Embedded Capacitor Structure Using Single Silicon Nitride Deposition
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Solution Overview
Problem
Conventional embedded capacitor structures require multiple silicon nitride deposition processes, making the manufacturing process complex and costly.
Innovation Solution
A method to form an embedded capacitor structure using a single silicon nitride deposition process, involving a first dielectric layer with a trench, a capacitor structure with metal layers, and a cap layer, where contact windows are formed to expose metal surfaces, allowing for reduced silicon nitride deposition steps and simplified manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple silicon nitride deposition processes are used to form the embedded capacitor structure, then the structure can be completed with proper alignment and protection, but the manufacturing process becomes complex and costly
Solution Approach 1:
The patent combines multiple silicon nitride deposition processes into a single deposition step. The silicon nitride layer serves multiple functions simultaneously: as an etch stop layer, as a protective cap layer, and as part of the capacitor structure. This merging of functions reduces the number of deposition steps from multiple to one, simplifying the manufacturing process while maintaining structural integrity and alignment.
Solution Approach 2:
The single silicon nitride layer performs multiple functions that traditionally required separate layers and processes. It acts as an etch stop layer to define the trench depth, as a cap layer to protect the capacitor structure during subsequent processing, and as a structural component. This multi-functionality eliminates the need for separate deposition processes for each function.
2Reliability
If multiple silicon nitride deposition processes are used, then each layer can be optimized for its specific function, but the manufacturing cost increases
Solution Approach 1:
The patent merges the functions of multiple optimized layers into a single silicon nitride layer that performs all necessary functions simultaneously. By carefully designing the thickness and properties of this single layer, it achieves etch stop capability, protective cap functionality, and structural integrity without requiring multiple separate deposition processes, thereby reducing manufacturing cost.
Solution Approach 2:
The patent optimizes the thickness parameter of the single silicon nitride layer to achieve multiple functions. By adjusting the thickness to a specific range, the layer provides sufficient etch stop capability while maintaining adequate protection and structural support, eliminating the need for multiple layers with different thickness optimizations.
3Ease of manufacture
If a single silicon nitride deposition process is used, then manufacturing cost is reduced, but the alignment and structure formation must be achieved in one step
Solution Approach 1:
The patent performs preliminary actions by forming the silicon nitride layer with integrated etch stop and cap functions before subsequent processing steps. The layer is designed with pre-determined thickness and material properties that enable it to serve as both etch stop and protective cap during later trench formation and capacitor structure fabrication, ensuring proper alignment without requiring additional deposition steps.
Solution Approach 2:
The patent combines the etch stop layer and cap layer into a single silicon nitride layer deposited in one process step. This merging ensures that the layer is perfectly aligned with the trench structure from the beginning, as it is formed before trench etching and serves as the reference for subsequent processing steps, eliminating alignment issues that would arise from multiple separate deposition steps.
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 reduces manufacturing costs, simplifies the process, and enhances capacitance density by minimizing silicon nitride deposition steps while ensuring accurate alignment and complete structure formation.
Implementation Method 1
a cap layer is formed on the top surface and the inner surface of the trench and on the capacitor structure
Data Source
AI summary
A method for forming an embedded capacitor structure is provided. Firstly, a first dielectric layer having a trench therein on a substrate is provided. A capacitor structure is formed on the bottom surface of the trench. The capacitor structure includes a first metal layer, a capacitance-insulating layer and a second metal layer and the portion surface of the first metal layer on the bottom surface of the trench is exposed. A cap layer is formed on the top surface and the inner surface of the trench and on the capacitor structure. A second dielectric layer is formed on the cap layer. The portion of second dielectric layer and the portion of the cap layer are removed to form a plurality of contact windows therein, and the portion surface of the first metal layer and the portion surface of the second metal layer are exposed by the plurality of contact windows.