Termination Insulating Film Layout for Stable Breakdown Voltage

Solution Overview

Problem

Existing semiconductor devices with semi-insulating films in the termination region face issues with electron and hole trapping, leading to fluctuations in electric field distribution and breakdown voltage, particularly due to direct contact between the semi-insulating film and the semiconductor layer.

Innovation Solution

A semiconductor device configuration with a semi-insulating film and an insulating film sandwiched between the semi-insulating film and the semiconductor layer, featuring a thin intermediate portion to minimize electron and hole trapping, and a specific thickness ratio of insulating film layers to control depletion layers and electric field distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a semi-insulating film is directly contacted with the semiconductor layer in the termination region, then the device structure is simplified, but electron and hole trapping occurs leading to fluctuations in electric field distribution and breakdown voltage

Engineering Contradiction:

Improvestructure complexityVSAvoidelectric field distribution stability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

An insulating film is introduced as an intermediary layer between the semi-insulating film and the semiconductor layer in the termination region. This intermediate insulating film prevents direct contact between the semi-insulating film and the semiconductor layer, thereby eliminating electron and hole trapping while maintaining structural organization. The insulating film acts as a mediator that resolves the contradiction by preventing harmful interactions without significantly complicating the overall device structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If a semi-insulating film is directly contacted with the semiconductor layer in the termination region, then the manufacturing process is simplified, but breakdown voltage fluctuates due to charge trapping

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoidbreakdown voltage stability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

An insulating film is introduced as an intermediary layer between the semi-insulating film and the semiconductor layer in the termination region. This intermediate insulating film prevents direct contact between the semi-insulating film and the semiconductor layer, thereby eliminating electron and hole trapping while maintaining structural organization. The insulating film acts as a mediator that resolves the contradiction by preventing harmful interactions without significantly complicating the overall device structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If the insulating film has uniform thickness, then the manufacturing process is easier, but electron and hole trapping cannot be effectively minimized in critical regions

Engineering Contradiction:

Improveinsulating film deposition easeVSAvoidelectron and hole trapping reduction

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The insulating film is designed with non-uniform thickness, where the thickness varies depending on the location. Specifically, the insulating film has a greater thickness in regions where electron and hole trapping is most problematic. This local variation in thickness optimizes the prevention of charge trapping in critical areas while maintaining manufacturability, as the thickness gradient can be achieved through controlled deposition processes.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The solution moves from a uniform one-dimensional thickness parameter to a two-dimensional thickness distribution. By varying the thickness of the insulating film across different spatial locations, the design optimizes charge trapping prevention in specific regions without requiring complete uniformity throughout, thus balancing manufacturing ease with performance requirements.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS12543332B2Semiconductor device

Publication Date: 2026.02.03 KK TOSHIBA

AI summary

A semiconductor device includes a semiconductor layer including an element region, and a termination region; a first electrode; a second electrode; a semi-insulating film located on the termination region; an insulating film located between the semiconductor layer and the semi-insulating film; and a protective film located on the semi-insulating film. The insulating film includes an inner perimeter portion, the inner perimeter portion being located between an end portion of the first electrode positioned at the termination region side and an end portion of the second semiconductor part positioned at the termination region side, an outer perimeter portion located between the second electrode and the semiconductor layer, and an intermediate portion located between the inner perimeter portion and the outer perimeter portion. A thickness of the intermediate portion is less than a thickness of the inner perimeter portion and a thickness of the outer perimeter portion.