Hitachi and Renesas jointly launched phase transition memory prototype

Hitachi (Hitachi Ltd.) and Renesas Technology (Renesas Technology) days ago released successful prototype low power phase conversion memory unit. The nonvolatile semiconductor memory cell can be programmed under the condition that the supply voltage is 1.5V and the current is as low as 100 A. Compared with the previous release technology Hitachi and Renesas products, power consumption of each unit was reduced by 50%.

According to the introduction, compared with the existing non-volatile memory, new phase conversion unit in high speed reading and writing ability, programming durability, small size and high level of integration are more excellent. Therefore, these prototypes can be in the next generation of micro controller for information such as equipment, household appliances, and on-board equipment and control system of embedded applications on chip programming and data storage solutions provide a promising.

The prototype unit using 130nm CMOS manufacturing process, the structure of the MOS transistor and a layer of a non crystal state in response to heat (Gao Zukang) or crystalline (low impedance) phase conversion film. The programming of the two states is realized by the 180nm tungsten electrode contact (BEC). In a read operation, the stored digital (1 or 0) information is determined by the difference in the amount of current flowing in the film.

In order to obtain the effect of power breakthrough, Hitachi researchers and Renesas developed an original programming ability with low voltage low current phase conversion film. They used a controlled germanium antimony tellurium (GeSbTe) - doped material to produce the film. Oxygen doping can limit the impedance of the phase change film to an ideal level, while suppressing excessive current flow during programming. In addition, the implementation of the unit can reduce the gate width of the MOS transistors forming these units, and drive the number of output MOS transistors, thereby helping to reduce the size of the memory cell and the drive circuit.