MAGNET CONFIGURATION SYSTEMS AND METHODS TO DETECT MAGNETIC TUNNEL JUNCTION COERCIVITY WEAK BITS IN MRAM CHIPS

Disclosed methods include placing a semiconductor wafer containing MRAM devices into a first magnetic field that has a magnitude sufficient to magnetically polarize MRAM bits and has a substantially uniform field strength and direction over the entire area of the wafer. The method further includes placing the wafer in a second magnetic field having an opposite field direction, a substantially uniform field strength and direction over the entire area of the wafer, and magnitude less than a design threshold for MRAM bit magnetization reversal. The method further includes determining a presence of malfunctioning MRAM bits by determining that such malfunctioning MRAM bits have a magnetic polarization that was reversed due to exposure to the second magnetic field. Malfunctioning MRAM bits may further be characterized by electrically reading data bits, or by using a chip probe to read one or more of voltage, current, resistances, etc., of the MRAM devices.