Gallium Oxide Schottky Junction Layout for Breakdown Suppression
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Solution Overview
Problem
Dielectric breakdown is likely to occur in semiconductor devices with n-type gallium oxide semiconductor layers and electrode layers forming Schottky junctions due to the concentration of electric fields on the outer peripheral end portion of p-type nickel oxide semiconductor layers, as it is difficult to reduce the acceptor density of these layers.
Innovation Solution
The semiconductor device incorporates a n-type gallium oxide semiconductor layer with a center region and a peripheral region having different donor densities, where the peripheral region has a lower donor density, and includes a first p-type nickel oxide semiconductor layer positioned between the n-type gallium oxide semiconductor layer and the electrode layer, with a specific thickness ratio and potential additional second p-type nickel oxide semiconductor layers in trench structures, to suppress electric field concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a p-type nickel oxide semiconductor layer is used as a peripheral withstand voltage structure in a Schottky junction device, then the device can provide voltage blocking capability, but electric field concentration occurs at the outer peripheral end portion leading to dielectric breakdown
Solution Approach 1:
The patent applies local quality by creating a non-uniform donor density distribution within the n-type gallium oxide semiconductor layer. The peripheral region has a lower donor density (5.0×10^15 cm^-3 or lower) compared to the center region (1.0×10^16 cm^-3 or higher). This spatial variation in electrical properties allows the peripheral region to act as an electric field relaxation zone, reducing field concentration at the outer peripheral end portion while maintaining the voltage blocking capability of the p-type nickel oxide semiconductor layer.
2Object-affected harmful factors
If the acceptor density of the p-type nickel oxide semiconductor layer is reduced to improve electric field distribution, then dielectric breakdown is suppressed, but it becomes difficult to achieve sufficient voltage blocking capability
Solution Approach 1:
The patent changes the donor density parameter of the n-type gallium oxide semiconductor layer to resolve the contradiction. By reducing the donor density in the peripheral region to 5.0×10^15 cm^-3 or lower (while keeping the center region at 1.0×10^16 cm^-3 or higher), the patent creates a gradient that naturally relaxes electric fields without requiring changes to the acceptor density of the p-type nickel oxide semiconductor layer. This parameter change enables both dielectric breakdown suppression and maintained voltage blocking capability.
3Reliability
If the first p-type nickel oxide semiconductor layer is positioned to straddle the center and peripheral regions, then electric field distribution is optimized, but the device structure becomes more complex
Solution Approach 1:
The patent applies segmentation by dividing the n-type gallium oxide semiconductor layer into distinct center and peripheral regions with different donor densities. The first p-type nickel oxide semiconductor layer is positioned to straddle these regions, with its outer peripheral end portion located in the peripheral region. This segmentation approach simplifies the overall structure compared to creating multiple separate layers, as it utilizes a single continuous p-type layer that benefits from the underlying donor density gradient.
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 suppresses dielectric breakdown, achieving a high withstand voltage property while maintaining resistivity, with withstand voltages exceeding 1200 V and resistivity comparable to baseline levels.
Implementation Method 1
an n-type gallium oxide semiconductor layer and an electrode layer form Schottky junction
Implementation Method 2
an electric field is concentrated on an outer peripheral end portion of the p-type nickel oxide semiconductor layer in contact with the electrode layer
Data Source
AI summary
The present disclosure relates to a semiconductor device including an n-type gallium oxide semiconductor layer that has a center region and a peripheral region having a lower donor density than the center region, an electrode layer that is laminated on the n-type gallium oxide semiconductor layer, and forms Schottky junction with the n-type gallium oxide semiconductor layer in the center region as viewed from a lamination direction, and a first p-type nickel oxide semiconductor layer that is laminated on the n-type gallium oxide semiconductor layer such that the first p-type nickel oxide semiconductor layer is partially positioned between the n-type gallium oxide semiconductor layer and the electrode layer, and has an outer peripheral end portion on a peripheral region side in the peripheral region as viewed from the lamination direction.