Magnetic circuit design and magnetic field uniformity optimization of a magnetron sputtering system for large-size inclined substrates

The fast-growing display industry demands coatings on increasingly large glass substrates. Conventional vertical magnetron sputtering requires a substrate carrier, which raises equipment cost and wastes material in carrier-covered regions. A carrier-free inclined-substrate configuration (85° inclination), therefore, offers higher material utilization and lower cost. This work presents the magnetic-circuit design and field-uniformity optimization of a large-area rectangular magnetron sputtering target for such substrates. The magnetic flux density between the target and the substrate is obtained from an analytical magnetic-charge integration model and compared with 3D magnetostatic COMSOL simulations using the “Magnetic Fields, No Currents” interface for N42 NdFeB magnets (1.3 T remanence). The straight section is optimized parametrically through flux-concentrating/guiding structures and magnet dimensions, and the end region is evaluated across four configurations. The adopted end design (a semicircular inner strip plus a semitoroidal outer ring) reduces the maximum curve separation Sm—the maximum lateral distance between the end-region and straight-section field curves—from 143 to 12.5 mm (a 91.3% reduction), while the peak horizontal flux density, measured at the cathode-sheath height along the erosion-zone centerline, changes from 58.3 to 54.7 mT. The 54.7 mT peak lies marginally above the 30–50 mT engineering target range and should be brought back into the interval in a subsequent refinement. This is a computational study; the predicted fields and the anticipated process benefits require experimental validation.