Semiconductor Fuse Circuit for Defective Cell Replacement
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Solution Overview
Problem
Semiconductor devices, such as DRAM, face challenges in efficiently replacing defective memory cells with redundant ones after packaging, as existing methods lack effective mechanisms for storing and managing defective address information post-packaging.
Innovation Solution
The semiconductor device employs a configuration with multiple input nodes, decoders, and fuse circuits programmed based on input signals to decode and store defective address information, allowing for the selection of redundant memory cells to replace defective ones, using anti-fuse elements for programming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If anti-fuse elements are used to store defective address information after packaging, then the ability to replace defective memory cells is improved, but the programming time increases due to the large number of anti-fuse elements required
Solution Approach 1:
The patent divides the address information into multiple segments and stores them in different fuse circuits. Each fuse circuit handles a portion of the address bits, allowing parallel programming operations. This segmentation reduces the total programming time while maintaining the capability to replace defective memory cells after packaging.
Solution Approach 2:
The patent introduces a new dimension of organization by using multiple fuse circuits with different input terminals instead of using a single large array of anti-fuse elements. This dimensional reorganization allows for more efficient address storage and reduces programming time by enabling concurrent operations across multiple fuse circuits.
2Adaptability or versatility
If multiple anti-fuse elements are used to store all possible defective address information, then the coverage of defective cell replacement is improved, but the device complexity increases
Solution Approach 1:
The patent makes each fuse circuit multi-functional by enabling it to handle multiple address bits through different input terminals. Each fuse circuit can be programmed to respond to different address patterns, providing universal coverage for defective cell replacement without requiring a separate anti-fuse element for each possible defective address.
Solution Approach 2:
The patent uses multiple fuse circuits that are essentially copies of the same basic circuit structure, each capable of storing address information. This copying approach provides comprehensive defective address coverage while maintaining a manageable device complexity through standardized, reusable circuit modules.
3Reliability
If a large number of fuse circuits are used to ensure complete address coverage, then the reliability of defective cell replacement is improved, but the manufacturing cost increases
Solution Approach 1:
The patent applies local quality by configuring specific fuse circuits to handle specific address bits or patterns based on the actual defective cells found during testing. Instead of uniformly distributing all possible address coverage across all fuse circuits, each fuse circuit is optimized for its specific function, reducing the total number of fuse circuits needed while maintaining high replacement reliability.
Data Source
AI summary
Disclosed here is a semiconductor device that comprises plurality of input nodes configured to be supplied with input signals, a decoder coupled to the input nodes, the decoder configured to decode the input signals and output decoded sepals, and a plurality of fuse circuits provided correspondingly with the decoded signals and configured to be programmed responsive to the decoded signals, respectively