Semiconductor ESD Protection via Internal Reference Voltage Generation

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Solution Overview

Problem

Semiconductor devices face challenges with electrostatic discharge (ESD) protection due to high parasitic capacitance and current leakage, particularly in the transmission path of the reference voltage, which can lead to defects and increased size of the semiconductor device.

Innovation Solution

The semiconductor device employs a unit gain buffer or internal reference voltage generator to produce an internal reference voltage, reducing the number of electrostatic discharge sensitive elements and thereby minimizing the need for internal electrostatic discharge protectors, which in turn reduces parasitic capacitance and current leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If internal electrostatic discharge protectors are disposed at the transmission path of the reference voltage to protect input buffers, then the input buffers are protected from electrostatic discharge, but the parasitic capacitance and current leakage increase

Engineering Contradiction:

Improveprotection from electrostatic dischargeVSAvoidparasitic capacitance and current leakage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the reference voltage from the external transmission path and generates it internally using a unit gain buffer. This removes the need for internal electrostatic discharge protectors at the input buffer transmission path, thereby eliminating the parasitic capacitance and current leakage associated with these protectors while maintaining protection through external protectors alone.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The unit gain buffer acts as an intermediary that generates an internal reference voltage, separating the reference voltage function from the external transmission path. This intermediary structure allows the system to maintain reference voltage functionality without requiring vulnerable transmission paths that need protection, thus reducing parasitic effects.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If internal electrostatic discharge protectors are disposed at the transmission path of the reference voltage, then electrostatic discharge protection is provided, but the area of the semiconductor device increases

Engineering Contradiction:

Improveprotection from electrostatic dischargeVSAvoidarea of electrostatic discharge protectors

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent extracts the reference voltage generation function from the external transmission path and implements it internally via a unit gain buffer. This eliminates the need for internal electrostatic discharge protectors at the input buffer path, thereby reducing the total area occupied by protection circuits while maintaining adequate protection through external protectors.

Inventive Principle:

Principle #2Taking out (Extraction)

3Productivity

If the gate oxide layer thickness is reduced to manufacture high performance semiconductor device, then the device performance and integration are improved, but the susceptibility to electrostatic discharge increases

Engineering Contradiction:

Improvedevice performance and integrationVSAvoidsusceptibility to electrostatic discharge

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the vulnerability of thin gate oxide layers to electrostatic discharge into a benefit by reconfiguring the reference voltage transmission path. By generating the reference voltage internally and eliminating unnecessary internal protectors, the design reduces parasitic capacitance that would otherwise exacerbate ESD susceptibility, thereby protecting the thin gate oxide structures while maintaining high performance.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS8274770B2Electrostatic discharge protection of semiconductor device

Publication Date: 2012.09.25 SK HYNIX INC

AI summary

A semiconductor device includes a pads for receiving a reference voltage and input signals from an external device, a unit gain buffer for receiving the reference voltage as an input, input buffers for identifying a corresponding one of the input signals based on an internal reference voltage outputted from the unit gain buffer, external electrostatic discharge protectors connected to a transmission path of the reference voltage and transmission paths of input signals, and internal electrostatic discharge protectors connected to the transmission path of the reference voltage and the transmission paths of the input signals.