Transportation Effects and Uniformity Control in Magnetized Capacitively Coupled Plasma

Magnetized Capacitively Coupled Plasmas (MCCPs) are widely employed in applications of significant societal importance, including semiconductor manufacturing, solar cell production, and environmental technologies. This study investigates the fundamental mechanisms governing electron dynamics and transport phenomena in MCCP systems operating at ultra-low pressures (<10 mTorr), with a focus on achieving plasma uniformity.



At low pressures, the radial plasma density distribution typically exhibits a pronounced peak at the chamber center, diminishing toward the periphery. Such non-uniformity imposes critical limitations on industrial processes, leading to distorted ion angular distributions and radial variations in etch or deposition rates. To overcome these challenges, we present a novel magnetic field engineering approach utilizing a direct current (DC) coil positioned above the chamber. This configuration generates a non-uniform static magnetic field that enhances the transport of plasma species toward the electrode periphery, thereby modulating the radial plasma density distribution.



Furthermore, we introduce an innovative dual-coil design comprising an outer and an inner DC coil. The outer coil, with a larger radius, is positioned above the chamber, while the inner coil—placed either above or below—has a smaller radius. Crucially, the currents in the two coils flow in opposite directions. Our findings reveal that the outer coil primarily dictates the global plasma density distribution across the electrode surface, whereas the inner coil enables fine-tuned control over the plasma density near the discharge center. This dual-coil configuration offers unprecedented precision in plasma manipulation, which is essential for the fabrication of high-aspect-ratio microelectronic structures.