Backside Shield Geometry for Plasma Etch Edge Control
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Solution Overview
Problem
The etch edge effect in partial plasma etch processes leads to non-uniformity and damage at the edges of semiconductor substrates, affecting device performance and yield.
Innovation Solution
A backside shield is mounted around the substrate to control the etch edge effect by strategically configuring its material, position, and angle relative to the substrate, and adjusting its height offset to optimize plasma processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional plasma processing techniques are used, then the etching process can be performed, but etch edge effects cause non-uniformity and damage at substrate edges
Solution Approach 1:
A backside shield is introduced as an intermediary component positioned at the rear of the substrate. This shield mediates the plasma interaction by providing a controlled surface that modifies ion bombardment patterns and plasma flow, thereby reducing edge effects on the substrate while maintaining effective etching across the surface.
Solution Approach 2:
The invention changes physical parameters by introducing a backside shield with specific geometric configurations (position, height, diameter). These parameter changes alter the plasma distribution and ion bombardment characteristics, transforming the etching process from one that produces edge effects to one that achieves uniform etching across the substrate.
2Manufacturing precision
If process parameters are adjusted to minimize edge non-uniformity, then etch uniformity improves, but process complexity increases
Solution Approach 1:
Instead of complexly adjusting multiple process parameters (gas composition, pressure, power, temperature), the invention introduces a backside shield as a physical intermediary that achieves etch uniformity through its geometric configuration alone, simplifying the overall process control.
Solution Approach 2:
The invention transitions from adjusting operational parameters (pressure, power, temperature, gas flow) to controlling geometric parameters of the backside shield (position, height, diameter). This parameter transformation simplifies process optimization since geometric parameters are more stable and easier to control than plasma process parameters.
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 etch uniformity across the substrate surface, improving device performance and fabrication efficiency by minimizing inconsistencies at the edge.
Implementation Method 1
generating, based on the process recipe, a plasma at a plasma source, and directing, based on the process recipe, the plasma into the processing chamber and towards outer surfaces of the substrate and the backside shield
Data Source
AI summary
A method for controlling an etch edge effect in a partial plasma etch process includes loading a substrate in a processing chamber with a backside shield disposed around the substrate, and configuring the backside shield according to a calibration specific to one or more process recipes. The method further includes generating, based on the process recipe, a plasma at a plasma source, and directing, based on the process recipe, the plasma into the processing chamber and towards outer surfaces of the substrate and the backside shield using a nozzle. And the method further includes processing the substrate by exposing the substrate and the backside shield to the plasma based on the one or more process recipes.