Phase Change Memory Selection Element With Metal-Semiconductor Depletion Barrier
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Solution Overview
Problem
The integration of phase change memory devices is hindered by the large area of metal oxide semiconductor (MOS) transistors, making it difficult to achieve high integration due to their relatively large size.
Innovation Solution
A phase change memory device with a selection element comprising a metallic conductor and a semiconductor in contact, featuring a depletion region with a low barrier region and a high barrier region, where the high barrier region has a maximum electric potential barrier spaced apart from the contact surface, and a heat plug connecting the metallic conductor to the phase change material, allowing for efficient data storage and selection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a MOS transistor is used as the selection element, then reliable data selection is achieved, but the device area increases making high integration difficult
Solution Approach 1:
The patent changes the material parameters of the selection element by using a metal-semiconductor contact structure with specifically engineered depletion regions and barrier heights, replacing the conventional MOS transistor structure to achieve smaller area while maintaining selection reliability
Solution Approach 2:
The patent extracts the gate oxide layer and gate electrode from the conventional MOS transistor structure, retaining only the essential selection function through a simplified metal-semiconductor contact with controlled depletion regions, thereby reducing device area
2Object-generated harmful factors
If the depletion region has a high barrier region, then leakage current is minimized, but the threshold voltage increases
Solution Approach 1:
The patent applies local quality by creating a non-uniform depletion region with spatially varying barrier heights - a high barrier region near the metal-semiconductor interface to block leakage, and a low barrier region toward the phase change material to facilitate controlled switching, thus resolving the contradiction between leakage suppression and threshold voltage reduction
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
This configuration enables high-speed operation with low threshold voltage and minimized leakage current, facilitating high integration and reduced power consumption in phase change memory devices.
Implementation Method 1
A depletion region in contact with the metallic conductor is generated in the semiconductor in an equilibrium state. The depletion region may include a low barrier region and a high barrier region.
Implementation Method 2
The phase change material may change into a crystallization state or an amorphous state according to a heat temperature and/or a heat supply time.
Implementation Method 3
The phase change material may change into a crystallization state or an amorphous state according to a heat temperature and/or a heat supply time.
Implementation Method 4
a heat plug connecting the metallic conductor to the phase change material
Data Source
AI summary
Phase change memory devices are provided including a selection element electrically connected to a phase change material pattern. The selection element includes a metallic conductor and a semiconductor that are in contact with each other. A depletion region in contact with a metallic pattern is generated in the semiconductor in an equilibrium state. The depletion region includes a high barrier region having an electric potential barrier higher than an interface electric potential barrier and a low barrier region having an electric potential barrier lower than the interface electric potential barrier. Related methods are also provided.