Semiconductor Guard Ring Design for High Voltage Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing guard rings in semiconductor devices fail to sustain high voltage and stability, particularly under 700V in high temperature reverse bias reliability tests, necessitating a solution for improved voltage sustainability and stability without increasing device size.
Innovation Solution
A high-voltage-side semiconductor device design featuring a substrate with specific regions such as deep well, drain, gate, well, source, body contact, and annular doped regions, along with isolation structures, which allows for effective voltage reduction and integration of bootstrap diode functions by configuring the device into off-state for high voltage sustainability and on-state for bootstrap diode operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing guard ring structures are used, then device size is maintained, but voltage sustainability and stability deteriorate (fail to sustain 700V in HTRB test)
Solution Approach 1:
The guard ring is divided into multiple doped regions (first doped region, second doped region, third doped region) with different doping types and concentrations. This segmentation allows each region to perform specific functions: the first doped region provides isolation, the second doped region reduces voltage, and the third doped region enhances stability, collectively achieving 700V sustainability without increasing overall device complexity
Solution Approach 2:
Different doped regions are assigned different doping types (n-type, p-type) and concentrations tailored to their specific locations and functions within the guard ring structure. This local quality optimization ensures that each region contributes maximally to the overall voltage sustainability and stability while maintaining compact device dimensions
2Reliability
If guard ring structure is simplified, then device complexity is reduced, but voltage sustainability deteriorates (cannot sustain high voltage in HTRB test)
Solution Approach 1:
Multiple doped regions with different functions are merged into a single integrated guard ring structure. The first doped region (isolation), second doped region (voltage reduction), and third doped region (stability enhancement) are combined in close proximity, allowing the guard ring to achieve 700V sustainability through synergistic operation of all regions without requiring separate discrete components
Solution Approach 2:
The guard ring structure is designed to perform multiple functions simultaneously: isolation of high-voltage regions, voltage reduction through distributed resistance, and stability enhancement through complementary doped regions. This multi-functionality allows a single guard ring structure to address multiple reliability concerns without proportionally increasing device complexity
3Reliability
If device size is increased, then voltage sustainability may be improved, but device miniaturization is compromised
Solution Approach 1:
The multiple doped regions are nested within each other in a concentric or layered arrangement within the guard ring structure. The first, second, and third doped regions are positioned such that they occupy overlapping or adjacent spatial zones, maximizing the functional density and voltage sustainability capability within a compact footprint that does not increase overall device volume
Data Source
AI summary
A semiconductor device includes a substrate; a deep well region disposed in the substrate; an element region disposed in the substrate and in the deep well region; a drain region disposed in the substrate, in the deep well region, and surrounding the element region; a gate structure disposed on the surface of the substrate, adjacent to the deep well region, and surrounding the drain region; a well region disposed in the substrate, in the deep well region, and surrounding the gate structure; a source region disposed in the substrate, in the well region, and surrounding the gate structure; a body contact region disposed separately from the source region in the well region and surrounding the source region; and an annular doped region disposed separately from the deep well region in the substrate and surrounding the deep well region.