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Carbon (Pyrolytic Graphite) (C) Sputtering Targets

Carbon (Pyrolytic Graphite) (C) 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.

Carbon (Pyrolytic Graphite) (C) General Information

Standard carbon graphite targets can be very difficult to sputter. Carbon has one of the lowest sputter yields of all elements which is attributed to its Sp2 microstructure as well as its anisotropic electrical characteristics. Due to open spaces in Carbon's structural lattice, sputter rates are low and the process is very time-consuming. Standard carbon graphite targets are typically produced by hot-pressing. These targets are generally highly porous and contain randomly oriented grains which results in different localized effects, contributing to the low sputter yield.

On the other hand, Pyrolytic Graphite sputtering targets are much more directional and may have the ability to sputter at higher rates. Pyrolytic Graphite targets are made by chemical vapor deposition (CVD) and are grown atom-by-atom. The resulting material has better thermal, electrical and chemical properties. Due to the nature of the deposition process by CVD, Pyrolytic Graphite material approaches the theoretical density and is essentially non-porous so outgassing occurs quickly.

Carbon (Pyrolytic Graphite) (C) 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.