抄録
Although few considerations have been made concerning the practical implications of multilevel approaches in memory design, there is a general consensus concerning its applicability in MRAM cells. The memory density can be enormously increased with the adoption of multilevel characteristic. We have previously described a new multilevel GMR MRAM cell[5], but the earlier structure has some problems such as separating the memory level, destructive readout and the use of incomplete pseudo spin valve MRAM mode etc[6]. In this work, the second generation of multilevel MRAM has been proposed. It consists of one sensing layer per storage layer. With the combinations of the storage laywrs, we can separate the memory states, so that the multilevel characteristic can be realized. Due to the use of one sensing layer per storage layer, multilevel MRAM with using the fully developed pseudo spin valve MRAM mode has been proved to be established.
