Semiconductor Device Segmented Anode for Recovery Speed
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Solution Overview
Problem
Conventional free-wheeling diodes (FWDs) used in power conversion devices, such as inverters, face challenges in widening the safe operation area during recovery while shortening recovery time, and reducing current and voltage oscillations, which are critical for improving the overall performance of these devices.
Innovation Solution
A semiconductor device with a p-intrinsic-n (PIN) diode structure is designed, featuring a high concentration p+-type semiconductor region and a low concentration p-type semiconductor region, along with an insulating layer, to enhance the breakdown resistance and recovery speed by dispersing avalanche current and suppressing hole injection from the anode side.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional FWD structure is used, then device simplicity is maintained, but safe operation area during recovery cannot be widened and recovery time cannot be shortened
Solution Approach 1:
The anode-side semiconductor region is segmented into multiple regions with different impurity concentrations (first concentration type and second concentration type), allowing different portions to perform different functions: one region suppresses hole injection while another disperses avalanche current, thereby widening the safe operation area without requiring a completely new device structure
Solution Approach 2:
Different regions within the anode-side semiconductor structure are assigned different impurity concentrations to create local variations in electrical properties. The low-concentration region specifically targets hole injection suppression at the anode interface, while the high-concentration region handles avalanche current dispersion, enabling localized optimization of recovery characteristics
2Productivity
If conventional FWD structure is used, then manufacturing simplicity is maintained, but recovery time cannot be shortened
Solution Approach 1:
The semiconductor structure is divided into regions with different impurity concentrations that can be formed through sequential doping processes. The first anode-side region (lower concentration) and second anode-side region (higher concentration) are created using standard doping techniques, allowing recovery time reduction without requiring exotic manufacturing methods
Solution Approach 2:
The impurity concentration parameter is varied across different regions of the anode-side semiconductor structure. By controlling the doping concentration levels and distributions during manufacturing, the recovery time is reduced through optimized charge carrier dynamics while using conventional semiconductor fabrication parameters
3Stability of the object's composition
If conventional FWD structure is used, then device simplicity is maintained, but current and voltage oscillation during recovery cannot be reduced
Solution Approach 1:
The second anode-side semiconductor region with higher impurity concentration is strategically positioned to handle avalanche current dispersion. This localized high-concentration region acts as a current distribution zone that prevents current concentration and reduces voltage oscillation during recovery, improving stability without complicating the overall device structure
Solution Approach 2:
The avalanche effect, which can cause harmful current concentration and voltage oscillation, is converted into a beneficial current dispersal mechanism. The high-concentration anode-side region is designed to intentionally induce and control avalanche breakdown, transforming the potentially harmful effect into a useful current distribution mechanism that reduces oscillation
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 enlarges the safe operation area during recovery, speeds up the recovery process, and increases breakdown resistance by dispersing avalanche current and reducing hole injection, thereby improving the performance of power conversion devices.
Implementation Method 1
dispersing avalanche current and suppressing hole injection
Implementation Method 2
suppressing hole injection from the anode side
Data Source
AI summary
According to one embodiment, a semiconductor device includes a first electrode, a second electrode, a first semiconductor layer, a first semiconductor region, a second semiconductor region, and an insulating layer. The first semiconductor layer is provided between the first electrode and the second electrode, and contacts the first electrode. The first semiconductor region is provided between the first semiconductor layer and the second electrode, and contacts the second electrode. The second semiconductor region is provided between the first semiconductor region and the second electrode, and contacts the second electrode. An impurity concentration of the second semiconductor region is higher than an impurity concentration of the first semiconductor region. An insulating layer has one end contacting the second electrode and the other end positioned in the first semiconductor layer. The insulating layer extends along the second electrode in a first direction from the first electrode towards the second electrode.