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AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsCheng-Wei Chien, Harry-Hak-Lay Chuang, Kuei-Hung Shen, Kuo-Feng Huang, Bo-Hung Lin, Chun-Chi Chen
Estimating the term…
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.
A system, comprising:
A method of characterizing a wafer containing dies having magnetic random access memory (MRAM) devices, the method comprising:
A processor implemented controller for an equipment front end module (EFEM) having a first magnet, a second magnet, a chip probe, and a mechanical device configured to move a wafer relative to the first magnet and the second magnet, the controller comprising a processor circuit configured to perform operations comprising:
Dependencies are inferred from the claim text.