High-Side Circuit Isolation Layout for Multi-Voltage HVICs

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Solution Overview

Problem

Conventional semiconductor devices with high-voltage integrated circuits (HVICs) face challenges in accommodating multiple high-side circuits operating at different power supply voltages within the high-side circuit region without increasing the device size.

Innovation Solution

The semiconductor device incorporates a high-side circuit region with first and second high-side circuit regions, each operating at distinct power supply voltages, and utilizes a second isolation region to electrically isolate these circuits, allowing for miniaturization without compromising performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple high-side circuits operating at different power supply voltages are provided in the high-side circuit region, then the device functionality and versatility are improved, but the device size increases

Engineering Contradiction:

Improveability to operate multiple high-side circuits at different voltagesVSAvoiddevice size

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The high-side circuit region is divided into multiple isolated regions (first high-side circuit region, second high-side circuit region, etc.) using isolation regions. Each region can independently host high-side circuits operating at different power supply voltages. This segmentation allows multiple circuits with different voltage requirements to coexist in a compact area without electrical interference, resolving the contradiction between versatility and device size.

Inventive Principle:

Principle #1Segmentation

2Reliability

If high breakdown voltage termination structure and level shift circuit are electrically isolated by trench isolation, then the breakdown voltage performance is improved, but the manufacturing complexity increases

Engineering Contradiction:

Improvebreakdown voltage performanceVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent combines multiple isolation functions into a single integrated isolation structure. The isolation regions serve both to electrically isolate the high breakdown voltage termination structure from the level shift circuit AND to separate multiple high-side circuit regions operating at different voltages. This merging of isolation functions maintains high breakdown voltage performance while reducing manufacturing complexity compared to implementing separate isolation structures for each function.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS20250120134A1Semiconductor device

Publication Date: 2025.04.10 MITSUBISHI ELECTRIC CORP

AI summary

In a semiconductor device, a first N-type diffusion layer is provided in a first high-side circuit region, and a second N-type diffusion layer is provided in a second high-side circuit region. Constituent elements for first and second high-side circuits are provided in the first and second N-type diffusion layers. An isolation trench is provided between the first N-type diffusion layer and the second N-type diffusion layer. The deepest portion of the isolation trench reaches a P-type substrate region of a P-type substrate. The first N-type diffusion layer and the second N-type diffusion layer are electrically isolated by the isolation trench having a buried insulating film inside.