Semiconductor Device Self-Repair Boot-Up Control
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Solution Overview
Problem
High-density integration in semiconductor memory devices leads to increased process defects and yield loss due to the lack of effective schemes for detecting and repairing defects in the ARE circuit, particularly in the non-volatile memory and redundancy cells.
Innovation Solution
A semiconductor device with a non-volatile memory comprising normal, self-repair, and redundancy regions, equipped with control blocks for detecting defective cells during boot-up, programming defective addresses into the self-repair region, and reading data from the redundancy region when necessary, thereby enabling self-repair and improving yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-density integration is implemented to increase memory capacity, then cell density and storage capacity are improved, but process defects and yield loss increase due to the lack of effective defect detection and repair schemes
Solution Approach 1:
The non-volatile memory is segmented into three distinct regions: normal region, self-repair region, and redundancy region. This segmentation allows defective cells to be isolated and replaced without affecting the entire memory array, thereby maintaining high cell density while improving yield through targeted defect management.
Solution Approach 2:
The self-repair region is pre-programmed with defective address information before the memory device is put into service. During the boot-up operation, the system automatically detects defective cells and programs their addresses into the self-repair region, enabling proactive defect management before the memory is fully utilized.
Solution Approach 3:
The memory device performs automatic self-diagnosis and self-repair during the boot-up operation. The first boot-up control block detects defective cells in the normal region, and the self-program control block automatically programs the defective addresses into the self-repair region without requiring external intervention, thereby improving yield through autonomous defect management.
2Reliability
If the number of redundancy cells is increased to compensate for process defects, then yield is improved, but the density integration of the ARE circuit increases leading to more process defects
Solution Approach 1:
Instead of uniformly increasing redundancy across the entire ARE circuit, the invention applies redundancy locally only where defects are detected. The self-repair region contains spare fuse cells that are activated only when specific defective addresses are identified, allowing the ARE circuit to maintain high density while providing targeted yield improvement.
Solution Approach 2:
The system dynamically changes the operational parameters of the ARE circuit by switching between normal region, self-repair region, and redundancy region based on detected defects. This allows the circuit to adapt its density and redundancy levels according to actual defect locations, optimizing both yield and density.
3Device complexity
If conventional ARE circuit design is used without defect detection capability, then device complexity is reduced, but defect location identification becomes impossible leading to yield loss
Solution Approach 1:
The defect detection and repair functionality is merged into the existing ARE circuit structure. The first boot-up control block, self-program control block, and comparison block are integrated with the normal memory operations, allowing defect detection and repair without requiring a completely separate complex system, thereby maintaining relatively simple device architecture while improving yield.
Solution Approach 2:
The non-volatile memory structure serves multiple functions: it acts as both the primary ARE circuit for storing fuse data and as a defect detection and repair system. The same memory cells and control blocks are used for both normal operation and self-diagnosis, eliminating the need for separate dedicated defect management hardware and maintaining device simplicity.
Data Source
AI summary
A semiconductor device includes: a non-volatile memory including a normal region, a self-repair region and a redundancy region, each having a plurality of cells; a first boot-up control block suitable for controlling a first boot-up operation to detect defective cells of the normal region and store a defective address in a first latch unit; a self-program control block suitable for controlling a self-program operation to program the defective address stored in the first latch unit into the self-repair region; and a second boot-up control block suitable for controlling a second boot-up operation to read out data of the normal region based on an input address while reading out data of the redundancy region instead of the data of the normal region when data of the self-repair region coincides with the input address.