Oxide-Isolated Memory Decks to Prevent Inter-Deck Charge Trapping
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Solution Overview
Problem
As semiconductor industry seeks to increase memory density in non-volatile memory devices, reducing feature size of memory cells leads to increased risk of tunnel dielectric material failure and charge leakage, and conventional vertical memory arrays face challenges with charge trapping and reduced operating windows due to silicon nitride materials between decks.
Innovation Solution
Incorporating an oxide material, such as silicon dioxide, between decks of alternating conductive and insulative materials in microelectronic devices to prevent charge trapping and improve device performance by reducing electrical coupling between adjacent pillars, thereby enhancing read/write bias and operating window.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If feature size of memory cells is reduced to increase memory density, then memory density increases, but tunnel dielectric material reliability deteriorates
Solution Approach 1:
The patent applies different dielectric materials with different properties to different locations: silicon nitride is used in the charge storage node region where charge trapping is desired, while oxide material is used in the channel region where charge trapping would be harmful. This local differentiation allows the system to benefit from charge trapping for memory storage while avoiding its negative effects on channel performance, thus resolving the contradiction between increasing memory density and maintaining tunnel dielectric reliability.
2Quantity of substance
If silicon nitride material is used between decks to increase memory density, then memory density increases, but charge trapping increases causing reduced operating window
Solution Approach 1:
The patent selectively places silicon nitride material only in the charge storage node region rather than throughout the entire structure. The oxide material is used in the channel region between decks. This spatial differentiation allows charge trapping to occur only where needed for memory function, while preventing harmful charge trapping in the channel region, thus increasing memory density without the harmful side effects.
Solution Approach 2:
The oxide material acts as an intermediary layer between the channel materials of adjacent pillars, preventing direct electrical coupling and harmful charge trapping interactions. This intermediary material allows the system to achieve high density while maintaining proper electrical isolation, resolving the contradiction between density and charge trapping effects.
3Reliability
If electrical coupling between adjacent pillars is increased to improve device performance, then device performance improves, but charge trapping and gate-induced drain leakage increase
Solution Approach 1:
The patent creates different electrical coupling conditions in different regions: strong coupling is maintained in the charge storage node region for proper memory operation, while the oxide material in the channel region provides appropriate isolation to prevent harmful gate-induced drain leakage. This local differentiation resolves the contradiction between achieving necessary device performance and avoiding harmful leakage effects.
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
The oxide material effectively decouples channel materials between pillars, reducing charge trapping and improving memory cell performance by increasing the operating window and string current, while preventing interactions that lead to gate-induced drain leakage.
Implementation Method 1
an oxide material between the adjacent decks, the oxide material extending between an uppermost level of a first deck and a lowermost level of a second deck adjacent to the first deck
Data Source
AI summary
A microelectronic device includes decks comprising alternating levels of a conductive material and an insulative material, the decks comprising pillars including a channel material extending through the alternating levels of the conductive material and the insulative material, a conductive contact between adjacent decks and in electrical communication with the channel material of the adjacent decks, and an oxide material between the adjacent decks, the oxide material extending between an uppermost level of a first deck and a lowermost level of a second deck adjacent to the first deck. Related electronic systems and methods of forming the microelectronic device and electronic systems are also disclosed.