Air Gap Fabrication Adjacent Bit Line Structures
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Solution Overview
Problem
Current DRAM units with buried gate structures face limitations in fabrication capability, affecting their performance and reliability as electronic products trend towards miniaturization and higher integration.
Innovation Solution
A method for fabricating semiconductor devices involves forming air gaps adjacent to bit line structures by creating a substrate with defined cell and peripheral regions, forming bit line and gate structures, and using photo-etching processes to form storage contacts and cap layers, ultimately resulting in a U-shaped first cap layer and air gaps adjacent to the bit line structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional fabrication processes are used for DRAM units with buried gate structures, then manufacturing simplicity is maintained, but fabrication capability and device performance are limited
Solution Approach 1:
The fabrication process is divided into multiple sequential photo-etching stages, each creating specific features (storage contacts, air gaps, cap layers) separately. This segmentation allows precise control over each structure's formation, improving fabrication capability and device performance while managing complexity through systematic process breakdown
Solution Approach 2:
The method performs preliminary actions by forming the first cap layer before creating air gaps, and forming storage contacts before finalizing the bit line structure. These preliminary structures serve as masks and templates for subsequent processing steps, enabling precise feature formation while improving overall fabrication capability
2Productivity
If miniaturization is pursued to achieve higher integration, then device density increases, but fabrication precision requirements become more stringent
Solution Approach 1:
The fabrication method applies different processing conditions and materials to specific local regions: the first cap layer is selectively formed only in certain areas, air gaps are created only adjacent to bit line structures, and storage contacts are positioned at specific locations. This local quality approach enables precise control over feature formation, meeting stringent manufacturing precision requirements while achieving high device integration density
Solution Approach 2:
The method introduces vertical dimensionality by forming multi-layer cap structures (first cap layer and second cap layer) and creating air gaps at different depths. This dimensional approach allows complex three-dimensional feature formation with precise control, enabling miniaturization and higher integration while maintaining fabrication precision
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 performance and reliability of DRAM devices by improving the fabrication process, allowing for higher integration and density in semiconductor devices.
Implementation Method 1
performing a first photo-etching process to remove part of the conductive layer for forming storage contacts adjacent two sides of the bit line structure and contact plugs adjacent to two sides of the gate structure
Data Source
AI summary
A method for fabricating semiconductor device includes the steps of: providing a substrate having a cell region and a peripheral region; forming a bit line structure on the cell region and a gate structure on the peripheral region; forming an interlayer dielectric (ILD) layer around the bit line structure and the gate structure; forming a conductive layer on the bit line structure; performing a first photo-etching process to remove part of the conductive layer for forming storage contacts adjacent two sides of the bit line structure and contact plugs adjacent to two sides of the gate structure; forming a first cap layer on the cell region and the peripheral region to cover the bit line structure and the gate structure; and performing a second photo-etching process to remove part of the first cap layer on the cell region.