Semiconductor Memory Charge Storage Film Metal Oxide Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The semiconductor memory device faces challenges with interference and charge transfer between neighboring memory cells due to the thin film thickness of charge storage films, which affects memory density and charge retention, and using silicon nitride as a charge storage film results in decreased charge accumulation when film thickness is reduced.
Innovation Solution
The semiconductor memory device employs a stacked configuration with a first insulating layer, a conductive layer, and a second insulating layer alternately stacked, featuring a tunnel insulating film, a block insulating film, and a charge storage film containing metal oxide or metal oxynitride, with specific portions connected to prevent interference and enhance charge retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the film thickness of charge storage films is reduced to increase memory density, then memory integration is improved, but interference and charge transfer between neighboring memory cells increases
Solution Approach 1:
A block insulating film is introduced as an intermediary layer between adjacent charge storage films. This block insulating film acts as a barrier that prevents charge transfer and interference between neighboring memory cells, while allowing the charge storage films to maintain reduced thickness for high density integration.
Solution Approach 2:
The charge storage function is segmented into multiple components: charge storage films for charge accumulation and block insulating films for isolation. This segmentation allows each component to be optimized independently - charge storage films can be thin for high density while block insulating films provide necessary isolation to prevent interference.
2Quantity of substance
If silicon nitride is used as charge storage film material, then charge storage capability is improved, but charge accumulation decreases when film thickness is reduced
Solution Approach 1:
The patent employs composite material structures combining charge storage films (such as silicon nitride) with block insulating films. This composite approach allows the charge storage film to maintain optimal thickness for charge accumulation while the block insulating film compensates for the reduced charge storage capacity by preventing charge leakage to adjacent cells.
Solution Approach 2:
The patent changes the material parameters and structural configuration by introducing block insulating films with different dielectric properties. This parameter change allows the system to maintain effective charge retention even when the charge storage film thickness is reduced, as the block insulating film provides an additional barrier against charge transfer.
Data Source
AI summary
A semiconductor memory device of an embodiment includes a stacked body including a first insulating layer, a first conductive layer and a second insulating layer; a semiconductor film extending in a first direction; a tunnel insulating film provided between the stacked body and the semiconductor film, the tunnel insulating film extending in the first direction; a first block insulating film provided between the first conductive layer and the tunnel insulating film; and a first charge storage film containing a metal oxide or a metal oxynitride and including: a first portion provided between the tunnel insulating film and the first block insulating film, a second portion provided between the tunnel insulating film and the first insulating layer, the second portion being connected to the first portion and a third portion provided between the tunnel insulating film and the second insulating layer, the third portion being connected to the first portion.