Multi-Layered Isolation Trench Structure for Semiconductor Device
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Solution Overview
Problem
The challenge in semiconductor manufacturing lies in forming reliable semiconductor devices at increasingly smaller sizes, where the complexity of fabrication processes increases due to decreasing feature sizes, leading to difficulties in maintaining device alignment and reducing deformation of active regions during annealing.
Innovation Solution
The formation of an insulating layer with a specific thickness and ratio to a liner layer, using different deposition methods for the insulating and isolation layers, helps reduce deformation of the isolation layer during annealing, thereby improving the alignment of subsequent processes and device yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feature sizes continue to decrease to increase functional density, then production efficiency improves and costs降低, but fabrication process difficulty increases and device reliability deteriorates
Solution Approach 1:
The isolation structure is divided into multiple layers: a first isolation layer (liner layer) directly in the trench, and a second isolation layer (insulating layer) formed over the first isolation layer. This segmentation allows each layer to perform specific functions - the liner layer provides immediate isolation and the insulating layer provides additional deformation resistance during annealing, thereby maintaining device reliability at smaller feature sizes
Solution Approach 2:
The isolation structure uses composite materials with different properties - the liner layer (first isolation layer) and the insulating layer (second isolation layer) have different material compositions and thicknesses. The insulating layer has greater thickness and higher deformation resistance, creating a composite structure that optimizes both isolation performance and structural stability during fabrication processes
2Manufacturing precision
If feature sizes continue to decrease, then functional density increases, but manufacturing precision deteriorates due to alignment difficulties
Solution Approach 1:
The liner layer (first isolation layer) is formed in the trench before the insulating layer (second isolation layer) is deposited. This preliminary action establishes a stable base structure that defines the trench boundaries early in the process, providing a reference framework that simplifies subsequent alignment operations and maintains manufacturing precision
Solution Approach 2:
The liner layer acts as an intermediary between the trench substrate and the insulating layer. It provides a stable intermediate structure that facilitates the formation of the insulating layer with proper alignment, thereby reducing the complexity of direct trench-to-insulating-layer alignment and improving overall manufacturing precision
3Reliability
If annealing process is performed to treat semiconductor structures, then material properties are improved, but deformation of isolation layers and active regions occurs
Solution Approach 1:
The insulating layer is designed with greater thickness and higher deformation resistance parameters compared to the liner layer. By changing these physical parameters, the insulating layer can withstand the thermal and mechanical stresses of the annealing process without deforming, while still allowing the liner layer to provide its isolation function. This parameter optimization enables annealing to improve material properties without causing unacceptable isolation layer deformation
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 effectively reduces deformation of trenches and active regions, enhancing the accuracy of subsequent processes and improving the yield of semiconductor devices by maintaining precise alignment and structure integrity.
Implementation Method 1
a liner layer covering an inner wall and a bottom surface of the trench
Implementation Method 2
reduce the deformation of the isolation layer during an annealing process
Implementation Method 3
A first thickness of the insulating layer is greater than a second thickness of the liner layer
Implementation Method 4
an isolation layer over the insulating layer and filling the trench
Data Source
AI summary
A semiconductor device structure is provided. The semiconductor device structure includes a substrate having a first trench between a first active region and a second active region of the substrate. The semiconductor device structure includes an isolation structure in the first trench. The isolation structure includes a liner layer, an insulating layer, and an isolation layer. The liner layer covers an inner wall and a bottom surface of the first trench. The insulating layer covers the liner layer and has a second trench in the first trench. The isolation layer is over the insulating layer and fills the second trench. A first thickness of the insulating layer is greater than a second thickness of the liner layer.