Trench Shield Electrode Structure for Semiconductor Devices

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Solution Overview

Problem

Existing semiconductor devices with shield electrodes face challenges in integrating these electrodes with other structures, particularly in non-planar topographies and die area consumption, which affects cost and manufacturability, and there is a need for improved performance and reliability.

Innovation Solution

A semiconductor device configuration that uses a single metal layer to connect control and shield electrodes, with shield electrodes placed offset from the center, reducing die area usage and enabling deeper submicron lithography, and employing thicker insulator layers to enhance oxide breakdown voltage performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If shield electrodes are integrated with other device structures, then device performance is improved, but device complexity increases

Engineering Contradiction:

Improvedevice performanceVSAvoidstructure integration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the shield electrode formation with the existing trench gate formation process. The shield electrode is formed within the same trench structure as the gate electrode, eliminating the need for separate processing steps. This merging of functions reduces overall device complexity while maintaining the performance benefits of shield electrodes.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The trench structure serves multiple functions: it acts as both the gate electrode holder and the shield electrode holder. This multi-functionality reduces the number of separate components needed, simplifying the overall device structure while providing both gate control and capacitance reduction functions.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If shield electrodes are added to reduce gate-to-drain capacitance, then switching performance is improved, but manufacturing complexity increases

Engineering Contradiction:

Improveswitching performanceVSAvoidmanufacturing process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The shield electrode is formed preliminary to the gate electrode within the same trench structure. By preparing the shield electrode position first during trench formation, subsequent gate electrode fabrication can proceed without additional masking or alignment steps, simplifying the manufacturing process.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If shield electrodes are positioned to optimize performance, then capacitance reduction is improved, but die area consumption increases

Engineering Contradiction:

Improvecapacitance reductionVSAvoiddie area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent transitions from planar electrode positioning to three-dimensional trench-based positioning. By placing the shield electrode vertically within the trench below the gate electrode, the design utilizes the vertical dimension rather than consuming additional horizontal die area, maintaining capacitance reduction benefits while preserving compact device footprint.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS7915672B2Semiconductor device having trench shield electrode structure

Publication Date: 2011.03.29 SEMICON COMPONENTS IND LLC

AI summary

In one embodiment, a structure for a semiconductor device having a trench shield electrode includes a control pad, control runners, shield runners, and a control/shield electrode contact structure. The structure is configured to use a single level of metal to connect the various components. In another embodiment, a shield runner is placed in an offset from center configuration.