Enhanced write performance of a 64-mb phase-change random access memory

The write performance of the 1.8-V 64-Mb phase-change random access memory (PRAM) has been improved, which was developed based on 0.12-/spl mu/m CMOS technology. For the improvement of RESET and SET distributions, a cell current regulator scheme and multiple step-down pulse generator were employed, respectively. The read access time and SET write time are 68 ns and 180 ns, respectively.