Highly scalable on-axis confined cell structure for high density PRAM beyond 256Mb

Phase change memories: State-of-the-art, challenges and perspectives

“…An in-situ deposition/etch/ deposition method is able to overcome this difficulty. Deposition of the GST within a 50 nm pore with a 1:2 aspect ratio has been reliably demonstrated and is able to reduce the programming current to 400 lA [24].…”

Thermal Stability of SiO2Doped Ge2Sb2Te5for Application in Phase Change Random Access Memory

“…2(a). Layer density of as-deposited GST is 72.48 μg/cm 2 , from which the density of as-deposited GST film can be calculated to be 4.83 g/cm 3 . It is approximately 17% lower than the previously reported one by X-ray reflectance (XRR) [20].…”

“…Phase change random access memory (PCRAM) is a promising candidate for next generation non-volatile memory devices not only because it satisfies various demands for non-volatile memory devices, but also because its fabrication process is relatively simple [1][2][3]. PCRAM is operated by reversibly changing the phase between the crystalline and amorphous state of chalcogenide materials, such as Ge 2 Sb 2 Te 5 (GST), brought by joule heating.…”

“…In PCRAM cells, the reversible switching between these two states can be achieved by applying a short (~ 50 ns) and high current pulse (I res ~ 1 mA) for the transition from the crystalline to the amorphous state (reset process) and a relatively long (I set ~ 100 ns) and low current pulse (~ 0.2 mA) for switching from the amorphous to the crystalline state (set process). [3,4] However, the high level of reset current (I res ) has been a major obstacle to the further scaling of PCRAM, because of the limited on-current drive capability of the cell transistor (< 0.5 mA/μm). There have been various investigations on the improvement of the switching performance of GST [5][6][7][8][9][10][11][12].…”

Application of ordered mesoporous SiO2 film for low power consumption in phase-change memory

“…Low thermal conductivity of component materials of PCM would be highly desirable for effective Joule heating and low power consumption [19]. Research in heat management has focused mainly on the control of cell structure [20,21]. In this work, we tried to introduce a dielectric with thermal insulation instead of conventional dielectric in the form of normal SiO 2 .…”