Magnetic memory devices having patterned heater layers therein that utilize thermally conductive sidewall materials to increase heat transfer when writing memory data

An integrated circuit memory device, comprising:

• an array of magnetic random access memory (MRAM) cells, said array comprising at least one memory cell having a free layer therein with a variable magnetic orientation, said free layer covered on a first side by a patterned heater layer, which is configured to heat the first side of said free layer in response to connecting the patterned heating layer to a power source in advance of writing data into the at least one memory cell, and covered on second and third opposing sides by thermally conductive and electrically insulating materials, which are configured to transfer heat from the patterned heater layer to sidewalls of the free layer.