PNNL has two, multi-cathode magnetron sputter deposition systems that can be used to deposit multi-component alloy thin films. The first system is capable of depositing up to five elements simultaneously, while the second system is capable of depositing up to three elements concurrently. A combinatorial approach can be used to deposit alloy samples with composition gradients, and mathematical models have been developed to predict the resulting composition profile. The five-cathode system is equipped with 2-inch diameter magnetron cathodes powered by direct current (DC) power supplies. The three-cathode systems uses 3-inch diameter magnetron cathodes powered by both DC and radio frequency (RF) power supplies. The flux is monitored using quartz crystal balance, enabling deposits of a multitude of alloy compositions of most light metals and all transition metals. The three-cathode system also is fitted with thermal evaporation sources and multipocket e-beam deposition sources.
Films with thickness ranging from 2 nm-20 μm can be deposited, and substrate sizes up to 4-inch diameter can be accommodated. Most elements can be sputtered, except group I and group II elements (Li, Na, K, Ca etc.). A variety of targets are available (e.g., Al, Mg, Y, V, Ce, W, Au, Ag, Si, or Pt), or they can be purchased from commercial vendors. Process gases (N2 and O2) also can be used to deposit metal oxides/nitrides via reactive sputtering.
- Deposition can be performed at room or elevated temperatures (up to 800°C) using specially designed substrate holders.
- Alloy thin films can be directly deposited on a variety of substrates, e.g., transmission electron microscopy (TEM) chips with silicon nitride windows for TEM examination.
- Mathematical models have been developed to predict the resulting composition profile.
- Five-cathode system is equipped with the strongest magnetrons (NdFeB magnets), capable of depositing ferromagnetic metals.
Use of these systems is coordinated with capability experts and via collaborative funding proposals or contract. The three-cathode system is part of the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the U.S. Department of Energy's Office of Biological and Environmental Research, which also is accessible via user proposal.
Name: Darrell Herling
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