Achieving a High Thermally Conductive One Micron AlN Deposition by High Power Impulse Magnetron Sputtering plus Kick

Area of Science:

• Materials Science
• Thin Film Deposition
• Plasma Physics

Background:

• High-power impulse magnetron sputtering (HiPIMS) plus kick is an advanced physical vapor deposition technique.
• Nitride deposition, particularly AlN, faces challenges like low surface diffusion and ion damage.
• Precise control over ion energy is crucial for high-quality thin film growth.

Purpose of the Study:

• To systematically investigate and optimize HiPIMS plus kick process parameters for AlN deposition.
• To determine the ideal positive kick bias voltage for high-quality AlN films.
• To evaluate the impact of optimized parameters on film properties like deposition rate, surface smoothness, and thermal conductivity.

Main Methods:

• Utilized high-power impulse magnetron sputtering (HiPIMS) with bipolar voltage pulsing (kick biasing).
• Conducted systematic parameter variation, focusing on optimized main negative pulsing and positive kick bias.
• Characterized deposited AlN films using X-ray diffraction (XRD), transmission electron microscopy (TEM), and thermal conductivity measurements.

Main Results:

• Identified 25 V as the optimal positive kick bias for AlN deposition under specific pulsing conditions.
• Achieved high-speed deposition at 25 nm/min with ultrasmooth surfaces (rms roughness = 0.5 nm).
• Deposited a highly oriented, single-texture 1 μm AlN film (7.4° rocking curve) with excellent thermal conductivity (121 W/m·K).

Conclusions:

• Optimized HiPIMS plus kick, with a 25 V positive kick bias, enables high-quality AlN film deposition.
• The optimal kick voltage enhances surface diffusion without causing significant ion damage to AlN grains.
• This technique offers a promising route for high-performance AlN films with superior thermal properties.