IGBT Diode Cell Defect Layer Protrusion for Loss Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor devices with IGBT and diode cells on the same substrate face challenges in reducing switching and recovery losses while maintaining low ON voltage, as the protrusion amount of the lattice defect layer into the IGBT cell affects the characteristics of the ON voltage and recovery loss.
Innovation Solution
A semiconductor device configuration where a first defect layer is created in the diode cell by ion irradiation, and a second defect layer extends into the IGBT cell, with a boundary region between the IGBT and diode cells, optimizing the area ratio SD1/S to minimize charge accumulation and reduce switching and recovery losses without increasing the ON voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a lattice defect layer is provided by ion irradiation to control lifetime in the diode cell, then switching loss and recovery loss can be reduced, but the ON voltage of the IGBT may deteriorate when the protrusion amount is large
Solution Approach 1:
The patent applies local quality by creating different defect layer configurations in different regions: a first defect layer in the diode cell and a second defect layer extending into the IGBT cell. This localized approach allows optimization of switching loss in the diode cell while controlling the protrusion into the IGBT cell to maintain acceptable ON voltage characteristics, rather than applying uniform ion irradiation across the entire device.
Solution Approach 2:
The patent employs parameter changes by precisely controlling the protrusion amount of the second defect layer into the IGBT cell within a specific range (0.1μm to 10μm). By adjusting this geometric parameter, the invention optimizes the balance between reducing recovery loss (which requires larger protrusion) and maintaining ON voltage characteristics (which deteriorate with excessive protrusion).
2Loss of energy
If the protrusion amount of the lattice defect layer into the IGBT cell is increased to reduce recovery loss, then switching loss decreases, but ON voltage characteristics may deteriorate
Solution Approach 1:
The patent applies parameter changes by establishing an optimal protrusion amount range (0.1μm to 10μm) for the second defect layer into the IGBT cell. Within this range, the invention achieves sufficient reduction in recovery loss while preventing excessive protrusion that would cause ON voltage deterioration. This quantitative parameter control resolves the contradiction between loss reduction and voltage maintenance.
Solution Approach 2:
The patent applies partial action by providing a second defect layer that extends only partially into the IGBT cell rather than across the entire IGBT region. This partial extension (limited to 0.1μm-10μm protrusion) is sufficient to reduce recovery loss through charge injection control, while avoiding excessive action that would significantly increase ON voltage and harm IGBT performance.
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 effectively reduces the sum of switching and recovery losses (Eon+Err) by controlling charge injection and maintaining a low ON voltage, eliminating the trade-off between ON voltage and recovery loss, and allows for a more efficient charge transfer path.
Implementation Method 1
a first defect layer disposed in the drift region of the diode cell as a lattice defect layer provided by ion irradiation
Data Source
AI summary
A semiconductor device includes a semiconductor substrate provided with an IGBT cell having a collector region and a diode cell having a cathode region, a first defect layer and a second defect layer in a drift region. A region present in the drift region and surrounded by an interface between the IGBT cell and the diode cell orthogonal to a first principal plane, and a plane passing through a boundary between the collector region and the cathode region on a boundary line along an interface between the collector region and the drift region and crossing the first principal plane at an angle of 45 degrees is referred to as a boundary region. The diode cell satisfies a relationship of SD1>S, in which S is an area occupied by the boundary region and SD1 is an area occupied by the diode cell in a surface of the drift region.