Thermal Stress Model for Phase Change Random Access Memory

Thermal stress model considering the effect of phase transformation is proposed for Phase-Change Random Access Memory (PRAM). The results of simulation show that the high level of stress is generated on the junction where Ge2Sb2Te5(GST), TiN and SiO2 meet together. The high level of stress can also be observed in the interface between TiN and SiO2. From simulation results, it can be predictable that delamination between GST and TiN can occur during operation of PRAM. It is expected that the simulation model, which has been developed in this research, is very useful tool for PRAM device design.

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Thermal Stress Model for Phase Change Random Access Memory

Solid State Phenomena - Advances in Nanomaterials and Processing ◽

10.4028/3-908451-31-0.37 ◽

2007 ◽

pp. 37-40

Author(s):

Sung Soon Kim ◽

Jun Hyun Bae ◽

Woo Hyuck Do ◽

Kyun Ho Lee ◽

Young Tae Kim ◽

...

Keyword(s):

Thermal Stress ◽

Phase Change ◽

Random Access ◽

Random Access Memory ◽

Stress Model ◽

Access Memory

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THERMAL EXPANSION OF PHASE-CHANGE RANDOM ACCESS MEMORY CELLS

MRS Proceedings ◽

10.1557/proc-1072-g03-18 ◽

2008 ◽

Vol 1072 ◽

Cited By ~ 2

Author(s):

Jianming Li ◽

L.P. Shi ◽

H.X. Yang ◽

K.G. Lim ◽

X.S. Miao ◽

...

Keyword(s):

Thermal Stress ◽

Phase Change ◽

Electrical Power ◽

Thermal Strain ◽

Three Dimensional ◽

Amorphous State ◽

Random Access ◽

Random Access Memory ◽

Access Memory ◽

Three Dimensional Finite Element

ABSTRACTThree-dimensional finite element method (FEM) is used to solve the thermal strain-stress fields of phase-change random access memory (PCRAM) cells. Simulation results show that thermal stress concentrates at the interfaces between electrodes and phase change layer and it is significantly larger than that within the phase change layer. It has been found that the peak thermal stress is linearly related to the voltage of electrical pulse in the reset process but once amorphous state is produced in the cell, a nonlinear relationship between thermal stress and electrical power exists. This paper reported the change of thermal stress during set process. It was found that the stress decreases significantly due to the amorphous active region during set processes.

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Effect of the Bottom Electrode Contact (BEC) on the phase transformation of N2 doped Ge2Sb2Te 5 (N-GST) in a Phase-change Random Access Memory

MRS Proceedings ◽

10.1557/proc-830-d7.9 ◽

2004 ◽

Vol 830 ◽

Cited By ~ 4

Author(s):

Suyoun Lee ◽

Y. J. Song ◽

Y. N. Hwang ◽

S. H. Lee ◽

J. H. Park ◽

...

Keyword(s):

Phase Transformation ◽

Phase Change ◽

Bottom Electrode ◽

Random Access ◽

Surface Oxidation ◽

Random Access Memory ◽

Access Memory ◽

Electrode Contact ◽

Electrode Metal ◽

Contact Size

With respect to the operation of a Phase-change Random Access Memory (PRAM or PcRAM), we studied the effect of the contact between the electrode metal and the chalcogenide glass, N2 doped Ge2Sb2Te5 in this report. We investigated a change of the resistance-programming current pulse (R-I) curve varying the contact size and the electrode material. Also we tested the surface oxidation of the electrode. We found that the programming current, the resistance of the programmed state (“RESET”) and the erased state (“SET”) were highly dependent on the above parameters. These results are presented and a more effective way to the high density PRAM will be proposed.

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Impact of Thermal Boundary Resistance on Thermoelectric Effects of the Blade-Type Phase-Change Random Access Memory Device

Frontiers in Materials ◽

10.3389/fmats.2021.798398 ◽

2022 ◽

Vol 8 ◽

Author(s):

Xiaojuan Lian ◽

Jinke Fu ◽

Zhixuan Gao ◽

Wang Ren ◽

Xiang Wan ◽

...

