Magnetic field transducer mounting methods for MTJ device testers

1. A method of controlling a magnetic field of a wafer test fixture magnet comprising:

measuring a magnetic field generated by the wafer test fixture magnet during testing of a wafer of Magnetoresistive Tunnel Junction (MTJ) devices using a first magnetic field transducer positioned, by a magnetic field transducer mounting apparatus, in a predetermined location adjacent a face of the wafer test fixture magnet; and

controlling the magnetic field generated by the wafer test fixture magnet based on the measurement of the magnetic field at the first magnetic field transducer during the testing of the wafer of MTJ devices.

2. The method according to claim 1 , further comprising:

measuring a set of one or more magnetic fields generated by a wafer test fixture magnet using the first magnetic field transducer positioned, by the magnetic field transducer mounting apparatus, in the predetermined location adjacent the face of the wafer test fixture magnet;

measuring the set of one or more magnetic fields generated by the wafer test fixture magnet using a second magnetic field transducer positioned proximate a wafer chuck where the wafer of MTJ devices are positioned during testing;

correlating the set of one or more magnetic fields measured at the face of the wafer test fixture magnet to the set of one or more magnetic fields measure at the wafer check; and

controlling the magnetic field generated by the wafer test fixture magnet further based on the measurement of the magnetic field at the first magnetic field transducer and the correlation between the set of one or more magnetic fields measured at the wafer test fixture magnet to the set of one or more magnetic fields measure at the wafer chuck during the testing of the wafer of MTJ devices.

3. The method according to claim 1 , wherein,

the wafer test fixture magnet comprises an electromagnet; and

the wafer of MTJ device comprises a wafer of Spin Torque Magnetoresistive Random-Access Memory (ST-MRAM) devices.

4. The method according to claim 1 , further comprising:

fixedly coupling a first mounting portion of a first non-magnetic element of the magnetic field transducer mounting apparatus to a side surface of the wafer test fixture magnet;

wherein a spacer portion of the first non-magnetic element fixedly positions a second mounting portion of the first non-magnetic element a predetermined distance from the first mounting portion adjacent a side surface of the wafer test fixture magnet;

coupling the magnetic field transducer to one or more surfaces of a second non-magnetic element; and

coupling a third mounting port of the second non-magnetic element to the second mounting portion; and

adjustably positioning the magnetic field transducer in a predetermined position adjacent a face of the wafer test fixture magnet.

5. A method comprising:

fixedly coupling a first mount of a first elongated portion of a magnetic transducer mounting apparatus to a side surface of a wafer test fixture magnet;

coupling a second mount of a second elongated portion of the magnetic transducer mounting apparatus to a third mount of a third elongated portion of the magnetic transducer mounting apparatus, wherein the second elongated portion is disposed transverse to the first elongated portion in a first plane, and the second elongated portion is disposed transverse to the third elongated portion in a second plane, wherein the first plane is transverse to the second plane;

adjusting the second and third mount to position a magnetic field transducer in a predetermined position adjacent a face of the wafer test fixture magnet;

measuring a magnetic field generated by the wafer test fixture magnet during testing of a wafer of Magnetoresistive Tunnel Junction (MTJ) devices using the first magnetic field transducer positioned, by the magnetic field transducer mounting apparatus; and

controlling the magnetic field generated by the wafer test fixture magnet based on the measurement of the magnetic field at the first magnetic field transducer during the testing of the wafer of MTJ devices.

6. The method according to claim 5 , wherein fixedly coupling the first mounting portion of the first non-magnetic element to the side surface of the wafer test fixture includes:

engaging a plurality of fasteners passing through respective ones of a plurality of holes of the first mount with a side surface of the wafer test fixture.

7. The method of claim 5 , wherein coupling the second mount of a second elongated portion to the third mount of a third elongated portion and adjusting the second and third mount to position the magnetic field transducer in a predetermined position comprises:

engaging a plurality of threaded fasteners passing through a slot of the third mound in threaded holes in the second mount.

8. The method according to claim 5 , wherein coupling the second mount of a second elongated portion to the third mount of a third elongated portion and adjusting the second and third mount to position the magnetic field transducer in a predetermined position comprises

matting a first one of a dovetail on the third mount to a second one of a dovetail on the second mount; and

engaging a threaded fastener through a threaded hole in the first dovetail of the third mount to the second mount.

9. The method according to claim 5 , further comprising:

fixedly coupling the magnetic field transducer to a surface of the third elongated portion distal from the third mount and transverse to the face of the wafer test fixture magnet.

10. The method according to claim 5 , wherein,

the wafer test fixture magnet comprises an electromagnet; and

the wafer of MTJ device comprises a wafer of Spin Torque Magnetoresistive Random-Access Memory (ST-MRAM) devices.