Semiconductor Electrode Barrier Layer for Ion Diffusion Blocking
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Solution Overview
Problem
Semiconductor devices, such as insulated gate bipolar transistors (IGBTs), face challenges in maintaining high dielectric strength and breakdown voltage due to the diffusion of external ions through the passivation film, which can lead to reduced performance and reliability, especially in applications like vehicle inverter devices.
Innovation Solution
A semiconductor device structure incorporating a barrier layer with a smaller diffusion coefficient, such as silicon nitride, is used to limit the passage of external ions, combined with a passivation film having a larger diffusion coefficient, and a stepped barrier layer configuration to minimize cracking and ion charging, thereby enhancing dielectric strength and breakdown voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a passivation film is formed on the electrode to protect it, then the electrode is protected from environmental damage, but external ions can diffuse through the passivation film and reduce dielectric strength and breakdown voltage
Solution Approach 1:
A barrier layer is introduced as an intermediary between the passivation film and the electrode. This barrier layer has a smaller diffusion coefficient than the passivation film, effectively blocking external ions from reaching the electrode while maintaining the protective function of the passivation film structure.
Solution Approach 2:
The protective structure is formed as a composite of two different materials: a passivation film with larger diffusion coefficient for protection, and a barrier layer with smaller diffusion coefficient to block ion diffusion. This composite structure combines the advantages of both materials to simultaneously achieve protection and ion blocking.
2Object-affected harmful factors
If the passivation film is made thinner to reduce ion diffusion path, then ion diffusion is reduced, but the protective function and dielectric strength are compromised
Solution Approach 1:
The protective function is segmented into two distinct layers: the passivation film provides the primary protective function, while the barrier layer provides the ion diffusion blocking function. This segmentation allows each layer to be optimized for its specific function without compromising the other.
Solution Approach 2:
The barrier layer acts as an intermediary that specifically addresses the ion diffusion problem without affecting the protective function of the passivation film. The barrier layer's primary role is to block ion diffusion while the passivation film maintains the protective function.
3Object-affected harmful factors
If a uniform barrier layer is used to block ion diffusion, then ion diffusion is limited, but cracking and ion charging occur reducing effectiveness
Solution Approach 1:
The barrier layer is divided into multiple regions with different impurity concentrations. The first barrier layer region has a first impurity concentration while the second barrier layer region has a second impurity concentration different from the first. This local variation in quality reduces internal stress and prevents cracking while maintaining ion diffusion blocking capability.
Solution Approach 2:
The impurity concentration parameter is changed across different regions of the barrier layer. By varying the impurity concentration between the first and second barrier layer regions, the structural stability is improved, reducing cracking and ion charging while maintaining the ion diffusion blocking function.
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 solution effectively limits the diffusion of external ions, preventing a decrease in dielectric strength and maintaining high breakdown voltage, thus improving the reliability and performance of semiconductor devices in harsh environments.
Implementation Method 1
a barrier layer having a smaller diffusion coefficient than the passivation film
Data Source
AI summary
A semiconductor device comprises: a cell region and a peripheral region. The cell region includes an insulation film covering cells, and an electrode portion including a stacked part stacked on the insulation film. The peripheral region includes a first semiconductor layer of a first conductive type, a second semiconductor region of a second conductivity type, a peripheral insulation film, a peripheral electrode portion, a barrier layer, and a passivation film. The barrier layer covers both the peripheral insulation film and the peripheral electrode portion and has a smaller diffusion coefficient than the peripheral insulation film. The passivation film stacks on the barrier layer and has a larger diffusion coefficient than the barrier layer. The peripheral electrode portion includes a projection. A thickness of the projection is less than a thickness of the stacked part.