A method of writing to magnetic random access memory (MRAM) devices is
provided. The method includes preparing a digit line disposed on a
semiconductor substrate, a bit line crossing over the digit line, and a
magnetic tunnel junction (MTJ) interposed between the digit line and the
bit line. The MTJ has a pinned layer, a tunneling insulating layer, and a
synthetic anti-ferromagnetic (SAF) free layer which are sequentially
stacked. In addition, the SAF free layer has a bottom free layer and a
top free layer which are separated by an exchange spacer layer. An
initial magnetization state of the MTJ is read and compared with a
desired magnetization state. When the initial magnetization state is
different from the desired magnetization state, a first write line pulse
is applied to one of the digit line and the bit line, and a second write
line pulse is applied to the other of the digit line and the bit line,
thereby changing the magnetization state of the MTJ. The MTJ may be
disposed at an angle equal to or greater than 0.degree. and less than
90.degree. to a line to which the second write line pulse is applied.