ESD Protection Structure With Parallel Low-Trigger Discharge Paths

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Solution Overview

Problem

Existing electrostatic discharge protection devices have high trigger voltages, making them unsuitable for protecting semiconductor devices like DRAM, as they fail to discharge electrostatic charges before the IC is damaged.

Innovation Solution

The electrostatic discharge protection device incorporates a transistor structure with heavily-doped regions and wells in a P-type substrate, forming low impedance channels to reduce trigger voltage and enhance discharge capability, utilizing parasitic transistors and diodes to create multiple discharge paths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing electrostatic discharge protection devices are used, then the device structure is simple, but the trigger voltage is high and unsuitable for protecting semiconductor devices like DRAM

Engineering Contradiction:

Improveelectrostatic discharge protection capabilityVSAvoidtrigger voltage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The protection device is divided into multiple parallel discharge paths: a first discharge path including a first diode and first transistor, and a second discharge path including a second diode and second transistor. This segmentation allows different paths to activate at different voltage levels, with the first path providing early protection at lower voltages and the second path handling higher voltage events, thereby reducing the overall trigger voltage while maintaining comprehensive protection capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The device employs dynamic characteristics through the use of transistors with different threshold voltages and diodes with different breakdown voltages. The first transistor has a lower threshold voltage than the second transistor, and the first diode has a lower breakdown voltage than the second diode. This dynamic structure enables the protection device to adaptively respond to different voltage levels, activating appropriate discharge paths based on the magnitude of the electrostatic discharge event.

Inventive Principle:

Principle #15Dynamics

2Productivity

If existing electrostatic discharge protection devices are used, then the device complexity is low, but the discharge capability is insufficient for high-speed electrostatic discharge protection

Engineering Contradiction:

Improvedischarge speedVSAvoiddevice structure

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The device merges multiple discharge mechanisms (diode breakdown and transistor conduction) into a unified protection structure. By combining parallel diodes with parallel transistors, the device achieves high discharge capability through multiple simultaneous conduction paths while maintaining a relatively compact structure suitable for integrated circuit implementation.

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

This design effectively reduces the trigger voltage and improves the electrostatic discharge protection capability by discharging electrostatic current through low impedance paths, preventing IC damage in electrostatic environments.

Implementation Method 1

an electrostatic discharge protection device is usually provided in the IC, and the IC is protected by releasing electrostatic charges through a low impedance channel formed by the electrostatic discharge protection device

Methodology Applied

Scientific EffectElectrostatic Discharge: Electrostatic Discharge

Implementation Method 2

utilizing parasitic transistors and diodes to create multiple discharge paths

Methodology Applied

Scientific EffectParasitic Transistor Effect:

Implementation Method 3

The electrostatic discharge protection device generally includes one or more of a resistor, a diode, a triode, a metal oxide semiconductor (MOS) transistor, or a semiconductor conductor rectifier (SCR)

Methodology Applied

Scientific EffectDiode Conduction: Diode

Data Source

PatentUS12125843B2Electrostatic discharge protection device

Publication Date: 2024.10.22 CHANGXIN MEMORY TECH INC

AI summary

The present disclosure provides an electrostatic protection device, and relates to the technical field of semiconductors. The electrostatic discharge protection device includes a first P-type heavily-doped region, a first N-type heavily-doped region, a second N-type heavily-doped region, a second P-type heavily-doped region, and a third N-type heavily-doped region. The first P-type heavily-doped region and the first N-type heavily-doped region are located in a P well, the second P-type heavily-doped region and the third N-type heavily-doped region are located in a first N well, one part of the second N-type heavily-doped region is located in the P well, the other part of the second N-type heavily-doped region is located in first N well, and the P well and the first N well are adjacent to each other and both located in the P-type substrate.