A method for fabricating a magnetic material stack on a substrate includes the following steps. A first dielectric layer is formed. A first magnetic material layer is formed on the first dielectric layer. At least a second dielectric layer is formed on the first magnetic material layer. At least a second magnetic material layer is formed on the second dielectric layer. During one or more of the forming steps, a surface smoothing operation is performed to remove at least a portion of surface roughness on the layer being formed. The magnetic material stack can be used to form a low magnetic loss yoke inductor.