Single Gate Semiconductor Memory Device for Low Voltage Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing single gate semiconductor memory devices face challenges in operating stably in a low voltage environment, have larger cell sizes due to the need for separate N-well and deep N-well structures, and suffer from instability and increased peripheral circuit size, making them unsuitable for mass storage applications.
Innovation Solution
A semiconductor memory device with a single gate structure that includes a first and second conductive type well, gates, and ion implantation regions, where the second conductive type ion implantation regions are connected to form a series structure, allowing for stable operation in a low voltage environment and minimizing cell size and peripheral circuit size by preventing latch-up phenomena.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a deep N-well structure is formed to separate the P-well from the semiconductor substrate, then the semiconductor memory device can operate when the substrate is biased to negative electric potential, but the cell size becomes greater and the operation becomes unstable
Solution Approach 1:
The invention merges the deep N-well separation function into the P-well structure itself by forming a first conductive type well (P-well) that extends deeply into the substrate. This eliminates the need for a separate deep N-well structure while maintaining the ability to operate with negative substrate bias, thereby reducing cell size while preserving operation stability.
Solution Approach 2:
The P-well structure is designed to serve multiple functions: it acts as both the transistor well and the deep separation structure simultaneously. By making the P-well extend deeply into the substrate, it performs both the transistor formation function and the substrate separation function, eliminating the need for additional structures and reducing overall cell size.
2Ease of manufacture
If the N-well is separated from the deep N-well, then the semiconductor memory device can be realized, but the operation becomes unstable
Solution Approach 1:
The invention combines the N-well and deep N-well into a single continuous N-well structure that extends from the surface to the substrate. This eliminates the separation between N-well and deep N-well, ensuring stable operation while maintaining ease of manufacture through a simplified single-well architecture.
3Reliability
If the N-well is separated from the deep N-well in the direction of the bit line, then the floating gate can be induced to specific electric potential, but the cell size becomes greater
Solution Approach 1:
The invention merges the N-well structures and optimizes their spatial arrangement to provide adequate separation for gate induction functionality while minimizing the overall cell footprint. The continuous N-well structure maintains the necessary electric potential induction capability without requiring excessive lateral separation.
4Ease of manufacture
If a single gate structure is used, then the manufacturing process is simplified, but the device cannot operate stably in low voltage environment due to latch-up phenomena
Solution Approach 1:
The invention combines P-type and N-type ion implantation regions within the single gate structure to create inherent latch-up prevention mechanisms. By integrating both conductive type regions appropriately, the structure prevents parasitic transistor formation while maintaining manufacturing simplicity.
Solution Approach 2:
The invention changes the electrical parameters by introducing specifically doped ion implantation regions with controlled conductivity types and concentrations. These parameter changes modify the electrical characteristics to prevent latch-up phenomena while maintaining low voltage operation capability.
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 solution enables stable program and read operations in a low voltage environment, minimizes cell size, and simplifies the peripheral circuit, enhancing integration and preventing latch-up issues, thus making the semiconductor memory device more suitable for mass storage applications.
Implementation Method 1
a second conductive type first ion implantation region disposed in the first conductive type well at one side of the first gate; a second conductive type second ion implantation region disposed in the first conductive type well at the other side of the first gate; a first conductive type first ion implantation region disposed in the second conductive type well at one side of the second gate; a first conductive type second ion implantation region disposed in the second conductive type well at the other side of the second gate
Data Source
AI summary
A semiconductor memory device and a method of manufacturing the same. The semiconductor memory device includes a first conductive type well and a second conductive type well disposed on and/or over a semiconductor substrate; a first gate and a second gate disposed on and/or over the first conductive type well and the second conductive type well, respectively; a second conductive type first ion implantation region disposed in the first conductive type well at one side of the first gate and a second conductive type second ion implantation region disposed in the first conductive type well at the other side of the first gate; a first conductive type first ion implantation region disposed in the second conductive type well at one side of the second gate and a first conductive type second ion implantation region disposed in the second conductive type well at the other side of the second gate; and a line electrically connecting the second conductive type second ion implantation region with the first conductive type first ion implantation region.