Semiconductor Refresh Control Circuit for Repair Efficiency

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Solution Overview

Problem

Conventional semiconductor apparatuses face inefficiencies in repair operations due to the likelihood of refresh errors when adjacent word lines share a sense amplifier, leading to degraded repair efficiency and potential data corruption.

Innovation Solution

A refresh control circuit and method that includes a repair address processing unit, a refresh counter, and a refresh control unit to manage additional refresh modes, enabling simultaneous activation of word lines in predetermined units and converting the semiconductor apparatus to an initialization state for efficient repair and refresh operations, thereby minimizing errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If two adjacent word lines are simultaneously activated to increase refresh speed, then refresh operation speed is improved, but refresh errors occur due to sense amplifier sharing

Engineering Contradiction:

Improverefresh operation speedVSAvoidrefresh operation reliability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The refresh operation is segmented into two distinct phases: a first refresh operation for normal word lines and a second refresh operation for redundant word lines. This segmentation prevents simultaneous activation of adjacent word lines that share sense amplifiers, thereby eliminating refresh errors while maintaining improved refresh speed through the additional refresh mode.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The refresh control circuit performs preliminary actions by first completing the refresh operation for normal word lines before initiating the refresh operation for redundant word lines. This sequential preliminary action ensures that sense amplifiers are properly deactivated and reactivated between operations, preventing data corruption while achieving faster overall refresh through the additional refresh mode.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If repair range is limited to avoid refresh errors, then refresh reliability is improved, but repair efficiency is degraded

Engineering Contradiction:

Improverefresh operation reliabilityVSAvoidrepair efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system dynamically switches between normal refresh mode and additional refresh mode based on the presence of failed memory cells. In additional refresh mode, the refresh control circuit activates redundant word lines for repairing failed memory cells while maintaining proper sequencing to avoid refresh errors. This dynamic adaptation allows full utilization of repair capabilities without sacrificing reliability.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The refresh control circuit changes operational parameters by introducing an additional refresh mode that modifies the refresh sequence and timing. This parameter change enables the system to refresh both normal and redundant word lines effectively, maximizing repair efficiency while maintaining reliability through controlled sequential operation rather than simultaneous activation.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If redundant word lines are activated for repairing failed memory cells, then repair capability is improved, but refresh errors occur when adjacent word lines share sense amplifiers

Engineering Contradiction:

Improverepair capabilityVSAvoidrefresh operation reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The refresh operation is segmented into distinct phases: first refreshing normal word lines, then refreshing redundant word lines. This segmentation allows the system to activate redundant word lines for repair purposes without simultaneously activating adjacent normal word lines that share sense amplifiers, thereby maintaining both repair capability and refresh reliability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system performs preliminary refresh operations on normal word lines before activating redundant word lines for repair. This preliminary action ensures that sense amplifiers are properly managed between operations, preventing refresh errors while enabling full utilization of redundant word lines for repairing failed memory cells.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9171604B2Refresh control circuit of semiconductor apparatus and refresh method using the same

Publication Date: 2015.10.27 SK HYNIX INC

AI summary

A refresh control circuit of a semiconductor apparatus includes a repair address processing unit configured to compare refresh addresses and repair information, activate a redundant enable signal, and convert the semiconductor apparatus into the same operation state as an initialization state of the repair information in response to activation of a repair initialization signal; a refresh counter configured to count the refresh addresses extended to a signal bit in response to activation of a redundant count enable signal; and a refresh control unit configured to activate the repair initialization signal and the redundant count enable signal when an additional refresh mode is set in response to a refresh command.