Tunnel Insulation Layer Defect Cure via Dual-Side Annealing
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Solution Overview
Problem
Flash memory devices experience reliability issues due to dangling bonds in the tunnel insulation layer, which are not effectively cured by hydrogen annealing processes since hydrogen atoms cannot penetrate through certain layers like silicon nitride, leading to unchanged threshold voltages and reduced data retention.
Innovation Solution
A method of fabricating a non-volatile memory device involves forming a silicon nitride layer, an insulating interlayer, and providing an annealing gas to both the upper and lower faces of the substrate to cure defects in the tunnel insulation layer, allowing the annealing gas to penetrate and combine with dangling bonds, thereby improving the electrical characteristics of the tunnel insulation layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydrogen annealing process is applied to cure dangling bonds in tunnel insulation layer, then reliability of flash memory device is improved, but hydrogen atoms cannot penetrate through silicon nitride layer to reach tunnel insulation layer
Solution Approach 1:
The patent applies annealing gas to both the upper face and lower face of the substrate simultaneously. By introducing the annealing gas from the lower face dimension, the hydrogen atoms can penetrate through the substrate to reach the tunnel insulation layer without being blocked by the silicon nitride layer on the upper face, thus resolving the penetration barrier issue while maintaining reliability improvement
Solution Approach 2:
The substrate acts as an intermediary medium that allows hydrogen atoms to reach the tunnel insulation layer from the lower face. The annealing gas is introduced through the lower face of the substrate, using the substrate itself as a pathway or mediator to deliver hydrogen to the defective interface without requiring penetration through the blocking silicon nitride layer
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 approach enhances the reliability, endurance, and data retention of flash memory devices by effectively curing defects in the tunnel insulation layer, even when hydrogen cannot penetrate through the silicon nitride layer, resulting in improved electrical characteristics.
Implementation Method 1
providing an annealing gas toward an upper face of the substrate and a lower face of the substrate to cure defects of the tunnel insulation layer pattern
Implementation Method 2
an annealing process using hydrogen may be performed on the flash memory device
Data Source
AI summary
Example embodiments relate to methods of fabricating a non-volatile memory device. According to example embodiments, a method of fabricating a non-volatile memory device may include forming at least one gate structure on an upper face of a substrate. The at least one gate structure may include a tunnel insulation layer pattern, a charge storing layer pattern, a dielectric layer pattern and a control gate. According to example embodiments, a method of fabricating a non-volatile memory device may also include forming a silicon nitride layer on the upper face of the substrate to cover the at least one gate structure, forming an insulating interlayer on the silicon nitride layer on the upper face of the substrate, and providing an annealing gas toward the upper face of the substrate and a lower face of the substrate to cure defects of the tunnel insulation layer pattern.