Non-Volatile Memory Initial Data Setting via Asymmetric Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-volatile memory devices with hot carrier injection technology face challenges in setting initial data values, leading to indefinite data states during shipment inspection, which complicates defect detection and requires additional configurations to set '0' as the initial value.
Innovation Solution
The non-volatile memory device configuration includes a constant current source, NMOS transistors, and resistor elements, allowing for the setting of an initial data value by varying resistance values based on the programmability of memory elements, eliminating the need for paired characteristics and simplifying the initial data setting process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hot carrier injection is used to change transistor characteristics for data storage, then non-volatile memory functionality is achieved, but the initial data state becomes indefinite making defect inspection impossible
Solution Approach 1:
The patent applies preliminary action by configuring the transistor circuit such that a higher current passes through the second transistor in the initial state, thereby pre-establishing a known initial data value of '0' before any hot carrier injection occurs. This preliminary configuration enables defect inspection to be performed during shipment while maintaining the non-volatile memory functionality achieved through hot carrier injection.
2Ease of operation
If paired transistor characteristics are used in initial state, then memory operation is enabled, but additional configurations are required to set initial data value to '0'
Solution Approach 1:
The patent applies asymmetry by creating an asymmetric current distribution in the paired transistor circuit, where the second transistor is configured to carry a higher current than the first transistor in the initial state. This asymmetric configuration naturally establishes the initial data value as '0' without requiring additional complex configuration circuits, thereby simplifying the device while maintaining ease of operation.
3Reliability
If higher current passes through second transistor in initial state, then initial data value is fixed to '0', but the configuration becomes more complex
Solution Approach 1:
The patent applies local quality by making a targeted modification only to the second transistor in the paired circuit, configuring it to carry higher current in the initial state. This localized change to a specific transistor's current characteristics is sufficient to establish the initial data value as '0' without requiring complex reconfiguration of the entire memory device, thereby achieving reliable initial data fixation with minimal added complexity.
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 configuration enables the setting of an initial data value without relying on paired characteristics, reducing errors and simplifying the data initialization process, while maintaining the ability to store '0' and '1' values effectively.
Implementation Method 1
Non-volatile memories that exploit hot carrier injection into transistors are known
Data Source
AI summary
A non-volatile memory device includes: a first current mirror; a second current mirror; a first resistor portion connected to a first MOS transistor included in the first current mirror; a second resistor portion connected to a second MOS transistor included in the second current mirror; and a sensing portion configured to sense the magnitude relationship between a first current through the first MOS transistor and a second current through the second MOS transistor. The first resistor portion includes a first memory element, which is programmable, and according to whether the first memory element is programmed, the resistance value of the first resistor portion changes.