The thermal conductivity was largely lowered by SiO2-doping because thermal conduction by phonon vibration is sensitive to microstructure. SiO2-doped Ge2Sb2Te5 was observed to have a layered structure resulting from the inhomogeneous distribution of SiO2 after annealing.

In order to clarify the influence of SiO2-doping on device performance, the team fabricated a test cell and performed electrical characterization on the PcRAM device.

Electro-thermal simulation revealed that the reduced thermal conductivity contributes to the improvement in cell efficiency as well as to a reduction in the reset current. In addition, the SiO2-doped GST has a large sensing margin comparable to that of GST, which is usually unexpected from other dopants, such as O, N and Si.

More information can be found in the journal Nanotechnology.