Oxide Cluster Semiconductor Memory Charge Accumulation
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Solution Overview
Problem
In semiconductor memory devices with silicon oxide films, impurities like Al, Au, and Ti atoms diffuse, causing charge accumulation inefficiencies due to charge migration in the silicon oxide film.
Innovation Solution
The use of zirconium oxide or hafnium oxide clusters, covered with SiO2 and Al2O3, as charge accumulating films, which prevent charge leakage and stabilize charge accumulation by forming high dielectric constant materials with large band offsets, and incorporating elements like Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Ta, W, Re, Os, Ir, Pt, and Hg to enhance charge storage capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If impurities such as Al atoms, Au atoms and Ti atoms are included in the silicon oxide film to create trap sites for charge accumulation, then charge accumulation capability is improved, but charge leakage occurs due to diffusion of these impurities in the silicon oxide
Solution Approach 1:
The patent uses a composite structure consisting of a silicon oxide film containing oxide clusters (such as SiOx clusters where x>2) embedded within a charge accumulating film. This composite material approach allows the oxide clusters to provide trap sites for charge accumulation while the surrounding silicon oxide matrix prevents impurity diffusion, thus resolving the contradiction between charge accumulation capability and charge leakage.
Solution Approach 2:
The patent introduces oxide clusters at specific locations within the charge accumulating film to create localized trap sites for charge accumulation. These oxide clusters are distributed throughout the film but concentrated in regions where charge trapping is needed, providing local charge accumulation capability without requiring diffuse impurities throughout the entire film, thereby preventing charge leakage.
2Quantity of substance
If conventional silicon oxide film with impurities is used for charge accumulation, then charge storage is achieved, but threshold voltage variability increases due to charge diffusion
Solution Approach 1:
The patent employs a composite charge accumulating film structure with oxide clusters embedded in a silicon oxide matrix. This composite structure provides uniform charge distribution and stable trap sites, reducing threshold voltage variability while maintaining charge storage capability. The oxide clusters act as discrete, well-defined trapping centers rather than diffuse impurity sites.
3Quantity of substance
If Al atoms, Au atoms and Ti atoms are used as impurities in silicon oxide film, then trap sites are introduced for charge accumulation, but writing and erasing speeds are reduced due to charge diffusion
Solution Approach 1:
The patent uses oxide clusters as localized charge trapping centers within the charge accumulating film. These clusters provide discrete, well-defined trap sites that enable faster charge capture and release compared to diffuse impurity sites. The localized nature of oxide clusters allows for quicker writing and erasing operations while maintaining effective charge accumulation.
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 effectively prevents charge leakage, allows stable charge accumulation, and enables efficient operation with reduced threshold voltage variability, facilitating faster writing and erasing speeds while maintaining low power consumption.
Implementation Method 1
The use of zirconium oxide or hafnium oxide clusters, covered with SiO2 and Al2O3, as charge accumulating films, which prevent charge leakage and stabilize charge accumulation by forming high dielectric constant materials with large band offsets
Data Source
AI summary
According to one embodiment, in a semiconductor memory device, a source region and a drain region are disposed away from each other in the semiconductor layer. A tunnel insulating film is formed between the source region and the drain region on the semiconductor layer. A charge accumulating film includes an oxide cluster and is formed on the tunnel insulating film. A block insulating film is formed on the charge accumulating film. A gate electrode is formed on the block insulating film. The oxide cluster includes either Zr or Hf, and further contains at least one element selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Ta, W, Re, Os, Ir, Pt, Au and Hg.