Integrated On-Chip Inductors With Magnetic Films

On-chip inductors with 2 levels of magnetic material were integrated into an advanced 130-nm CMOS process to obtain over an order of magnitude increase in inductance (19times) and Q-factor (16times), significantly greater than prior values of les2.3times for high frequency inductors. The magnetic material enhances inductance at frequencies up to 9.8 GHz. Measurements and models of the permeability from amorphous CoZrTa alloy demonstrate that the skin effect and eddy current dampening become important. Two levels of magnetic material with high-temperature and long annealing-time stability, high saturation magnetization, low magnetostriction, high resistivity, minimal hysteretic loss, and compatibility with Si technology were used in combination with magnetic vias and elongated structures that take advantage of the uniaxial magnetic anisotropy