Backside ESD Protection Circuit With Shared Taps for Lower Clamping

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Solution Overview

Problem

Miniaturized integrated circuits are increasingly susceptible to electrostatic discharge (ESD) due to thinner dielectric thicknesses and lower dielectric breakdown voltages, leading to potential electronic circuit damage.

Innovation Solution

An ESD protection circuit is implemented, comprising a first diode and a second diode coupled to an input/output pad, and an ESD clamp circuit with signal tap regions shared with the diodes, reducing area occupation and signal taps, resulting in lower resistance and faster operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If miniaturization process is applied to reduce device size and power consumption, then device functionality and speed are improved, but susceptibility to electrostatic discharge increases due to thinner dielectric thicknesses and lower breakdown voltages

Engineering Contradiction:

Improvedevice functionality and speedVSAvoidsusceptibility to electrostatic discharge

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The ESD protection circuit is activated before ESD events occur to prevent damage. The circuit proactively establishes protective pathways and monitoring mechanisms in advance, detecting voltage anomalies and preparing discharge routes before actual ESD strikes the miniaturized circuit, thereby protecting against the increased susceptibility caused by thinner dielectrics

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The ESD protection circuit acts as an intermediary between the external environment and the miniaturized integrated circuit. It introduces protective components (such as clamp circuits and discharge pathways) that mediate ESD events, diverting harmful electrostatic energy away from the vulnerable thin dielectric structures while allowing normal operation to proceed

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If ESD protection circuit is added to protect against electrostatic discharge, then circuit reliability is improved, but device area occupation increases

Engineering Contradiction:

Improvecircuit reliabilityVSAvoiddevice area occupation

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The ESD protection circuit merges protective functions with existing circuit structures. By integrating ESD clamp circuits, diodes, and discharge pathways into the available space around the IO pad and utilizing shared signal tap regions, the design achieves comprehensive ESD protection while minimizing additional area occupation in the miniaturized device

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The ESD protection circuit components serve multiple functions: the clamp circuit provides both voltage clamping and discharge pathways, diodes offer bidirectional protection, and signal tap regions serve both normal circuit operation and ESD detection. This multi-functionality reduces the total area required for protection while maintaining high reliability

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If ESD protection circuit with multiple signal taps is used to provide comprehensive protection, then ESD discharge capability is improved, but device area occupation and resistance increase

Engineering Contradiction:

ImproveESD discharge capabilityVSAvoiddevice area occupation

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The ESD protection circuit merges multiple protective functions into shared signal tap regions. By having diodes and clamp circuits share common tap regions, the design reduces the total number of discrete signal taps required, thereby decreasing device area occupation while maintaining comprehensive ESD discharge capability through the integrated protective pathways

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 ESD protection circuit effectively mitigates ESD events by providing a lower clamping voltage and faster discharge, enhancing the reliability of miniaturized integrated circuits.

Implementation Method 1

electrostatic discharge (ESD) events due to various factors, such as thinner dielectric thicknesses and associated lowered dielectric breakdown voltages. ESD is one of the causes of electronic circuit damage

Methodology Applied

Scientific EffectElectrostatic Discharge: Electrostatic Discharge

Data Source

PatentUS11862960B2Electrostatic discharge (ESD) protection circuit and method of operating the same

Publication Date: 2024.01.02 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

An electrostatic discharge (ESD) protection circuit includes a first diode, a second diode, an ESD clamp circuit and a first conductive structure on a backside of a semiconductor wafer, and being coupled to the first voltage supply. The first diode is in the semiconductor wafer, and coupled between an IO pad and a first node. The second diode is in the semiconductor wafer, coupled to the first diode and coupled between the IO pad and a second node. The ESD clamp circuit is in the semiconductor wafer, coupled between the first node and the second node, and further coupled to the first and second diode. The ESD clamp circuit includes a first signal tap region in the semiconductor wafer that is coupled to a first voltage supply. The first diode is coupled to and configured to share the first signal tap region with the ESD clamp circuit.