Dielectric Bonding Structure for Stable DRAM Bit Lines
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Solution Overview
Problem
DRAM manufacturers face challenges in shrinking memory cell area due to increasing word line spacing, leading to instability in bit lines and low yield.
Innovation Solution
A semiconductor device with a bonding structure comprising a dielectric material is used, where the bit line is disposed on the bonding structure and the channel layer is disposed on the bit line, with the word line surrounding the channel layer. The bonding structure is formed using a fusion bonding technique between two dielectric layers, eliminating voids at the interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal to metal bonding is used to bond two substrates, then the bonding strength is improved, but voids are formed at the interface between metal layers causing bit line instability
Solution Approach 1:
A dielectric layer is introduced as an intermediary material between the metal layers to eliminate void formation. The dielectric layer bonds to both metal surfaces, preventing the interface voids that occur in direct metal-to-metal bonding while maintaining structural integrity and bit line stability.
Solution Approach 2:
The bonding interface material is changed from metal to dielectric, fundamentally altering the bonding parameters. This parameter change eliminates the void formation mechanism inherent in metal-to-metal bonding while achieving sufficient bonding strength through dielectric properties.
2Area of stationary object
If word line spacing is reduced to shrink memory cell area, then the memory cell area is reduced, but bit line instability increases
Solution Approach 1:
The dielectric layer serves as a stabilizing intermediary that prevents void formation at the bonding interface, thereby maintaining bit line stability even when word line spacing is reduced to achieve smaller memory cell areas.
3Reliability
If fusion bonding technique is used to bond dielectric layers, then voids are eliminated at the interface, but the manufacturing process complexity increases
Solution Approach 1:
The dielectric layer acts as an intermediary that enables void-free bonding through fusion bonding technique. While the process is more complex than direct metal bonding, the dielectric intermediary prevents void formation and ensures high yield.
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
The approach enhances the yield of semiconductor devices by eliminating voids in the bit lines, thereby improving the stability and performance of the semiconductor device.
Implementation Method 1
a fusion bonding technique is utilized. Fusion bonding technique involves bonding two dielectric layers formed on two individual substrates
Data Source
AI summary
A semiconductor device and method for manufacturing the same are provided. The semiconductor device includes a substrate, a bonding structure, a bit line, and a word line. The bonding structure is disposed on the substrate. The bit line is disposed on the bonding structure. The channel layer is disposed on the bit line. The word line surrounds the channel layer. The bonding structure includes a dielectric material.