Patent ID: 7906170

Claim:
An apparatus capable of producing a moveable magnetic field, the apparatus comprising: a moveable support structure; a semiconductor wafer supported by and held within a plane of the moveable support structure, the semiconducting wafer having a first side and an opposing second side; and a magnetic field source directly attached to and in a fixed position relative to the moveable support structure such that it moves in tandem with the moveable support structure, wherein: the magnetic field source comprises a first permanent magnetic bar located at the first side of the semiconducting wafer and a second permanent magnetic bar located at the second side of the semiconducting wafer; the first permanent magnetic bar has a first axis with a north pole at a first end thereof and a south pole at an opposing second end thereof; the second permanent magnetic bar has a second axis with a north pole at a first end thereof and a south pole at an opposing second end thereof; the first permanent magnetic bar and the second permanent magnetic bar are aligned in attraction with each other; the first permanent magnetic bar has a first height and a first depth and the second permanent magnetic bar has a second height and a second depth; the semiconducting wafer has a third height and a third depth; the first height and the second height are each at least as great as the third height; the first depth and the second depth are each at least as great as the third depth; the magnetic field source generates a magnetic field of at least 50 Oersted; and the magnetic field is aligned so as to produce magnetic anisotropy in the plane of the moveable support structure.