Vertical Transistor Discharging Region for Charge Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Vertical field-effect controlled transistor devices face challenges in efficiently removing charge carriers of the second conductivity type from the inactive region when transitioning from a bipolar conducting state to the off-state, which affects their ability to block voltage between the drain and source regions.
Innovation Solution
Incorporating a discharging region of the second doping type in the semiconductor body, located below the gate conductor, with at least one lower dose section associated with the corner of the gate conductor, to facilitate the flow of second type charge carriers from the inactive region to the active region, thereby reducing the time required to remove these carriers and prevent avalanche breakdown.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a discharging region is added to remove charge carriers from the inactive region, then the transistor device can block voltage more efficiently, but the device complexity increases
Solution Approach 1:
The discharging region is segmented into multiple sections with different doping doses. The first section has a first doping dose and the second section has a second doping dose that is different from the first. This segmentation allows optimized charge carrier removal in different areas while maintaining manageable structural complexity.
Solution Approach 2:
Different sections of the discharging region are assigned different doping doses according to their specific functional requirements. The first section and second section have different doping characteristics tailored to their respective roles in charge carrier removal, achieving local optimization without overwhelming overall complexity.
2Speed
If the discharging region uses high doping dose to remove charge carriers quickly, then the charge carrier removal speed increases, but high current densities may cause avalanche breakdown
Solution Approach 1:
The discharging region is divided into sections with different doping doses. The first section has a first doping dose and the second section has a second doping dose, allowing different areas to have different charge carrier removal rates. This local differentiation enables fast removal where needed while maintaining lower current densities in other areas to prevent avalanche breakdown.
Solution Approach 2:
By segmenting the discharging region into multiple sections with different doping characteristics, the patent distributes the charge carrier removal function across different areas. This segmentation prevents concentration of excessive current density in a single region, thereby reducing avalanche breakdown risk while maintaining effective charge carrier removal speed.
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 discharging region effectively supports the flow of charge carriers, reducing the time to completely remove charge carriers and enabling the transistor device to block voltage efficiently, while minimizing high current densities and avalanche breakdown risks.
Implementation Method 1
the discharging region facilitates the flow of second type charge carriers from the inactive region to the active region
Implementation Method 2
a discharging region of the second doping type arranged in the semiconductor body in the second region
Data Source
AI summary
A transistor device includes transistor cells each having source and drift regions of a first doping type and a body region of a second doping type in a first region of a semiconductor body, and a gate electrode dielectrically insulated from the body region. A gate conductor arranged on top of a second region of the semiconductor body is electrically connected to each gate electrode. A source conductor arranged on top of the first region is connected to each source and body region. A discharging region of the second doping type is arranged in the second region and located at least partially below the gate conductor, and includes at least one lower dose section in which a doping dose is lower than a minimum doping dose in other sections of the discharging region. The at least one lower dose section is associated with a corner of the gate conductor.