IGBT Cell Structure with Segmented Hole Collector Regions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing IE type trench gate IGBTs suffer from high on-voltage and large feedback capacity, leading to increased off-switching losses and low erroneous roll call tolerance due to the accumulation of positive holes on the surface side and high gate-collector feedback capacity.
Innovation Solution
The semiconductor device incorporates a unique structure with alternating linear active and hole collector cell regions, featuring narrower trench gate electrodes and a P-type floating region, which reduces the on-voltage and feedback capacity by enhancing positive hole accumulation and discharge, while maintaining a balanced carrier concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If positive holes are accumulated on the surface side to improve on-voltage capability, then on-voltage capability is improved, but feedback capacity increases leading to large off switching loss
Solution Approach 1:
The cell region is divided into multiple linear unit cell regions, each containing both active cell regions and hole collector cell regions. This segmentation allows positive holes to be discharged locally at multiple distributed contact parts rather than accumulating at a single contact part, reducing feedback capacity while maintaining on-voltage capability.
Solution Approach 2:
Hole collector cell regions are introduced as intermediary structures between active cell regions and contact parts. These hole collector cell regions provide additional discharge paths for positive holes through their respective contact parts, acting as intermediaries that reduce hole accumulation and feedback capacity while preserving the on-voltage characteristics.
2Loss of energy
If feedback capacity is reduced to decrease off switching loss, then off switching loss is reduced, but on-voltage capability deteriorates
Solution Approach 1:
By segmenting the cell region into multiple linear unit cell regions with distributed contact parts, the feedback capacity is reduced through decreased hole accumulation, while the on-voltage capability is maintained through the preserved active cell region functionality and controlled hole distribution.
Solution Approach 2:
Different regions within the cell structure are assigned different functions: active cell regions maintain on-voltage capability through controlled hole accumulation, while hole collector cell regions provide localized discharge paths. This local differentiation allows simultaneous optimization of both on-voltage capability and off switching loss.
3Area of stationary object
If chip area is reduced to improve integration, then manufacturing efficiency is improved, but manufacturing precision requirements increase
Solution Approach 1:
The cell region is divided into multiple linear unit cell regions that can be formed using standard photolithography patterns. This segmentation into repeatable units allows for precise manufacturing using conventional processes while achieving high integration density and reduced chip area.
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
This configuration achieves a decrease in on-voltage and feedback capacity, improving switching characteristics and erroneous roll call tolerance by effectively managing positive hole distribution and discharge.
Implementation Method 1
the accumulation effect of the positive holes is great on the surface side
Implementation Method 2
positive holes injected from the back surface electrode can be discharged
Data Source
AI summary
A linear active cell region is formed from a plurality of divided active cell regions arranged apart from each other in a second direction (y direction). The linear hole collector cell region is formed from a plurality of divided hole collector cell regions arranged apart from each other in the second direction (y direction). A P-type floating region is formed in a semiconductor substrate between the linear active cell region and the linear hole collector cell region adjacent to each other in a first direction (x direction), between the divided active cell regions adjacent to each other in the second direction (y direction), and between the divided hole collector cell regions adjacent to each other in the second direction (y direction).