PCRAM Memory Cell Structure With Filamentary Bottom Electrode
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing phase-change random-access memory (PCRAM) devices face challenges in device scaling-down due to inadequate performance in terms of operating current/voltage, despite having advantages like high speed, low power consumption, non-volatility, and high density.
Innovation Solution
A novel memory structure is proposed to confine heat in PCRAM devices by incorporating a filamentary bottom electrode that functions as a heater, facilitating phase change switching and improving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If existing PCRAM device structures are used, then high speed and low power consumption are achieved, but operating current/voltage requirements remain inadequate for further scaling
Solution Approach 1:
The bottom electrode is segmented into a filamentary structure rather than a continuous layer, concentrating the heating function into a localized region that directly contacts the phase change material, thereby reducing the overall current/voltage requirements while maintaining effective heating
Solution Approach 2:
The filamentary bottom electrode provides localized heating quality where it directly contacts the phase change material, creating a high current density region that efficiently induces phase change without requiring high voltage across the entire device structure
2Quantity of substance
If device scaling-down continues, then high density is improved, but operating current/voltage performance becomes inadequate
Solution Approach 1:
The bottom electrode transitions from a two-dimensional planar structure to a one-dimensional filamentary structure, concentrating the heating function vertically at the interface with the phase change material, which enables effective phase change switching at scaled-down device dimensions
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The filamentary bottom electrode reduces operating current/voltage requirements, enhancing the operational efficiency and performance of PCRAM devices.
Implementation Method 1
incorporating a filamentary bottom electrode that functions as a heater
Implementation Method 2
PCRAM technology is based upon a material that can be either amorphous or crystalline at normal ambient temperatures
Data Source
AI summary
A method of forming a memory device includes the following operations. A first conductive plug is formed within a first dielectric layer over a substrate. A treating process is performed to transform a portion of the first conductive plug into a buffer layer, and the buffer layer caps the remaining portion of the first conductive plug. A phase change layer and a top electrode are sequentially formed over the buffer layer. A second dielectric layer is formed to encapsulate the top electrode and the underlying phase change layer. A second conductive plug is formed within the second dielectric layer and in physical contact with the top electrode. A filamentary bottom electrode is formed within the buffer layer.