Deep Trench Isolation Liner Patterning for Substrate Plug Formation
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Solution Overview
Problem
Existing Deep Trench Insulation (DTI) technologies face challenges in selectively removing insulation liner at the bottom of trenches while maintaining it on the sidewalls, which is crucial for forming substrate plugs and field plate electrodes in high-voltage semiconductor devices.
Innovation Solution
A process involving the formation of first and second trenches with different depths and widths, followed by the deposition of an insulation liner and a halogen-based polymer layer. The polymer layer is used as an etch mask to selectively remove the insulation liner at the bottom of the first trench, while maintaining it in the second trench, allowing for the formation of a substrate plug and a field plate electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a uniform insulation liner is formed in both deep and shallow trenches, then complete electrical isolation is achieved, but selective access to the bottom of the deep trench for substrate plug formation becomes difficult
Solution Approach 1:
The patent applies local quality by creating different liner configurations in different regions. The insulation liner is made discontinuous at the bottom of the deep trench (first trench) while remaining continuous in the shallow trench (second trench). This is achieved by controlling the etch process to remove the liner selectively at the bottom of the deep trench, allowing the liner to be present or absent at different locations according to local requirements.
Solution Approach 2:
The patent segments the insulation liner into continuous and discontinuous portions. The liner is segmented such that it provides complete coverage in the shallow trench for electrical isolation, while being selectively removed at the bottom of the deep trench to allow substrate plug formation. This segmentation allows different functional requirements to be met in different parts of the same trench structure.
2Ease of manufacture
If the insulation liner is completely removed from the bottom of the deep trench, then substrate plug formation is enabled, but electrical isolation reliability is compromised
Solution Approach 1:
The patent applies local quality by creating different liner configurations in different regions. The insulation liner is made discontinuous at the bottom of the deep trench (first trench) while remaining continuous in the shallow trench (second trench). This is achieved by controlling the etch process to remove the liner selectively at the bottom of the deep trench, allowing the liner to be present or absent at different locations according to local requirements.
3Adaptability or versatility
If different trench depths and widths are used for substrate plug and field plate electrode, then functional requirements are met, but selective processing becomes more complex
Solution Approach 1:
The patent applies preliminary action by forming the insulation liner in both trenches before selectively removing it from the deep trench. The liner is first deposited to provide complete coverage, then a subsequent etch process selectively removes the liner only from the bottom of the deep trench. This preliminary formation of the liner simplifies the overall process by establishing a baseline configuration that can then be selectively modified.
Solution Approach 2:
The patent applies local quality by creating different liner configurations in different regions. The insulation liner is made discontinuous at the bottom of the deep trench (first trench) while remaining continuous in the shallow trench (second trench). This is achieved by controlling the etch process to remove the liner selectively at the bottom of the deep trench, allowing the liner to be present or absent at different locations according to local requirements.
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 process enables the efficient formation of substrate plugs and field plate electrodes with precise control over the insulation liner, enhancing the electrical isolation and performance of high-voltage semiconductor devices.
Implementation Method 1
depositing a halogen-based polymer layer that covers at least an upper portion of the insulation material in the first trench without covering a portion insulation material at the bottom of the first trench and further covers the insulation material at the sidewalls and bottom of the second trench
Data Source
AI summary
A deep trench isolation structure is formed in a semiconductor material body by opening first and second trenches. The sidewalls and bottoms of the first and second trenches are then lined with an insulating material. A halogen-based polymer material is then deposited to cover at least an upper portion of the insulation material in the first trench without covering a portion insulation material at the bottom of the first trench and further cover the insulation material at the sidewalls and bottom of the second trench. An etch process is then used to remove the portion of the insulation material at the bottom of the first trench and the polymer material is removed from both the first trench and second trench. The trenches are then filled with polysilicon to form a substrate plug in the first trench and a field plate electrode in the second trench.