Semiconductor Isolation Structure Void Reduction via Annealing
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Solution Overview
Problem
The increasing complexity and miniaturization of semiconductor integrated circuits pose challenges in manufacturing smaller isolation structures, leading to difficulties in achieving high manufacturing yield and operational performance due to void issues in trenches.
Innovation Solution
An annealing process is used to densify a first dielectric layer formed in a trench, converting it into a thinner, higher-density second dielectric layer, followed by a third dielectric layer to fill the trench, thereby enhancing the quality and yield of the isolation structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the trench is filled directly with dielectric material without annealing, then the manufacturing process is simpler and faster, but voids form in the dielectric layer reducing manufacturing yield
Solution Approach 1:
An annealing process is performed before filling the trench with dielectric material. This preliminary action densifies the dielectric layer and prevents void formation during subsequent filling operations, thereby improving manufacturing yield without significantly impacting overall process time
Solution Approach 2:
The annealing process changes the physical parameters of the dielectric layer by heating it to high temperature (typically 400-600°C), which densifies the material and reduces its porosity. This parameter change ensures proper filling and eliminates void issues during trench filling
2Quantity of substance
If the isolation structure size is reduced to meet higher integration requirements, then circuit density increases, but manufacturing precision becomes more difficult to achieve
Solution Approach 1:
The annealing process is performed as a preliminary step before trench filling to densify the dielectric layer and establish a stable foundation. This preliminary densification ensures that even in smaller, more densely packed isolation structures, the filling process proceeds without voids or defects, maintaining manufacturing precision
Solution Approach 2:
By changing the temperature parameter through annealing, the dielectric material achieves optimal density and mechanical properties. This parameter optimization enables precise manufacturing of smaller isolation structures with higher circuit density while maintaining quality standards
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 method reduces the likelihood of voids in the dielectric layer, improving the manufacturing yield and operational performance by ensuring a higher-density fill, which mitigates negative influences from subsequent high-temperature processes.
Implementation Method 1
An annealing process is performed to densify the first dielectric layer and convert the first dielectric layer into a second dielectric layer
Implementation Method 2
An annealing process is used to densify a first dielectric layer formed in a trench
Data Source
AI summary
A manufacturing method of an isolation structure includes the following steps. A semiconductor substrate is provided. A trench is formed in the semiconductor substrate. A first film forming process is performed to form a first dielectric layer conformally on the semiconductor substrate and conformally in the trench. An annealing process is performed to densify the first dielectric layer and convert the first dielectric layer into a second dielectric layer. A thickness of the second dielectric layer is less than a thickness of the first dielectric layer. A second film forming process is performed after the annealing process to form a third dielectric layer on the second dielectric layer and in the trench. The trench is filled with the second dielectric layer and the third dielectric layer.