Field-Plate SCR Structure for Compact High-Voltage ESD
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for achieving high voltage operation in electric systems using stacked low voltage ESD devices result in increased footprint and turn-on resistance, making them inefficient for small form factor applications.
Innovation Solution
A silicon controlled rectifier (SCR) structure with field plates surrounding P-wells, isolated by an N-well and further isolated by LOCOS or shallow trench isolation structures, which allows for high breakdown voltage and efficient electrostatic discharge protection in a compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If stacked low voltage ESD devices are used to achieve high voltage operation capability, then the ESD device can sustain high voltage, but the ESD device footprint is multiplied by the stacking number
Solution Approach 1:
The device is segmented into multiple functional regions including a first region with first ESD protection devices, a second region with second ESD protection devices, and a third region with a third ESD protection device. This segmentation allows the device to achieve high voltage sustain capability through distributed protection mechanisms while maintaining a compact overall footprint by organizing these segments efficiently in the semiconductor structure.
2Reliability
If multiple ESD devices are stacked to achieve high voltage operation, then high voltage capability is achieved, but the turn-on resistance increases
Solution Approach 1:
Multiple ESD protection devices are merged into a single integrated SCR structure where first ESD protection devices, second ESD protection devices, and a third ESD protection device are combined in a unified semiconductor device. This merging approach maintains high voltage operation capability while reducing the overall turn-on resistance compared to stacked configurations, as the merged structure allows for optimized current paths and reduced series resistance.
3Reliability
If conventional stacked ESD devices are used, then high voltage capability is achieved, but the device complexity increases due to multiple stacking layers
Solution Approach 1:
The complex stacked configuration is extracted and replaced with a simplified planar or partially integrated structure. The first ESD protection devices, second ESD protection devices, and third ESD protection device are arranged in a manner that reduces structural complexity while maintaining high voltage capability. This extraction of the stacking concept into a more distributed, integrated layout reduces device complexity and facilitates easier manufacturing.
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 SCR structure achieves high breakdown voltage and efficient ESD protection with a smaller footprint, capable of handling high failure currents in both positive and negative directions, addressing the limitations of conventional stacked ESD devices.
Implementation Method 1
a plurality of field plates on the isolation structure, the plurality of field plates surround the plurality of wells of the first type
Implementation Method 2
an isolation structure surrounding the plurality of wells of the first type, the isolation structure isolating the well of the second type from the plurality of wells of the first type
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
The present disclosure relates to semiconductor structures and, more particularly, to silicon controlled rectifiers with field plate structures and methods of manufacture. The structure includes: a plurality of wells of a first type in a semiconductor substrate; a well of a second type in the semiconductor substrate, the well of the second type surrounding the plurality of wells of the first type; an isolation structure surrounding the plurality of wells of the first type, the isolation structure isolating the well of the second type from the plurality of wells of the first type; and a plurality of field plates on the isolation structure, the plurality of field plates surround the plurality of wells of the first type.