Schottky Barrier Diode Guard Ring Insulating Layers
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Solution Overview
Problem
The reverse surge capacity of Schottky barrier diodes is not adequately improved in existing JBS structures due to field concentration issues, as the depletion layer extends from the schottky junction, limiting the reduction of voltage in p-type second semiconductor layers.
Innovation Solution
The implementation of a Schottky barrier diode with multiple insulating layers, including a second and third insulating layer made of semiconductor oxide, prevents the depletion layer from extending along the side surfaces of the second semiconductor layers, thereby reducing field concentration and increasing the reverse surge capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If p-type second semiconductor layers are disposed close to the schottky junction portion to reduce voltage, then the reverse surge capacity should be improved, but the depletion layer extends from the schottky junction along the second semiconductor layers, causing field concentration that prevents sufficient voltage reduction
Solution Approach 1:
An insulating layer is introduced as an intermediary between the schottky junction portion and the p-type second semiconductor layers. This insulating layer prevents the depletion layer from extending along the side surfaces of the second semiconductor layers, thereby blocking the field concentration effect while allowing the voltage reduction function to operate effectively. The insulating layer acts as a mediator that separates the electric field paths.
Solution Approach 2:
The space around the schottky junction is segmented by introducing the insulating layer that covers the side surfaces of the second semiconductor layers. This segmentation isolates the depletion layer extension path, confining it to specific regions and preventing it from propagating along the second semiconductor layers. The insulating layer creates distinct functional zones within the device structure.
2Strength
If the JBS structure is used to improve reverse surge capacity, then the diode can handle higher reverse voltages, but the depletion layer extension causes field concentration that limits the effectiveness of voltage reduction in second semiconductor layers
Solution Approach 1:
The insulating layer serves as a mediator that precisely controls the electric field distribution by blocking depletion layer extension. This allows for more precise control of the voltage characteristics in the second semiconductor layers, ensuring that the voltage reduction function operates at the designed level without being compromised by unwanted field concentration effects.
3Reliability
If multiple insulating layers are added to prevent depletion layer extension, then field concentration is reduced and reverse surge capacity is improved, but the device structure becomes more complex
Solution Approach 1:
The insulating layer is implemented as a thin film that covers the side surfaces of the second semiconductor layers. This thin film approach provides the necessary electrical isolation and field control functions without adding significant structural bulk or complexity. The thin film nature of the insulating layer allows it to be integrated into the existing device architecture with minimal additional manufacturing steps.
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 significantly enhances the reverse surge capacity by preventing depletion layer extension, concentrating the electric field on the second semiconductor layers and reducing the voltage, thus preventing diode breakdown under reverse voltage.
Implementation Method 1
a depletion layer extends from the schottky junction portion along the second semiconductor layers
Implementation Method 2
field concentration in the peripheral region is not actually reduced
Implementation Method 3
rectification behavior of schottky barrier caused by schottky junction between a semiconductor layer and a metal layer
Implementation Method 4
second semiconductor layers...which form p-n junction with the n-type semiconductor layer
Data Source
Figure 1A~1B
Figure 2
Figure 3~4
AI summary
A Schottky barrier diode comprising a guard ring layer (15) along the periphery region in which a first insulating layer (21) contacts the Schottky metal layer (14) and a plurality of second semiconductor layers (16) being arranged in a direction from the guard ring layer toward a center region of the substrate. A second (22) and a third (23) insulating layer are disposed respectively between the guard ring layer and the second semiconductor layer (16) which is closest to the guard ring layer and between two adjacent second semiconductor layers (16).