Method for Fabricating Inductors with Deposition-Induced Magnetically-Anisotropic Cores

A method of fabricating an inductor, the method comprising:

• forming a ferromagnetic core on a semiconductor substrate, the ferromagnetic core lying in a core plane;
• fabricating an inductor coil that winds around the ferromagnetic core, the inductor coil configured to generate an inductor magnetic field that passes through the ferromagnetic core in a first direction parallel to the core plane;
• and
• while forming the ferromagnetic core:
• with a bias permanent magnet, producing a bias magnetic field that passes through the magnetic core in a second direction that is orthogonal to the first direction;
• and
• inducing a magnetic anisotropy in the ferromagnetic core with the bias magnetic field.

A method of fabricating a planar magnetic core, the method comprising:

• depositing a ferromagnetic material on a semiconductor substrate;
• and
• while depositing the ferromagnetic material:
• generating a bias magnetic field that passes through the magnetic ferromagnetic material in a first direction;
• and
• inducing a magnetic anisotropy in the ferromagnetic material, with the bias magnetic field;
• and
• defining a pattern in the ferromagnetic material to form the planar magnetic core, the planar magnetic core having the magnetic anisotropy.