Achieving Compact Structure and Good Mechanical Properties of AlN Thin Film through Low Temperature HiPIMS

Thin films of aluminium nitride (AlN) were successfully deposited using the High Power Impulse Magnetron Sputtering (HiPIMS) technique at room temperature. X-ray diffraction (XRD) analysis confirmed a hexagonal close-packed (hcp) AlN crystal structure in the films. Notably, a highly pronounced orientation along the (002) plane was observed at the lowest sputtering pressure of 3 mTorr, while higher pressures led to the formation of a polycrystalline structure. The films deposited at 3 mTorr exhibited a dense and pebble-like morphology, resulting in impressive mechanical properties. The measured mechanical hardness was determined to be 17 GPa, and the Young's modulus was found to be 187 GPa. By reducing the sputtering pressure, the crystal quality, surface morphology, and mechanical properties of the films were observed to improve. This study demonstrates the potential of the HiPIMS technique to produce high-quality thin films at low temperatures, opening opportunities for various applications in fields such as electronics, optoelectronics, and materials science. The findings highlight the importance of process parameters in tailoring the properties of thin films for specific applications, paving the way for further advancements in thin film technology.