Magnetron sputtering is a physical vapor deposition (PVD) technology that uses magnetrons to confine electrons to a specific deposition path. This article provides a brief overview of sputtering techniques using magnetron systems and magnetron sputtering information.
1. DC Power Sputtering
Sputtering using DC power is effective for depositing conductive target metals, conductive oxides, or certain magnetic materials. It is not suitable for non-conductive materials.
2. Reactive Gas Sputtering
Also known as reactive DC sputter deposition, this technique enables higher deposition rates and precise stoichiometry for metallic targets. The target is sputtered in an environment of partial pressure of reactive gas. As the pressure increases, the target’s surface transitions from a metallic to thin oxide or nitride layer, and charge accumulates on the surface until it dissipates as an arc. The molecules that evaporate during the arc are deposited onto the substrate.
3. Pulsed DC Sputtering
Pulsed DC power is used in magnetron sputtering processes that are prone to arcing. A negative bias is applied, with a reverse bias to remove charge accumulation between pulses. Pulsed sputtering minimizes arcing during a reactive process, reducing the chance of unwanted film properties and inferior performance.
High power impulse magnetron sputtering, better known as HIPIMS, is a technique that uses short, intense pulses of DC power to form a highly dense plasma near the target to boost the sputtering rate. The pulses are delivered with a low duty cycle to minimize excess heat and maintain a manageable average operating power.
5. Facing Target Sputtering
Facing target sputtering, or low-damage sputtering, uses two magnetron sources placed opposite to one another at right angles to the substrate. It is intended to minimize the risk of damage to a soft or organic substrate. This configuration is designed to confine plasma between the sources in order to reduce electron density which reaches the substrate.
6. Radio Frequency Magnetron Sputtering
Certain materials with high DC impedance cannot be sputtered using DC power. For these applications, it is possible to deliver power using radio frequencies and an automatic impedance matching network to maintain a plasma. Radio frequency sputtering is used to deposit materials like oxides, nitrides, and ceramics.