Measuring and analyzing electrical resistance in tunneling magnetoresist sensors to identify damaged sensors

A computer program product comprising:

• a non-transitory computer readable storage medium;
• and
• computer code stored on the non-transitory computer readable storage medium, with the computer code including instructions for causing a processor to perform operations including the following:
• applying, one or both of negative polarity current and positive polarity current to a first contact and a second contact of a first tunneling magnetoresistance (TMR) sensor at a first plurality of current magnitudes, where the first plurality of current magnitudes comprises at least three current magnitudes and the current traverses a plurality of layers of the first TMR sensor;
• determining resistances of the first TMR sensor based, at least in part, on the application of one or both of negative polarity current and positive polarity current;
• calculating a slope and a zero-current intercept for the determined resistances of the first TMR sensor at the first plurality of current magnitudes;
• determining whether at least one of the calculated slope and the zero-current intercept are outside of a specified range of values;
• and
• responsive to determining that at least one of the calculated slope and the zero-current intercept are outside of the specified range of values, identifying the first TMR sensor as damaged;
• wherein the one or both of negative polarity current and positive polarity current interact with defects in the first TMR sensor when applied to the first TMR sensor to influence the determined resistances.

A computer system comprising:

• one or more computer processors;
• one or more non-transitory computer readable storage media;
• program instructions stored on the non-transitory computer readable storage media for including instructions for causing the one or more computer processors to perform operations including the following:
• applying, one or both of negative polarity current and positive polarity current to a first contact and a second contact of a first tunneling magnetoresistance (TMR) sensor at a first plurality of current magnitudes, where the first plurality of current magnitudes comprises at least three current magnitudes and the current traverses a plurality of layers of the first TMR sensor;
• determining resistances of a the first TMR sensor based, at least in part, on the application of one or both of negative polarity current and positive polarity current;
• calculating a slope and a zero-current intercept for the determined resistances of the first TMR sensor at the first plurality of current magnitudes;
• determining whether at least one of the calculated slope and the zero-current intercept are outside of a specified range of values;
• and
• responsive to determining that at least one of the calculated slope and the zero-current intercept are outside of the specified range of values, identifying the first TMR sensor as damaged;
• wherein the one or both of negative polarity current and positive polarity current interact with defects in the first TMR sensor when applied to the first TMR sensor to influence the determined resistances.