THERMAL EXPANSION OF PHASE-CHANGE RANDOM ACCESS MEMORY CELLS

2008 ◽  
Vol 1072 ◽  
Author(s):  
Jianming Li ◽  
L.P. Shi ◽  
H.X. Yang ◽  
K.G. Lim ◽  
X.S. Miao ◽  
...  

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.

2007 ◽  
Vol 124-126 ◽  
pp. 37-40 ◽  
Author(s):  
Sung Soon Kim ◽  
Jun Hyun Bae ◽  
Woo Hyuck Do ◽  
Kyun Ho Lee ◽  
Young Tae Kim ◽  
...  

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.


2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Swapnil Sourav ◽  
Amit Krishna Dwivedi ◽  
Aminul Islam

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.


Author(s):  
Sung Soon Kim ◽  
Jun Hyun Bae ◽  
Woo Hyuck Do ◽  
Kyun Ho Lee ◽  
Young Tae Kim ◽  
...  

2007 ◽  
Vol 7 (1) ◽  
pp. 298-305 ◽  
Author(s):  
Dae-Hwang Kim ◽  
Florian Merget ◽  
Michael Först ◽  
Heinrich Kurz

The RESET operation of different design concepts for phase change random access memory (PCRAM) cell is studied and compared using a three dimensional simulation model. This numerical algorithm comprises four interacting sub-models, which describe the electrical, thermal, phase change, and percolation dynamics in the PCRAM devices during the switching operation. The so-called vertical, confined, and lateral cell geometries are evaluated in terms of their current requirements for RESET operations, which is one of the most critical issues for an achievement of high integration densities. The advantages of the confined and lateral cell architecture as compared to the conventional vertical cell concept are explored, demonstrating their benefits of advanced thermal management and minimized current defined area. The simulation results agree well with experimental features of the RESET operation for the PCRAM design concepts studied.


Nanoscale ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 4678-4684
Author(s):  
Yan Cheng ◽  
Yonghui Zheng ◽  
Zhitang Song

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.


2010 ◽  
Vol 13 (2) ◽  
pp. K8 ◽  
Author(s):  
Dongbok Lee ◽  
Sung-Soo Yim ◽  
Ho-Ki Lyeo ◽  
Min-Ho Kwon ◽  
Dongmin Kang ◽  
...  

2006 ◽  
Vol 45 (5A) ◽  
pp. 3955-3958 ◽  
Author(s):  
X. S. Miao ◽  
L. P. Shi ◽  
H. K. Lee ◽  
J. M. Li ◽  
R. Zhao ◽  
...  

2005 ◽  
Vol 98 (1) ◽  
pp. 013520 ◽  
Author(s):  
V. Giraud ◽  
J. Cluzel ◽  
V. Sousa ◽  
A. Jacquot ◽  
A. Dauscher ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document