Deep Trench Isolation With Thermal Corner Dielectric
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional isolation techniques for integrating different devices in a single chip, such as high voltage devices and logic circuit elements, face issues with potential breakdown voltage and reliability due to interference and latch-up problems.
Innovation Solution
The implementation of deep trench isolation (DTI) structures with a fill material and a dielectric layer, along with a thermal dielectric layer forming a thick top corner dielectric, effectively isolates different device regions in a semiconductor substrate, enhancing breakdown voltage and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional isolation techniques are used to isolate different device regions, then device isolation is achieved, but breakdown voltage and reliability are compromised
Solution Approach 1:
The isolation structure is divided into multiple segments: a deep trench isolation structure extending into the substrate, a first dielectric material filling the trench, a second dielectric material formed over the trench, and a thick top corner dielectric portion. This segmentation allows each layer to contribute differently to the overall isolation performance and breakdown voltage margin.
Solution Approach 2:
The patent introduces a vertical dimension to the isolation structure by forming a thick top corner dielectric portion that extends upward from the trench region. This adds a third dimension (vertical thickness) to the isolation approach, creating an overlapping dielectric configuration that enhances breakdown voltage without increasing lateral footprint.
2Reliability
If deep trench isolation structure with thick top corner dielectric is formed, then breakdown voltage margin is improved, but manufacturing process complexity increases
Solution Approach 1:
The deep trench isolation structure and dielectric materials are formed in advance before subsequent device fabrication steps. This preliminary action establishes the isolation framework early, providing a stable foundation that simplifies later processing and reduces the risk of defects affecting final device performance.
Solution Approach 2:
The patent employs composite dielectric structures with at least two different dielectric materials: a first dielectric material filling the trench and a second dielectric material formed over the trench. This composite approach allows optimization of different layers for different functions, improving overall reliability while managing manufacturing complexity.
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 DTI structure with a thicker top corner dielectric improves the breakdown voltage margin and effectively isolates various device regions, reducing reliability risks and allowing for more process margin in dielectric formation and etch back processes.
Implementation Method 1
Local oxidation of the substrate is performed over the DTI structure to form a thermal dielectric layer which overlaps the DTI structure
Data Source
AI summary
Semiconductor devices and methods of forming thereof are disclosed. A substrate with different device regions defined in the substrate is provided. A deep trench isolation (DTI) structure is formed in the substrate to isolate the different device regions. The DTI structure includes a fill material and a dielectric layer surrounding the fill material in the DTI structure. Local oxidation of the substrate is performed over the DTI structure to form a thermal dielectric layer which overlaps the DTI structure. The thermal dielectric layer which overlaps the DTI structure forms a thick top corner dielectric in the DTI structure.