Keyword(s):

Phase Transformation ◽

Power Consumption ◽

Phase Change ◽

Random Access ◽

Random Access Memory ◽

Boundary Resistance ◽

Thermal Boundary Resistance ◽

Access Memory ◽

Thermoelectric Effects ◽

Electric Polarity

Phase-change random access memory (PCRAM) is widely regarded as one of the most promising candidates to replace Flash memory as the next generation of non-volatile memories due to its high-speed and low-power consumption characteristics. Recent advent of the blade-type PCRAM with low programming current merit further confirms its prospects. The thermoelectric effects existing inside the PCRAM devices have always been an important factor that determines the phase-transformation kinetics due to a fact that it allows PCRAM to have electric polarity dependent characteristics. However, the potential physics governing the thermoelectric effects for blade-type PCRAM device still remains vague. We establish a three-dimensional (3D) electro-thermal and phase-transformation model to study the influences of thermal boundary resistance (TBR) and device scaling on the thermoelectric effects of the blade-type PCRAM during its “RESET” operation. Our research shows that the presence of TBR significantly improves the electric polarity-dependent characteristics of the blade-type PCRAM, and such polarity-dependent characteristic is found immune to the scaling of the device. It is therefore possible to optimize the thermoelectric effects of the blade-type PCRAM through appropriately tailoring the TBR parameters, thus further lowering resulting power consumption.

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Investigating Phase Transform Behavior in Indium Selenide Based RAM and Its Validation as a Memory Element

Journal of Materials ◽

10.1155/2016/6123268 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7

Author(s):

Swapnil Sourav ◽

Amit Krishna Dwivedi ◽

Aminul Islam

Keyword(s):

Phase Change ◽

Phase Change Materials ◽

Amorphous State ◽

Random Access ◽

Random Access Memory ◽

Indium Selenide ◽

Access Memory ◽

Memory Element ◽

Phase Transform ◽

Simulation Results

Phase transform properties of Indium Selenide (In2Se3) based Random Access Memory (RAM) have been explored in this paper. Phase change random access memory (PCRAM) is an attractive solid-state nonvolatile memory that possesses potential to meet various current technology demands of memory design. Already reported PCRAM models are mainly based upon Germanium-Antimony-Tellurium (Ge2Sb2Te5 or GST) materials as their prime constituents. However, PCRAM using GST material lacks some important memory attributes required for memory elements such as larger resistance margin between the highly resistive amorphous and highly conductive crystalline states in phase change materials. This paper investigates various electrical and compositional properties of the Indium Selenide (In2Se3) material and also draws comparison with its counterpart mainly focusing on phase transform properties. To achieve this goal, a SPICE model of In2Se3 based PCRAM model has been reported in this work. The reported model has been also validated to act as a memory cell by associating it with a read/write circuit proposed in this work. Simulation results demonstrate impressive retentivity and low power consumption by requiring a set pulse of 208 μA for a duration of 100 μs to set the PCRAM in crystalline state. Similarly, a reset pulse of 11.7 μA for a duration of 20 ns can set the PCRAM in amorphous state. Modeling of In2Se3 based PCRAM has been done in Verilog-A and simulation results have been extensively verified using SPICE simulator.

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Phase transformation behaviors of SiO2 doped Ge2Sb2Te5 films for application in phase change random access memory

Applied Physics Letters ◽

10.1063/1.2898719 ◽

2008 ◽

Vol 92 (14) ◽

pp. 142110 ◽

Cited By ~ 34

Author(s):

Seung Wook Ryu ◽

Jin Ho Oh ◽

Jong Ho Lee ◽

Byung Joon Choi ◽

Won Kim ◽

...

Keyword(s):

Phase Transformation ◽

Phase Change ◽

Random Access ◽

Random Access Memory ◽

Access Memory

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Three-dimensional simulation model of switching dynamics in phase change random access memory cells

Journal of Applied Physics ◽

10.1063/1.2710440 ◽

2007 ◽

Vol 101 (6) ◽

pp. 064512 ◽

Cited By ~ 70

Author(s):

Dae-Hwang Kim ◽

Florian Merget ◽

Michael Först ◽

Heinrich Kurz

Keyword(s):

Phase Change ◽

Simulation Model ◽

Three Dimensional ◽

Random Access ◽

Random Access Memory ◽

Memory Cells ◽

Access Memory ◽

Switching Dynamics ◽

Dimensional Simulation

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Reversible switching in bicontinuous structure for phase change random access memory application

Nanoscale ◽

10.1039/d0nr09139a ◽

2021 ◽

Vol 13 (8) ◽

pp. 4678-4684

Author(s):

Yan Cheng ◽

Yonghui Zheng ◽

Zhitang Song

Keyword(s):

Phase Change ◽

Random Access ◽

Random Access Memory ◽

Access Memory ◽

Bicontinuous Structure ◽

Amorphous Si

A 3D nano-bicontinuous structure consisting of a reversible Sb2Te3 phase and amorphous Si phase is visualized. The amorphous Si frame is stable and the Sb2Te3 nano areas switch between the a- and f-structure.

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