The Need

Sputter deposition is one of the dominant techniques used in manufacturing films and coatings in many industries. Conventional sputtering uses an “on-axis” geometry, i.e., the substrate directly faces the sputter target. Due to the energetic bombardment of sputtered atoms, sputtering is regarded as a “messy” process, which can not be used to grow high-quality single crystalline films and can not compete with techniques, such as molecular-beam epitaxy (MBE), pulsed laser deposition (PLD), and chemical vapor deposition (CVD). The "off-axis" geometry has previously been used in sputtering at high pressure. The idea is that atoms sputtered off-axis of the target, under high pressure, experience many scattering events with the sputtering gas (argon and possibly oxygen) and slow down before depositing on the substrate. Consequently, the energetic bombardment is largely minimized. However, high pressure sputtering may cause poor quality films due to varying scattering profiles of different species of atoms, resulting in the stoichiometry of the deposited films being significantly different from that of the target.

The Technology

Dr. Fengyuan Yang, a researcher at The Ohio State University, has developed an off-axis sputtering deposition technique that differs significantly from conventional on-axis and off-axis sputtering techniques, resulting in drastically improved crystalline quality for a broad range of materials. The comprehensive set of parameters in the film growth process and unique preparation of the sputtering target enable growth of high-quality complex films. This technology has been published in over 25 peer-reviewed journals since 2010.

Commercial Applications

• Computer hard-disks
• Ferromagnetic semiconductors (spintronics)
• Deposition of antireflective coatings
• Applications that require thin or single-crystal coating

Benefits/Advantages

• Eliminate the energetic bombardment problem in conventional sputtering techniques
• Preserves the stoichiometry of the film from target to substrate
• Crystalline quality is comparable to state-of-the-art semiconductor films