Semiconductor Element ESD Protection via Clamp Diode
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Solution Overview
Problem
High-voltage semiconductor devices face challenges in electrostatic discharge (ESD) protection due to concentrated ESD current at the surface or drain edge, which can lead to physical destruction and unwanted noise, exacerbated by low on-state resistance and high breakdown voltage characteristics.
Innovation Solution
A semiconductor element design featuring a diode collocated with a metal oxide semiconductor (MOS) structure, including specific doping regions and a gate layer configuration that provides enhanced ESD protection by forming equivalent bipolar junction transistors and clamp diodes, allowing for effective ESD current diversion and voltage management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the on-state resistance is reduced to improve device performance, then the ESD current concentrates more at the surface or drain edge, but this increases the risk of physical destruction and reduces ESD protection
Solution Approach 1:
A clamp diode is introduced as an intermediary protective element connected between the drain and source terminals. The diode activates during ESD events to divert excess current away from vulnerable surface regions, protecting the main device while allowing normal operation to proceed through the low-resistance path
Solution Approach 2:
The device structure is segmented into multiple functional regions including lightly-doped and heavily-doped drain regions, source regions, and a separately controllable clamp diode. This segmentation allows independent optimization of the conduction path (low resistance) and the protection mechanism (current diversion) without compromising either function
2Power
If the breakdown voltage is increased to improve high-voltage performance, then the trigger voltage becomes higher than breakdown voltage, but this exposes internal circuitry to damage risk before ESD protection activates
Solution Approach 1:
The clamp diode's activation voltage is dynamically set to be lower than the main device's breakdown voltage through specific doping configurations. This creates a staged protection scheme where the diode activates first to handle ESD events, while the main device remains protected and can handle higher voltage stresses during normal operation
3Reliability
If additional masks and processes are used to create larger diodes or increase surface rules for ESD protection, then ESD protection improves, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The clamp diode is merged with the existing MOSFET structure by sharing common regions (source and drain terminals) and using the same fabrication process steps. The diode forms naturally from the doping profiles already required for the main device, eliminating the need for separate ESD protection structures and reducing overall complexity
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 proposed semiconductor element effectively diverts ESD current and manages voltage to prevent damage, offering improved ESD protection without increasing on-state resistance or altering the device's original operating functions, thus enhancing the reliability of high-voltage semiconductor devices.
Implementation Method 1
provides an excellent ESD protection... forming equivalent bipolar junction transistors and clamp diodes
Implementation Method 2
A semiconductor element design featuring a diode collocated with a metal oxide semiconductor (MOS) structure
Data Source
AI summary
A semiconductor element and a manufacturing method and an operating method of the same are provided. The semiconductor element includes a substrate, a first well, a first heavily doping region, at least a second heavily doping region, a gate layer, a third heavily doping region, and a fourth heavily doping region. The first well and the third heavily doping region are disposed on the substrate. The first and fourth heavily doping regions are disposed in the first well. The second heavily doping region is disposed in the first heavily doping region. The gate layer is disposed on the first well. The first, third, and fourth heavily doping regions having a first type doping are separated from one another. The first well and the second heavily doping region have a second type doping complementary to the first type doping.