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Tungsten (W) Sputtering Targets

Tungsten (W) Sputtering Targets Overview

Our comprehensive offering of sputtering targets, evaporation sources and other deposition materials is listed by material throughout the website. Below you will find budgetary pricing for sputtering targets and deposition materials per your requirements. Actual prices may vary due to market fluctuations. To speak to someone directly about current pricing or for a quote on sputtering targets and other deposition products not listed, please click here.

Tungsten (W) General Information

Tungsten, also known as Wolfram, is one of the densest elements in the world. It has a density of 19.3 g/cc, a melting point of 3,410°C, and a vapor pressure of 10^-4 Torr at 2,757°C. It is lustrous and grayish-white in appearance. It is known to have the highest melting point of all metals and its characteristic hardness can make it very difficult to machine and forge in pure form. Tungsten is commonly used to make electric filaments. Tungsten carbide is found in drills, saws, and jewelry. Tungsten is evaporated under vacuum for the production of semiconductors, fuel cells, and sensors.

Tungsten (W) Specifications

* This is a recommendation based on our experience running these materials in KJLC guns. The ratings are based on unbonded targets and are material specific. Bonded targets should be run at lower powers to prevent bonding failures. Bonded targets should be run at 20 Watts/Square Inch or lower, depending on the material.

* Suggested maximum power densities are based on using a sputter up orientation with optimal thermal transfer from target to the sputter cathode cooling well. Using other sputtering orientations or if there is a poor thermal interface between target to sputter cathode cooling well may require a reduction in suggested maximum power density and/or application of a thermal transfer paste. Please contact techinfo@lesker.com for specific power recommendations.

Z-Factors

Empirical Determination of Z-Factor

Unfortunately, Z Factor and Shear Modulus are not readily available for many materials. In this case, the Z-Factor can also be determined empirically using the following method:

• Deposit material until Crystal Life is near 50%, or near the end of life, whichever is sooner.
• Place a new substrate adjacent to the used quartz sensor.
• Set QCM Density to the calibrated value; Tooling to 100%
• Zero thickness
• Deposit approximately 1000 to 5000 A of material on the substrate.
• Use a profilometer or interferometer to measure the actual substrate film thickness.
• Adjust the Z Factor of the instrument until the correct thickness reading is shown.

Another alternative is to change crystals frequently and ignore the error. The graph below shows the % Error in Rate/Thickness from using the wrong Z Factor. For a crystal with 90% life, the error is negligible for even large errors in the programmed versus actual Z Factor.