Deep Trench Capacitor Corner Oxide Compensation
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Solution Overview
Problem
Conventional deep trench capacitors face issues with deteriorating breakdown voltage characteristics due to electric field concentration in the corner areas of the oxide film, which is caused by non-uniform thickness resulting from thermal oxidation.
Innovation Solution
A deep trench capacitor with a compensation film formed by a low-pressure radical process is used to compensate for the thin thickness in bottom corner areas of the oxide film, while also flattening the widthwise sidewalls of the deep trench, thereby improving breakdown voltage and gap-fill characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If thermal oxidation process is used to form oxide film in deep trench, then oxide film can be formed on the trench walls, but the oxide film thickness becomes non-uniform with thin corner areas causing electric field concentration
Solution Approach 1:
The patent applies local quality by forming a compensation film specifically in the corner areas where the oxide film is thin, rather than uniformly throughout the entire trench. This targeted approach compensates for the non-uniform oxide film thickness only where needed (at the corners), preventing electric field concentration while maintaining the benefits of thermal oxidation elsewhere.
Solution Approach 2:
The compensation film is formed before the oxide film deposition process. This preliminary action ensures that when the oxide film is subsequently formed by thermal oxidation, the corner areas already have an additional layer that compensates for the expected thinness, thereby preventing electric field concentration issues from the outset.
2Manufacturing precision
If conventional thermal oxidation is used, then oxide film formation is achieved, but gap-fill characteristics deteriorate due to non-uniform thickness distribution
Solution Approach 1:
The compensation film is selectively formed in the corner areas of the trench where gap-fill issues occur, rather than uniformly across all surfaces. This local compensation addresses the specific gap-fill problems in corner regions while maintaining proper oxide film formation on the trench walls through thermal oxidation.
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
The proposed solution effectively prevents the deterioration of breakdown voltage characteristics and enhances the gap-fill characteristics by ensuring a more uniform thickness of the oxide film and reducing electric field concentration in the corner areas.
Implementation Method 1
the compensation film may be formed by a low-pressure radical process
Implementation Method 2
O2 diffuses toward an Si substrate 901 by a thermal oxidation process to form an SiO2 oxide film
Data Source
AI summary
Proposed are a deep trench capacitor and a method of manufacturing the same that compensate for a thin thickness in bottom corner areas of an oxide film (e.g., SiO2) grown by thermal oxidation in a deep trench to prevent a deterioration in breakdown voltage characteristics due to electric field concentration in the corner areas of the oxide film, or that relatively flatten widthwise inner sidewalls of the deep trench to improve the breakdown voltage characteristics and gap-fill characteristics of a device.