Semiconductor Device Trench Isolation for Miniaturization

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Solution Overview

Problem

The existing semiconductor devices face challenges in reducing the size of semiconductor elements due to the wide isolation regions required to prevent punch-through phenomena, which increases the lateral width and hinders miniaturization.

Innovation Solution

A semiconductor device structure featuring an epitaxial layer with trenches surrounding a buried layer and insulation films within these trenches, which reduces the width of isolation regions and prevents leak current, allowing for smaller device sizes without compromising breakdown voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the isolation regions are made wider to prevent punch-through phenomenon, then the insulation resistance is improved, but the device size increases

Engineering Contradiction:

Improveinsulation resistanceVSAvoiddevice size

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent transitions from two-dimensional planar isolation regions to three-dimensional trench structures that extend vertically into the semiconductor substrate. By utilizing the depth dimension, the isolation effect is enhanced without increasing the lateral footprint, thereby preventing punch-through while maintaining compact device dimensions.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The trench isolation structures are nested within the semiconductor substrate, with insulation films positioned within the trenches. This nested configuration allows the isolation function to be embedded within the existing device structure, providing effective electrical isolation without adding to the overall device area.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Reliability

If the isolation regions are made wider to prevent punch-through phenomenon, then the element breakdown voltage is improved, but the manufacturing complexity increases

Engineering Contradiction:

Improveelement breakdown voltageVSAvoidisolation structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The isolation structure is segmented into discrete trench regions that are formed and filled independently. This segmentation allows for standardized manufacturing processes where trenches are etched at specific locations and filled with insulation material, simplifying the overall fabrication compared to creating large continuous isolation regions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the geometric parameters of the isolation structure by introducing vertical depth through trench formation. Instead of increasing lateral dimensions, the isolation effectiveness is achieved by modifying the depth parameter, which can be controlled through etching process parameters rather than requiring complex mask patterns.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS7655974B2Semiconductor device

Publication Date: 2010.02.02 SEMICON COMPONENTS IND LLC

AI summary

A semiconductor device that reduces the width of an isolation region between semiconductor elements. The semiconductor device includes a semiconductor substrate, an epitaxial layer formed on the semiconductor substrate, a buried layer formed between the semiconductor substrate and the epitaxial layer, a first trench formed in the epitaxial layer so as to surround the buried layer, and an insulation film formed in the first trench.