TiN Floating-Gate Super Flash With Oxygen Diffusion Barriers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing super flash manufacturing process faces issues with the discontinuity of the titanium nitride floating gate due to high-temperature reactions with oxygen, affecting the electrical erasure performance of the device.
Innovation Solution
The introduction of nitrogen oxide layers between the TiN layer and the oxide layers on both sides, forming an O—N—TiN—N—O structure, prevents excessive oxygen diffusion and maintains the TiN layer's continuity, allowing stored charges to be effectively erased and captured.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high-temperature oxidation (HTO) is used to form oxide layers, then the oxide layer quality is improved, but the titanium nitride floating gate becomes discontinuous due to oxygen reaction
Solution Approach 1:
A nitrogen oxide layer is introduced as an intermediary barrier between the oxide layer and the titanium nitride floating gate. This nitrogen oxide layer prevents excessive oxygen diffusion to the TiN layer while allowing the oxide layer to be formed by HTO, thus resolving the contradiction between oxide layer quality and TiN continuity
Solution Approach 2:
The nitrogen oxide layer creates a protective environment around the titanium nitride floating gate, preventing oxygen from reaching and reacting with the TiN layer during high-temperature processing, thereby maintaining TiN continuity while still allowing high-quality oxide formation
2Reliability
If the floating gate structure is changed to improve erasing efficiency, then the erasure performance is improved, but the manufacturing complexity increases
Solution Approach 1:
The insulating layer is segmented into multiple sub-layers: a first oxide layer, a nitrogen oxide layer, and a second oxide layer. This segmentation allows each layer to perform its specific function independently, improving erasure performance while keeping the manufacturing process manageable through standardized layer formation techniques
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 solution ensures continuous TiN structures for improved erasure performance and enhanced charge capture capabilities, while maintaining simplicity in the manufacturing process without adverse impacts on other device structures.
Implementation Method 1
The nitrogen oxide layers respectively prevent excessive O on both sides from diffusing to the TiN layer
Implementation Method 2
a reaction of oxygen with titanium nitride occurs at a high temperature, resulting in the discontinuity of the titanium nitride
Data Source
AI summary
The application discloses a super flash including: a first gate trench formed at the top of a source region, wherein a floating gate and a control gate are formed in the first gate trench. A second nitrogen oxide layer and a first oxide layer are formed between a first side surface of the floating gate and side and bottom surfaces of the first gate trench. A third nitrogen oxide layer and a fourth oxide layer are formed between a second side surface of the floating gate and a side surface of the control gate. The floating gate is a TiN layer; and the top of the floating gate is higher than a top surface of the control gate. The second nitrogen oxide layer and the third nitrogen oxide layer prevent the diffusion of oxygen into the floating gate. The present application also discloses a method for manufacturing a super flash.