Segmented ESD Protection Layout for Low-Leakage MOSFET Terminals

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Solution Overview

Problem

Conventional semiconductor devices, such as MOSFETs, are prone to Electrostatic Discharge (ESD) failures including junction damage, gate oxide damage, and metallization burnout, which are thermally induced and result in high leakage currents and structural failures.

Innovation Solution

An ESD protection semiconductor device is integrated into the semiconductor body, featuring elongated ESD regions with multiple diode regions and isolated floating strips, which provide effective connections between diode regions, reducing the active area and minimizing leakage current, and is designed to be aligned with the semiconductor device's terminals to enhance protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional ESD protection devices are used, then ESD protection is provided, but leakage current increases and active area decreases

Engineering Contradiction:
ImproveESD protectionVSAvoidleakage current
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The ESD protection device is segmented into multiple diode regions (first, second, third, and fourth diode regions) arranged in a specific pattern. This segmentation allows the device to distribute the ESD protection function across multiple smaller units, reducing the leakage current path and minimizing the impact on active area while maintaining effective ESD protection capability.

Inventive Principle:
Principle #1Segmentation

2Reliability

If traditional ESD protection devices are used, then ESD protection is provided, but active area decreases

Engineering Contradiction:
ImproveESD protectionVSAvoidactive area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The ESD protection device utilizes a vertical dimension by extending diode regions from the first major surface into the semiconductor body. This three-dimensional arrangement allows the ESD protection function to be achieved without proportionally increasing the planar footprint, thereby preserving more active area on the chip surface while maintaining effective ESD protection.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If diode regions are spaced apart, then ESD protection effectiveness improves, but device complexity increases

Engineering Contradiction:
ImproveESD protection effectivenessVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The ESD protection device merges multiple diode regions into a unified structure with shared connections. The first and second diode regions share the floating terminal, and the third and fourth diode regions share another floating terminal, reducing the overall complexity compared to completely separate diode structures while maintaining effective ESD protection through the spaced-appart arrangement.

Inventive Principle:
Principle #5Merging (Combining)

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 solution effectively reduces leakage current to nanoAmpere levels, provides robust ESD protection by minimizing the diode span, and maintains the functionality of the semiconductor device by isolating the ESD protection structure from the main device, thus preventing thermal-induced failures.

Implementation Method 1

An Electrostatic Discharge, ESD, protection semiconductor device for providing ESD protection between a first and a second terminal of another semiconductor device

Methodology Applied
Scientific EffectElectrostatic Discharge: Electrostatic Discharge

Implementation Method 2

a first diode region of a second conductivity type, wherein the first diode region is connected to the first ESD terminal; a second diode region of the second conductivity type, spaced apart from said first diode region

Methodology Applied
Scientific Effectpn junction breakdown: Avalanche Breakdown

Data Source

PatentEP4350769A1An electrostatic discharge, ESD, protection semiconductor device for providing ESD protection between a first and a second terminal of another semiconductor device, as well as a corresponding metal oxide semiconductor, MOS, field effect transistor, FET, and a related method
Publication Date: 2024.04.10 NEXPERIA BV
  • EP4350769A1 patent drawingFigure 1
  • EP4350769A1 patent drawingFigure 2
  • EP4350769A1 patent drawingFigure 3

AI summary

An Electrostatic Discharge, ESD, protection semiconductor device for providing ESD protection between a first and a second terminal of another semiconductor device, the ESD protection device comprising a semiconductor body having a first major surface, wherein the semiconductor device further comprises a first ESD terminal arranged to be connected to a first terminal of the other semiconductor device, a second ESD terminal arranged to be connected to a second terminal of the other semiconductor device, and a floating terminal.