Multi-Collector ESD Protection Structure for Stable Holding Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor integrated circuits are vulnerable to physical damage from electrostatic discharge pulses due to their sensitivity to high voltages and currents, and existing electrostatic discharge protection devices struggle to effectively manage these risks as semiconductor device sizes decrease, reducing their voltage withstand capability.
Innovation Solution
An electrostatic discharge protection device is designed with specific conductivity-type regions and impurity concentrations on a semiconductor substrate, including emitter, base, collector, and well regions, along with isolation portions, to create a multi-collector structure that disperses current and secures a stable, high ESD current by operating as a multi-lateral bipolar junction transistor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If semiconductor device size is reduced, then integration density is improved, but voltage withstand capability deteriorates
Solution Approach 1:
The patent divides the collector region into multiple segments (first collector region, second collector region, third collector region) with different impurity concentrations and depths. This segmentation allows each region to handle different portions of the ESD current, enabling the device to maintain high voltage withstand capability despite reduced overall device size.
Solution Approach 2:
Different regions of the collector are assigned different local qualities through varying impurity concentrations (first, second, and third concentrations) and depths. The first collector region has higher impurity concentration for current collection, while the second and third regions have lower concentrations for voltage withstanding, optimizing both size and protection capability.
2Reliability
If multi-collector structure is implemented, then ESD current stability is improved, but device complexity increases
Solution Approach 1:
The collector is segmented into three distinct regions with different impurity concentrations and depths, allowing each segment to contribute differently to ESD current handling. This segmentation provides multiple current paths that stabilize the ESD response while maintaining a relatively compact structure.
Solution Approach 2:
The patent combines multiple collector regions into a unified lateral BJT structure that operates together to provide stable ESD protection. The merged structure shares common base and emitter regions, reducing overall complexity compared to separate protection devices while maintaining reliability through multiple current paths.
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 device achieves a high and stable electrostatic discharge current while maintaining a high holding voltage, ensuring effective protection against electrostatic discharge pulses and enabling a linear ESD current characteristic even in multi-array structures.
Implementation Method 1
The electrostatic discharge protection device serves to quickly remove the electrostatic discharge pulse having a high voltage and a high current when applied to the semiconductor device
Data Source
AI summary
An electrostatic discharge protection device includes: an emitter region disposed on a semiconductor substrate; a base region surrounding the emitter region; a first collector region surrounding the base region; a second collector region surrounding the first collector region; a second conductivity-type drift region below the emitter region, and being deeper than the base region; a second conductivity-type well region disposed below the base region, and having a junction interface with the second conductivity-type drift region; and a plurality of isolation portions disposed between the emitter region, the base region, and the first collector region and the second collector region.