Nonvolatile Memory Cell With Channel Isolation Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional nonvolatile memory devices face limitations in increasing integration density due to the need for multiple transistors and complex fabrication processes, particularly in applying high voltages for programming operations, which restricts the density of memory cells.
Innovation Solution
A nonvolatile memory device with a metal-oxide-semiconductor (MOS) transistor having an insulating isolation layer in the channel region, allowing for a single transistor to store 1-bit or 2-bit data, and a method of fabricating this device using shallow trench isolation and specific doping techniques to form diode structures for data storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple transistors are used per memory cell to enable high-voltage programming operations, then the reliability of data storage is improved, but the integration density of the memory device deteriorates
Solution Approach 1:
The patent combines multiple transistor functions into a single transistor by forming an insulating isolation layer within the channel region. This single transistor performs both the access function and the high-voltage programming function, eliminating the need for separate transistors and thereby improving integration density while maintaining data storage reliability.
Solution Approach 2:
The patent introduces a vertical dimension by forming an insulating isolation layer within the channel region of the transistor. This three-dimensional structure allows the single transistor to achieve functions that traditionally required multiple planar transistors, thus improving area efficiency while maintaining reliability.
2Adaptability or versatility
If multiple transistors and complex fabrication processes are used, then the functionality of high-voltage programming is achieved, but the device complexity increases
Solution Approach 1:
The patent merges multiple transistor functions into a single transistor structure with an insulating isolation layer in the channel. This consolidation reduces the number of fabrication steps and structural elements while maintaining the high-voltage programming capability, thereby reducing device complexity.
Solution Approach 2:
The patent changes the electrical parameters of the single transistor by introducing an insulating isolation layer in the channel region, which enables high-voltage programming capability without requiring additional transistors or complex circuit configurations, thus simplifying the overall device structure.
3Area of moving object
If a single transistor is used per memory cell to increase integration density, then the area efficiency is improved, but the capability to perform high-voltage programming operations deteriorates
Solution Approach 1:
The patent modifies the electrical parameters of the single transistor by forming an insulating isolation layer within the channel region. This structural modification enables the transistor to withstand and perform high-voltage programming operations, thus maintaining programming capability while achieving high integration density.
Solution Approach 2:
The patent utilizes a vertical structure by forming an insulating isolation layer within the channel region, allowing the single transistor to achieve high-voltage programming capability that would traditionally require multiple transistors, thereby maintaining functionality while improving area efficiency.
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 approach enables higher integration density and simplifies the fabrication process by using a single transistor per memory cell, improving data storage efficiency and reducing the complexity of high-voltage operations.
Implementation Method 1
An insulating isolation layer is formed in a region including a channel region between the source and drain regions in the semiconductor substrate
Implementation Method 2
when a high voltage for a program operation is applied between insulating layers or variable resistors serving as storage layers, resistances of the insulating layers or the variable resistors vary
Data Source
AI summary
The nonvolatile memory device includes a memory cell having a transistor in which an insulating isolation layer is formed in a channel region. The nonvolatile memory device includes a metal-oxide-semiconductor (MOS) transistor as a basic component. An insulating isolation layer is formed in at least a channel region, and a gate insulating layer includes an insulating layer or a variable resistor and serves as a data storage. A gate includes a metal layer formed in a lower portion thereof. First source and drain regions are lightly doped with a dopant, and second source and drain regions are heavily doped with a dopant.