Word Line Control Circuit for Non-Adjacent Activation
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Solution Overview
Problem
Existing methods for identifying low storage capacitance in memory chips are inadequate, as they rely on activating adjacent word lines, which can be affected by contact area disconnections or high impedance, making it difficult to accurately determine defective capacitors.
Innovation Solution
A word line control method that involves acquiring a row address input signal, performing logical and decoding operations to generate a row address control signal, and simultaneously activating at least two non-adjacent word lines, ensuring that tests are not affected by contact area issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If two adjacent word lines are activated simultaneously to test storage capacitors, then the test can identify low capacitance defects, but the test is affected by contact area disconnections or high impedance making accurate defect identification difficult
Solution Approach 1:
The patent segments the word line activation into two distinct groups: odd-numbered word lines and even-numbered word lines. By selectively activating only odd or only even word lines based on the least significant bit of the row address, the patent ensures that capacitors sharing the same contact area are not simultaneously activated, thereby eliminating the interference from contact area disconnections or high impedance.
2Difficulty of detecting and measuring
If two adjacent word lines are activated to test capacitors, then low capacitance defects can be detected, but contact area malfunctions prevent accurate determination of defective capacitors
Solution Approach 1:
The patent divides the word line activation pattern into two separate segments (odd and even word lines) and uses the least significant bit of the row address to select which segment to activate. This segmentation ensures that capacitors sharing contact areas are never simultaneously activated, allowing accurate measurement of individual capacitor defects without interference from contact area malfunctions.
3Reliability
If adjacent word lines are activated for testing, then capacitor defects can be identified, but contact area issues create false test results
Solution Approach 1:
The patent segments the word line activation into odd and even groups, preventing simultaneous activation of capacitors that share contact areas. This eliminates the harmful effect of contact area disconnections or high impedance on test results.
Solution Approach 2:
Instead of activating adjacent word lines as traditionally done, the patent inverts the approach by activating only non-adjacent word lines (either all odd or all even numbered lines), thereby avoiding the contact area interference problem entirely.
Data Source
AI summary
A word line control method, a word line control circuit device, and a semiconductor memory are provided. The method includes: acquiring a row address input signal; acquiring a test mode signal; performing logical and decoding operations on the row address input signal and the test mode signal to generate a row address control signal, wherein the row address control signal includes at least two valid activation signals; and simultaneously activating at least two non-adjacent word lines based on the at least two valid activation signals. The row address control signal obtained allows simultaneous activation of at least two non-adjacent word lines. Since none of any two non-adjacent word lines share a common contact area, a test will not be affected by the disconnection of a contact area or the presence of high impedance, thus improving test accuracy.