ESD Protection Structure Using Segmented Semiconductor Substrate
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Solution Overview
Problem
Existing ESD protective structures for semiconductor components face challenges in achieving high-performance ESD protection up to 15 kV without distorting signal waveforms, due to complex structures, inaccuracies in high substrate thickness, and increased resistance, which complicates production and affects performance.
Innovation Solution
A method involving a semiconductor substrate with a thin epitaxial semiconductor layer, buried layers, and dopant zones to form a PIN/NIP diode structure with reduced thickness, minimizing capacitance and resistance, while maintaining effective ESD protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high substrate thickness is used for the diode arrangement, then ESD protection capability is improved, but manufacturing precision deteriorates due to dopant diffusion through the complete substrate thickness
Solution Approach 1:
The substrate is segmented into multiple layers with different doping characteristics. A first substrate layer with first conductivity type and a second substrate layer with second conductivity type are combined, allowing the ESD protective structure to be divided into multiple functional regions. This segmentation enables precise control of dopant diffusion in each layer while maintaining overall ESD protection capability up to 15 kV.
2Reliability
If high substrate thickness is used for the diode arrangement, then ESD protection capability is improved, but device complexity increases due to lateral outdiffusion
Solution Approach 1:
Different regions of the substrate are assigned different doping types and concentrations to create localized functional zones. The first substrate layer has doping of a first conductivity type while the second substrate layer has doping of a second conductivity type. This local quality differentiation allows the structure to achieve complex ESD protection functions without requiring uniformly thick substrates, thereby reducing overall structural 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 method enables cost-effective production of high-performance ESD protective structures with reduced thickness, lowering clamping voltage and improving performance by minimizing capacitance and resistance, thus effectively protecting semiconductor components from high-speed data transmission without signal distortion.
Implementation Method 1
The dopant diffusion through the complete substrate thickness leads to inaccuracies and a high space requirement owing to the lateral outdiffusion that likewise takes place.
Data Source
AI summary
Described herein is a protective structure. The protective structure includes a semiconductor substrate, a first diode disposed at least one of in or on the semiconductor substrate and a diode arrangement disposed at least one of in or on the semiconductor substrate. The diode arrangement includes a stack of a second diode and a transient voltage suppressor (TVS) diode connected in series with the second diode. The diode arrangement is in parallel with the first diode.