Nitride Semiconductor Device with Vacuum Recess for Field Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor devices with a nitride semiconductor layer, the electric field concentrates at the corners of the body region where the drift, JFET, and body regions intersect, leading to dielectric breakdown, which is not effectively suppressed by existing technologies.
Innovation Solution
A semiconductor device with a nitride semiconductor layer that includes a space in a vacuum state within the layer, corresponding to the region where the electric field concentrates, utilizing a high dielectric strength to prevent dielectric breakdown, and a manufacturing method that forms these spaces by exposing the drift, JFET, and body regions to the vacuum space during the bonding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional semiconductor structure with drift region, JFET region, and body region is used, then the device can achieve normal semiconductor operation, but electric field concentrates at the corner of the body region where three regions contact, causing dielectric breakdown
Solution Approach 1:
The patent extracts the problematic corner region where electric field concentrates by removing part of the body region to create a recess. This removes the harmful concentration point while maintaining the functional integrity of the drift, JFET, and body regions. The recess space eliminates the corner effect that causes dielectric breakdown.
Solution Approach 2:
The patent introduces a spatial dimension by creating a recess (void space) within the semiconductor layer. This dimensional change transforms the two-dimensional planar structure into a three-dimensional structure with a cavity, allowing the electric field to be redistributed and preventing concentration at the original corner point.
2Reliability
If insulator is placed to suppress dielectric breakdown, then breakdown voltage can be improved, but heat confinement issues occur and on-resistance increases
Solution Approach 1:
Instead of adding an insulator that would trap heat, the patent extracts material to create a void recess. This removes the problematic corner region without introducing additional material that could cause heat confinement. The recess provides breakdown suppression through geometric field redistribution rather than through insulating material.
Solution Approach 2:
The patent creates a porous or void structure (recess) within the semiconductor layer. This void space acts similarly to porous materials by providing pathways for field redistribution and avoiding the heat trapping associated with solid insulating materials. The empty space allows better thermal management compared to solid insulator placement.
3Reliability
If the body region is reduced to eliminate electric field concentration, then dielectric breakdown is suppressed, but the device area and potential current carrying capacity are reduced
Solution Approach 1:
The patent segments the body region by creating a recess that divides the originally continuous body region into separate portions. This segmentation removes the problematic corner area while preserving the functional body region areas that are needed for current conduction and device operation. The body region is divided but not completely reduced.
Solution Approach 2:
The patent applies local quality change by modifying only the specific corner region where electric field concentrates, while leaving the rest of the body region intact. The recess is localized to the problematic area, allowing the majority of the body region to maintain its original area and functionality for current carrying capacity.
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 semiconductor device effectively suppresses dielectric breakdown at the electric field concentration points, allowing for a desired breakdown voltage while maintaining low on-resistance and avoiding heat confinement issues associated with insulator placement.
Implementation Method 1
Since the space has high dielectric strength, dielectric breakdown at the portion where electric field concentrates can be suppressed
Data Source
AI summary
A semiconductor device may include a semiconductor layer; a source electrode disposed above one main surface of the semiconductor layer; a drain electrode disposed below another main surface of the semiconductor layer; and an insulation gate section. The semiconductor layer may include a drift region of a first conductivity type; a JFET region of the first conductivity type disposed above the drift region; a body region of a second conductivity type disposed above the drift region and adjoining the JFET region; and a source region of the first conductivity type separated from the JFET region by the body region. The insulation gate section may be opposed to a portion of the body region that separates the JFET region and the source region, a space may be provided within the semiconductor layer, and the drift region, the JFET region and the body region may be exposed to the space.