Trench Termination Structure With Single-Step Insulation Deposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing trench transistor layouts require multiple insulation layer deposition steps to create thick insulation in termination regions, which is costly and limits the use of single electrode designs, making them impractical for certain devices.
Innovation Solution
A semiconductor device design with termination trench structures featuring insulation layers of similar thickness to gate trench insulation layers, allowing for efficient creation of termination regions in single gate polycrystalline electrode transistors, using a single formation step for insulation layers and incorporating buried guard rings and blanket or pillar-like body regions to manage electric field distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple insulation layer deposition steps are used to create thick insulation in termination regions, then breakdown voltage and reliability are improved, but production cost and manufacturing complexity increase
Solution Approach 1:
The patent combines the gate trench insulation layer and termination trench insulation layer into a single continuous insulation layer formed in one deposition step. This merging eliminates the need for separate deposition processes for different regions, reducing manufacturing complexity and cost while maintaining the required insulation thickness for breakdown voltage performance.
Solution Approach 2:
The single continuous insulation layer serves multiple functions simultaneously: it provides electrical insulation for the gate electrode, provides electrical insulation for the termination electrode, and establishes the appropriate electric field distribution. This multi-functional approach eliminates the need for region-specific insulation layers while maintaining all necessary electrical characteristics.
2Reliability
If multiple insulation layer deposition steps are used to create thick insulation in termination regions, then electric field distribution is optimized, but manufacturing process complexity increases
Solution Approach 1:
The patent merges the formation of gate trench insulation and termination trench insulation into a single continuous insulation layer deposited in one process step. This eliminates the need for multiple deposition steps, masking, and etching operations that would otherwise be required, significantly reducing manufacturing process complexity while maintaining optimized electric field distribution.
Solution Approach 2:
While the insulation layer is continuous, the underlying trench structures (gate trenches and termination trenches) are segmented and positioned at different locations. This spatial segmentation allows the single insulation layer to serve different functional regions with different electrical requirements, optimizing electric field distribution without requiring separate insulation layers.
3Reliability
If thick insulation layer is created in termination region, then breakdown voltage improves, but production time and process steps increase
Solution Approach 1:
The patent combines the formation of all insulation layers into a single deposition process, eliminating sequential deposition steps. This merging reduces production time while maintaining the necessary insulation thickness in termination regions for achieving the required breakdown voltage performance.
Solution Approach 2:
The single continuous insulation layer is formed in advance during the gate trench insulation formation step, before subsequent processing steps. This preliminary action ensures that both gate and termination regions have the required insulation thickness from the outset, eliminating the need for additional deposition steps later in the process.
Data Source
AI summary
A semiconductor device and method for making the structure thereof are disclosed. The device includes a semiconductor substrate composition having an active region, a transition region and a first termination region. An active trench gate structure is disposed in the active region and a first termination trench structure is disposed in the first termination region and laterally separated from the active trench by the transition region having a transition trench structure. The first termination trench sidewall insulation layer of the first termination trench structure has a similar thickness as a transition trench sidewall insulation layer of the transition trench structure and a gate sidewall insulation layer of the active trench gate structure.