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

Abstract

Phase transform properties of Indium Selenide (In 2 Se 3 ) 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 (Ge 2 Sb 2 Te 5 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 (In 2 Se 3 ) material and also draws comparison with its counterpart mainly focusing on phase transform properties. To achieve this goal, a SPICE model of In 2 Se 3 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 μ A for a duration of 100 μ s to set the PCRAM in crystalline state. Similarly, a reset pulse of 11.7 μ A for a duration of 20 ns can set the PCRAM in amorphous state. Modeling of In 2 Se 3 based PCRAM has been done in Verilog-A and simulation results have been extensively verified using SPICE simulator.