Semiconductor Memory Device Local Charge Portions Low Voltage Operation
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Solution Overview
Problem
Conventional semiconductor memory devices face challenges in operating at low voltage and high speed while maintaining high production yield, due to difficulties in achieving sufficient reading current margins and requiring complex reference cells and high precision in bit line voltage control.
Innovation Solution
The implementation of a nonvolatile semiconductor memory device with multiple local charge portions capable of storing static charges in complementary states, allowing for increased reading current margins and operation at low voltage without the need for a reference cell, and enabling high-speed data reading and writing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional reference cells and high precision bit line voltage control are used, then reading current margin is improved, but device complexity and manufacturing precision requirements increase
Solution Approach 1:
The invention extracts and eliminates the reference cell from the memory device structure. By using local charge portions within each memory cell to directly generate reading current, the patent removes the need for separate reference cells, thereby reducing device complexity while maintaining sufficient reading current margin through the complementary charge storage mechanism
Solution Approach 2:
The memory cell uses its own local charge portions to generate the reading current needed for operation. The first and second local charge portions store complementary charges that directly produce the reading current when activated, allowing the memory cell to be self-sufficient without requiring external reference cells or high precision voltage control circuits
2Manufacturing precision
If conventional memory cells are used, then manufacturing precision requirements increase, but production yield decreases
Solution Approach 1:
The invention uses simple local charge portions that can be easily manufactured without requiring high precision voltage control circuits or complex reference cell structures. The local charge portions are formed using standard semiconductor fabrication processes, making them inexpensive and easy to manufacture at high volumes, thereby improving production yield
Solution Approach 2:
The invention changes the operational parameters from requiring high precision bit line voltage control to using voltage levels that are naturally provided by the local charge portions. This parameter change eliminates the need for high precision voltage control during manufacturing, reducing manufacturing precision requirements and improving production yield
3Use of energy by moving object
If low voltage operation is implemented, then energy consumption is reduced, but reading current margin becomes insufficient
Solution Approach 1:
The invention stores complementary charges in advance in the local charge portions before reading operation. The first local charge portion stores positive charges and the second stores negative charges, creating a pre-prepared charge configuration that generates sufficient reading current even at low voltage operation, thereby preventing reading current margin insufficiency
Solution Approach 2:
The invention uses a composite charge storage structure with two local charge portions storing opposite charges. This composite approach, where positive and negative charges work together, generates a stronger and more stable reading current signal at low voltage compared to using a single charge storage element, thereby maintaining reading current margin while enabling low voltage operation
4Speed
If high speed data reading and writing is implemented, then operation speed is improved, but device complexity increases due to additional control circuits
Solution Approach 1:
The invention performs preliminary action by pre-storing complementary charges in the local charge portions during write operations. This pre-stored charge configuration enables rapid read operations without requiring complex real-time voltage control or reference cell comparisons, thereby achieving high speed data reading and writing while minimizing additional control circuit complexity
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 solution enables reliable, high-speed operation at low voltage and improves production yield by eliminating the need for a reference cell and allowing for efficient data storage and retrieval using paired local charge portions.
Implementation Method 1
multiple local charge portions capable of storing static charges in complementary states
Data Source
AI summary
A semiconductor memory device which is highly reliable, is operable at a low voltage and a high speed, and is produced at a high production yield is provided. A nonvolatile semiconductor memory device capable of reading and erasing data and holding the data even while no voltage is supplied comprises a plurality of memory cells each including a plurality of local charge portions each capable of storing a static charge corresponding to the data. Either two of the local charge portions store the charges in a complementary state.