Ultra-low loss on-chip magnetic inductors in the far-BEOL for high frequency power electronics

In this paper we present ultra-low loss magnetic inductors integrate-able in the far BEOL across technology nodes for power management applications such as DC-DC convertors. Our inductors have inductance densities as high as 158 nH/mm
²
up to 100 MHz, Q factors >20 and a high saturation current of 1.77 A in ≤ 1mm
²
area with 50 μm thickness. The inductors also maintain a Q factor >10 after considering the large signal losses, which makes them suitable for handling high DC load currents and large AC ripples at high frequencies, such as in integrated voltage regulators. This is possible by using a highly optimized laminated magnetic material as core that enables very high saturation current and ultra-low losses. Hence, our inductors can replace the existing on-board, bulky and lossy inductors in power convertors including voltage regulators for CPUs/GPUs.