Vertically Stacked Diode-Trigger SCR With Trap-Rich ESD Scaling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor structures, such as bulk string diodes, suffer from junction breakdown, poor voltage scaling, and harmonics distortion, particularly in high-power applications, and often provide lower electrostatic discharge (ESD) protection levels due to reliance on self-protection mechanisms.
Innovation Solution
A vertically stacked diode-trigger silicon controlled rectifier (SCR) is fabricated on a trap-rich semiconductor substrate, incorporating trigger diodes vertically integrated with the SCR, utilizing a polysilicon layer and gate dielectric material, which eliminates the Darlington effect, reduces capacitance, and minimizes harmonic distortion without additional masking steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bulk string diodes are used for ESD protection, then device simplicity is maintained, but junction breakdown occurs causing poor voltage scaling and harmonics distortion
Solution Approach 1:
The invention segments the protection function by integrating a trigger diode and SCR structure instead of using a single bulk diode. This segmentation allows the trigger diode to activate the SCR at a controlled voltage threshold, preventing uncontrolled junction breakdown and reducing harmonic distortion while maintaining ESD protection capability
Solution Approach 2:
The invention changes the voltage threshold parameter by using a trap-rich semiconductor substrate that enables precise control of the trigger voltage. The trap-rich region creates a well-defined breakdown voltage that improves voltage scaling and eliminates the poor voltage scaling associated with bulk diodes
2Reliability
If vertically stacked diode-trigger SCR structure is implemented, then ESD protection and voltage scaling are improved, but device complexity increases
Solution Approach 1:
The invention merges the trigger diode and SCR structures into a single vertically stacked integrated device. This combination achieves sophisticated ESD protection and voltage scaling functionality while maintaining a compact footprint and avoiding the need for separate discrete components, thus managing device complexity effectively
Solution Approach 2:
The invention transitions from a planar diode structure to a vertically stacked three-dimensional structure. This dimensional change allows multiple functional regions (trigger diode, trap-rich region, SCR) to be integrated in the vertical direction, achieving complex functionality without increasing lateral device area
3Reliability
If trigger diodes are vertically integrated with SCR, then capacitance is reduced, but manufacturing process complexity increases
Solution Approach 1:
The trap-rich semiconductor substrate provides self-service by naturally creating the desired low-capacitance environment through its inherent trap characteristics. The substrate automatically establishes the voltage threshold and capacitance properties without requiring additional complex manufacturing steps or external components
Data Source
AI summary
The present disclosure relates to semiconductor structures and, more particularly, to vertically stacked diode-trigger silicon controlled rectifiers and methods of manufacture. The structure includes: a silicon controlled rectifier in a trap rich region of a semiconductor substrate; and at least one diode built in polysilicon (gate material) and isolated by a gate-dielectric.