MULTI-LEVEL PHASE CHANGE MEMORY DEVICE AND WRITE METHOD THEREOF

摘要

A multi-level phase change memory device and write method thereof is provided to secure a read margin between the states which are adjacent by supplying the post write current, and the write current. In a multi-level phase change memory device, a resistor unit comprises a phase conversion film consisting of the GST material, and each memory cell is the rewritable memory cell. A row selection circuit(220) selects at least one of rows in response to the row address, and the column selecting circuit(230) selects a part of columns in response to the column address. A control logic(240) controls whole operations of the multi-level phase change memory device(200) in response to the outside reading / write command.