Antifuse Circuit for Memory Defect Address Storage and Correction
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Solution Overview
Problem
The challenge in the semiconductor industry is the high cost and time required to replace defective memory chips in memory modules due to defects occurring after packaging, which are not easily corrected using existing methods like laser beam irradiation, especially since these defects often result in single-bit errors rather than multi-bit errors.
Innovation Solution
The implementation of an antifuse circuit unit within memory devices that stores and updates defective cell addresses and characteristic codes, allowing for external output and correction of these defects through a memory controller or buffer, enabling alternative access and data handling without re-operating the memory module.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If re-operation is performed to remove defective memory chip and re-mount another memory chip, then defective memory chip can be replaced, but manufacturing cost increases and production time is extended
Solution Approach 1:
The patent applies preliminary action by detecting and recording defective cell addresses during the manufacturing process using an antifuse circuit. The defective addresses are stored in the antifuse memory structure before the product leaves the factory, enabling automatic correction during operation without requiring re-operation. This preliminary detection and recording mechanism prevents the need for costly and time-consuming re-mounting processes.
Solution Approach 2:
The patent uses copying by creating a mapping between defective cell addresses and their correct counterparts. The antifuse circuit stores copies of the defective address information, which is then used to redirect access to defective cells to their correct locations during memory operations. This copying mechanism allows the system to work around defects without physical replacement of memory chips.
2Reliability
If re-operation is performed to remove defective memory chip and re-mount another memory chip, then defective memory chip can be replaced, but manufacturing cost increases
Solution Approach 1:
The patent applies preliminary action by detecting and recording defective cell addresses during the manufacturing process using an antifuse circuit. The defective addresses are stored in the antifuse memory structure before the product leaves the factory, enabling automatic correction during operation without requiring re-operation. This preliminary detection and recording mechanism prevents the need for costly and time-consuming re-mounting processes.
Solution Approach 2:
The patent implements self-service by enabling the memory device to automatically correct its own defects using the antifuse-stored address information. The system self-diagnoses defective cells and self-corrects by redirecting access through the stored mapping information, eliminating the need for external re-operation and reducing manufacturing costs associated with manual intervention.
3Reliability
If laser beam irradiation is used to correct defects, then multi-bit errors can be corrected, but single-bit errors occurring after packaging cannot be easily corrected
Solution Approach 1:
The patent uses copying by creating a mapping between defective cell addresses and their correct counterparts. The antifuse circuit stores copies of the defective address information, which is then used to redirect access to defective cells to their correct locations during memory operations. This copying mechanism allows the system to work around defects without physical replacement of memory chips.
Solution Approach 2:
The patent applies dynamics by implementing a flexible address mapping mechanism that can adapt to different types of defects occurring at different stages. The antifuse circuit dynamically stores and updates defective address information, allowing the system to handle both single-bit and multi-bit errors regardless of when they occur during the product lifecycle, enhancing the versatility of the correction 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
This solution reduces manufacturing costs and time by allowing for the identification and correction of defective memory cells within the memory module without re-mounting, effectively rescuing defective chips and maintaining module functionality.
Implementation Method 1
an antifuse circuit unit comprising at least one antifuse that stores a defective cell address of the memory cell array in the at least one antifuse
Data Source
AI summary
A memory device capable of rescuing defective characteristics that occur after packaging includes a memory cell array including a plurality of memory cells and an antifuse circuit unit including at least one antifuse. The antifuse circuit unit stores a defective cell address of the memory cell array in the at least one antifuse and reads the defective cell address to an external source. The antifuse circuit unit stores a defective characteristic code in the at least one antifuse, wherein the defective characteristic code is related to at least one of a timing parameter spec., a refresh spec., an input/output (I/O) trigger voltage spec., and a data training spec. of the memory device, and outputs the defective characteristic code to an external source.