Semiconductor Capacitor Intermediate Dielectric Layer Warping
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Solution Overview
Problem
Increasing the thickness of the dielectric layer in semiconductor devices to enhance voltage-sustaining capability leads to substrate warping and complicates the fabrication process, as it affects the inter-metal dielectric layer and original process flow.
Innovation Solution
Incorporating an intermediate dielectric layer with higher relative permittivity between the lower and upper electrodes of the capacitor, which increases breakdown voltage without increasing the distance between the electrodes, thereby simplifying the fabrication process and reducing substrate warping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the thickness of the dielectric layer is increased to enhance voltage-sustaining capability, then the breakdown voltage is improved, but the substrate warps and the fabrication process becomes complicated
Solution Approach 1:
The dielectric layer is segmented into multiple sub-dielectric layers with different thicknesses and material compositions. The first sub-dielectric layer has greater thickness and lower relative permittivity, while the second sub-dielectric layer has lesser thickness and higher relative permittivity. This segmentation allows the capacitor to achieve high voltage-sustaining capability without requiring a uniformly thick dielectric layer, thereby avoiding substrate warping and simplifying the fabrication process.
Solution Approach 2:
Different regions of the dielectric layer are assigned different properties: the first sub-dielectric layer provides mechanical support and basic insulation with greater thickness, while the second sub-dielectric layer provides enhanced electrical performance with higher relative permittivity in specific regions. This local differentiation optimizes both voltage-sustaining capability and fabrication ease without requiring uniform thickness throughout.
2Reliability
If the thickness of the dielectric layer is increased to enhance voltage-sustaining capability, then the breakdown voltage is improved, but substrate warping occurs
Solution Approach 1:
The dielectric layer is divided into sub-layers where the first sub-dielectric layer (greater thickness) provides mechanical support to prevent substrate warping, while the second sub-dielectric layer (lesser thickness with higher relative permittivity) provides the necessary electrical performance. This segmentation distributes stress more evenly across the substrate.
Solution Approach 2:
The dielectric structure uses composite materials with different properties: the first sub-dielectric layer uses materials optimized for mechanical stability and thickness, while the second sub-dielectric layer uses materials with higher relative permittivity for electrical performance. This composite approach achieves both mechanical stability (preventing warping) and electrical performance (high breakdown voltage).
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 breakdown voltage and voltage-sustaining capability of semiconductor devices while maintaining the same interconnection structure fabrication process, thus addressing the drawbacks of thicker dielectric layers.
Implementation Method 1
The relative permittivity of the intermediate dielectric layer is greater than the relative permittivity of the stacked dielectric layer
Data Source
AI summary
A method for fabricating a semiconductor device is provided and includes the following steps: providing a substrate; forming a lower electrode on the substrate; forming at least one sub-dielectric layer on the lower electrode; patterning the dielectric layer to form an intermediate dielectric layer, where the intermediate dielectric layer exposes a portion of the at least one sub-dielectric layer; forming a hole by etching the portion of the at least one sub-dielectric layer not covered by the intermediate dielectric layer; filling at least one plug into the hole; and forming an upper electrode on the intermediate dielectric layer.