DRAM Capacitor Contact Structure for Low Resistance and Gas Access
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Solution Overview
Problem
In semiconductor device manufacturing, particularly for DRAM, the scaling down of components leads to challenges such as increased resistance in capacitor contacts due to metal layers blocking gas flow paths, which hinders defect repair and affects electrical performance.
Innovation Solution
A semiconductor device design featuring a capacitor structure with a conductive layer and a dual-contact configuration, where the first contact portion penetrates through the insulating layer to connect with the conductive layer, and the second contact portion surrounds the lower portion, increasing the contact area and allowing hydrogen sintering to passivate silicon dangling bonds, thereby reducing threshold voltage and enhancing high-frequency operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal layer is used to cover the memory cell plate, then the resistance of the contact is reduced, but the gas flow paths are blocked preventing repair of process defects
Solution Approach 1:
The contact structure is segmented into multiple portions (first contact portion penetrating the insulating layer, second contact portion surrounding the lower portion) with different functions. The first contact portion provides electrical connection while the second contact portion allows gas flow for defect repair, thereby resolving the contradiction between low resistance and process accessibility.
Solution Approach 2:
Different portions of the contact structure have different properties: the first contact portion is designed for electrical conduction (penetrating through the insulating layer to reach the conductive layer), while the second contact portion is designed for gas access (surrounding the lower portion without fully enclosing it). This local differentiation allows simultaneous achievement of low resistance and defect repair capability.
2Productivity
If the component size is scaled down to increase integration density, then more components fit in the same area, but the metal layer blocks gas flow paths even more severely
Solution Approach 1:
By segmenting the contact into multiple functional portions, the invention enables gas flow paths to be maintained even as component size decreases. The second contact portion surrounding the lower portion provides dedicated gas access channels that remain effective at smaller scales, allowing defect repair while maintaining high integration density.
3Reliability
If the contact area is increased to reduce resistance, then the electrical performance improves, but the structure becomes more complex
Solution Approach 1:
The contact structure achieves multi-functionality: the first contact portion provides electrical connection, the second contact portion enables gas flow for defect repair, and together they provide increased contact area for low resistance. This universal design reduces the need for separate structures for each function, actually simplifying the overall device complexity while achieving multiple goals.
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 dual-contact configuration reduces capacitor contact resistance and facilitates defect repair, improving the electrical performance and manufacturing efficiency of semiconductor devices by allowing effective hydrogen passivation and defect repair during the hydrogen sintering process.
Implementation Method 1
allowing hydrogen to passivate silicon dangling bonds during a sintering process, thereby reducing resistance and improving electrical performance
Implementation Method 2
during a sintering process
Data Source
AI summary
A semiconductor device includes a first insulating layer over a substrate and a contact plug in the first insulating layer and in contact with the surface of the substrate. The semiconductor device further includes a capacitor structure above the contact plug and a second insulating layer on the first insulating layer and covering the capacitor structure. The capacitor structure includes a conductive layer over the first insulating layer. The semiconductor device further includes a capacitor contact over the capacitor structure. The capacitor contact includes a first contact portion and a second contact portion. The first contact portion penetrates through the second insulating layer and is in contact with the conductive layer of the capacitor structure. The second contact portion connects the outer surface of the first contact portion, and surrounds the lower portion of the first contact portion.