The 9th International Conference on Surface Engineering (ICSE 2024)

The ionization rate of continuous high-power magnetron sputtering (C-HPMS) can reach the level of high-power impulse magnetron sputtering (HiPIMS), and C-HPMS shows more stable discharge and higher deposition efficiency. Through reactive sputtering, efficient preparation of compound coatings can be achieved by C-HPMS. which has good industrial application prospects. However, unlike traditional magnetron sputtering, both the reaction gas and metal are highly ionized during C-HPMS reactive sputtering. The formation and consumption mechanisms of target surface compounds varies with discharge characteristics. Therefore, utilizing the reactive sputtering of Al as an example, the plasma overall model is established to study the target poisoning mechanism during the C-HPMS reactive sputtering process. The results indicate that with the increase of power density, the self-sputtering behavior of metal ions is significantly enhanced. Strong self-sputtering phenomena causes continuously etching of insulation films on target surface, effectively alleviating target poisoning. By using C-HPMS to deposit AlO_x films, the tolerance limit of Al target to O₂/Ar ratio increases from 1.57 (20 W/cm²) to 7.93 (120 W/cm²), significantly expanding the process window. High power density alters the target poisoning mechanism dominated by neutral gas particle adsorption in conventional reactive magnetron sputtering. Under high power density, higher proportion of reaction gas ions participate in the generation of target compounds. Thus, target poisoning becomes jointly dominated by the adsorption of neutral gas particles and the gas ion implement. As the etching channel deepens, the proportion of ion implantation significantly increases, leading to a continuous exacerbation of target poisoning. At high power density (100 W/cm₂), the tolerance limit of Al target to N₂/Ar decreases from 4.76 (target etching depth of 0 mm) to 2.23 (target etching depth of 4.2 mm). The results provide insights into the design of high-power reactive sputtering power sources, thereby promoting the industrial application of reactive C-HPMS.
 

continuous high-power magnetron sputtering (C-HPMS); target poisoning; ion implantation; discharge intensity