Non-volatile Memory Word Redundancy for Yield Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional non-volatile memory requires multiple redundant columns or rows to achieve sufficient yield, leading to inefficient resource utilization and increased complexity due to the need for extensive redundancy management, which hinders miniaturization and operation speed.
Innovation Solution
A non-volatile memory system utilizing word redundancy, where one redundant data storage unit substitutes for a defective data storage unit within the same column, with the redundant address storage unit recording only the row address, eliminating the need for column address recording and optimizing resource usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple redundant columns or rows are used to achieve sufficient yield, then reliability is improved, but device complexity increases and resource utilization deteriorates
Solution Approach 1:
The patent segments the address management function into two parts: the main memory array handles data storage, while a separate redundant address storage unit handles only the row address information for defective cell substitution. This segmentation reduces the complexity of redundancy management by dividing the address management task from the data storage task.
Solution Approach 2:
The patent extracts only the necessary row address information from the full address, storing only this essential part in the redundant address storage unit while discarding the column address component. This extraction principle reduces the amount of information that needs to be managed during redundancy operations.
2Reliability
If one storage column is replaced by an entire redundant column due to one defective memory cell, then reliability is improved, but resource utilization deteriorates
Solution Approach 1:
The patent applies local quality by allowing different parts of the memory array to have different functionalities. Specifically, most storage columns maintain their normal data storage function, while only the specific column containing a defective cell is substituted by a redundant column. This localized substitution approach maximizes resource utilization by preserving functional columns.
Solution Approach 2:
The patent changes the substitution parameter from column-level replacement to cell-level replacement. Instead of replacing an entire column when one cell is defective, the system identifies and substitutes only the specific defective cell using a redundant cell from a redundant row, thereby maintaining optimal resource utilization while ensuring reliability.
3Reliability
If external controller is used to manage redundancy, then reliability is improved, but operation speed deteriorates and miniaturization is hindered
Solution Approach 1:
The patent implements self-service by integrating the redundancy management functionality directly into the memory array structure. The redundant address storage unit and redundant data storage units work autonomously with the main memory array, enabling the memory system to manage its own defects without requiring an external controller. This self-managing capability improves operation speed and enables miniaturization.
Data Source
AI summary
A non-volatile memory includes a plurality of data storage units arranged in an array, a plurality of redundant data storage units arranged in at least one row and a plurality of redundant address storage units arranged in at least one row. A storage size of each of the data storage units is word. Each of the data storage units is addressable by a row address and a column address. One of the redundant data storage units in a first column is configured to substitute for one of the data storage units in a second column. One of the redundant address storage units in a third column is configured to record the row address representative of the substituted one of the data storage units.