New Production Method for Tungsten-Titanium Target

Physical vapor deposition (PVD) is widely used in optical industry, electronic industry, and information industry. The applications of PVD include integrated circuits, liquid crystal displays (LCD), industrial glass, camera lenses, information storage, ships, chemicals, etc. The alloy target used in PVD is one of the most important raw materials in the manufacturing process of integrated circuits and liquid crystal displays.

Tungsten-titanium target is a typical alloy target. Large-scale semiconductor integrated circuits, solar cells, etc. use a tungsten-titanium target for PVD coating to form a barrier layer. Generally, the material for the tungsten-titanium target for sputtering requires a purity ≥99.9% and a relative density ≥99%. And it must has a uniform microstructure, and has no crack defects.

With the development of PVD technology, the quality requirements for alloy targets are increasing. The finer the grain size of the alloy target, the more uniform the composition of the alloy, and the smaller the surface roughness, the thiner film formed on the silicon wafer by PVD. In addition, the purity of the formed film is closely related to the purity of the alloy target. Therefore, the quality of the film after PVD mainly depends on the purity, density, grain size and microstructure of the alloy target.

The preparation of the tungsten-titanium target for semiconductor sputtering comprises the steps of: forming a tungsten-titanium target embryo by filling a mold with a mixed powder of high-purity tungsten powder and titanium powder, and then subjecting the mixed powder to a cold press forming process, The tungsten-titanium target embryo is further subjected to vacuum hot press sintering to form a tungsten-titanium target. The vacuum hot pressing sintering process comprises: vacuuming the vacuum hot pressing furnace to an absolute pressure of 100 Pa or less, and raising the temperature to 900 ° C to 1100 ° C at a heating rate of 5 ° C / min to 10 ° C / min, and maintaining the temperature for 60 min to 90 min. Then, the relative pressure of the inert gas to the vacuum hot press is -0.08 MPa to -0.06 MPa. Finally, the pressure is increased to a maximum pressure at a pressurization speed of 0.1 MPa/min to 0.4 MPa/min, and the temperature is raised to a maximum temperature at a temperature increase rate of 5 ° C/min to 10 ° C/min, and the maximum temperature is 1100 ° C to 1250 ° C. The maximum pressure is between 20 MPa and 30 MPa, and the holding pressure is maintained for 30 minutes to 60 minutes under the maximum pressure and the maximum temperature.

The new tungsten-titanium target production method has fewer process steps, a quick production. The tungsten-titanium target prepared has a density greater than or equal to 99%, and also has a uniform microstructure and excellent sputtering performance.

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