, but also relatively simple in process, and does not require high equipment.
Other alloy forms of tungsten sputtering target
Tungsten titanium, tungsten copper, tungsten manganese, tungsten nickel, tungsten molybdenum alloy targets, etc.