Titanium is a widely used material in thin film technology due to its high strength, corrosion resistance, and compatibility with a broad range of substrates. In sputtering, titanium targets are applied to deposit thin metallic films directly, or to form compound films such as titanium nitride (TiN) and titanium dioxide (TiO₂). These coatings are valued in electronics, optics, energy devices, and protective applications.
Classification by Shape
Planar Targets
Planar targets are planar and are oriented parallel to the substrate during sputtering.
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Square targets are typically compact, measuring 50 mm to 150 mm on a side. Their symmetrical erosion and easy handling make them common in laboratory-scale systems.
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Disc targets are circular and symmetrical, having diameters from 50 mm up to 200 mm and thicknesses generally between 5 mm and 20 mm. They are the industry standard for use in magnetron sputtering equipment for microelectronics and optical coatings.
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Plate targets provide more material volume, with a thickness up to 25 mm. They are suitable for extended deposition runs or custom installations where chamber size requires special sizes.
Rotary Targets
Rotary designs improve target utilization and film uniformity by rotating during deposition.
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Cylindrical targets are common in large-area deposition, such as architectural glass, flat panel displays, and decorative films. Typical diameters are 100–200 mm, with lengths up to 1500 mm.
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Tube targets are hollow and manufactured with high-precision tolerances. Wall thickness is generally between 3 mm and 10 mm, with lengths of more than 2000 mm. They are used in optical and industrial PVD systems where there is a requirement for long, unbroken runs.
Applications
Semiconductors
Titanium thin films find use as adhesion layers and diffusion barriers for integrated circuits. Used with copper or aluminum interconnects, titanium helps bond and prevents unwanted diffusion.
Solar Cells
Titanium oxide (TiO₂) thin films are sputter-deposited from titanium targets and applied as electron transport layers to perovskite solar cells and dye-sensitized solar cells. The thin films increase light absorption and stability, which affect conversion efficiency.
Flat Panel Displays
Titanium and titanium nitride thin films make up electrodes and functional layers in display manufacturing. Their stability, conductivity, and resistivity control are instrumental for LCDs, OLEDs, and new display panels.
Protective and Decorative Coatings
Titanium and TiN thin films are applied in cutting tools, watch cases, automotive trim, and other wear-resistant parts. TiN, in particular, is prized for its golden hue as well as hardness and corrosion resistance.
Optical and Infrared Applications
Thin films of titanium are applied in mirrors, filters, and IR detectors. The ability to modify reflectivity, transparency, and thermal stability makes titanium coatings valuable in research as well as industrial optics.
Considerations in Target Selection
- Purity: 99.95% or greater purity is typically necessary for electronic use.
- Size and Shape: Must be matched precisely to the chamber specification.
- Surface Quality: Defect-free, smooth target surface is required for stable deposition.
- Alloys: For specialized coatings, titanium-aluminum or titanium-silicon targets are sometimes employed in specific situations.
Supply and Processing
Stanford Advanced Materials (SAM) offers titanium sputtering targets in planar and rotary forms, with options for custom machining and polishing. Batch-to-batch consistency and high-density fabrication are important for achieving stable thin film properties in both research and production environments.
