Dielectric-Modified Diode Junctions for Lower Reverse Recovery Charge
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Solution Overview
Problem
Current semiconductor devices face challenges in reducing reverse recovery charge (Qrr) without compromising other performance parameters, often requiring significant changes in device architecture and processing operations.
Innovation Solution
The approach involves reducing the diode junction area of built-in diodes in semiconductor devices by partially filling portions of the P-N junction with dielectric regions, which can be precisely controlled through layout design, allowing for accurate reduction of Qrr without altering the basic device structure or doping profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the diode junction area is reduced to decrease reverse recovery charge, then reverse recovery charge is reduced, but the breakdown voltage and switching time may be compromised
Solution Approach 1:
The patent applies local quality by introducing dielectric regions at specific locations within the semiconductor device structure. These dielectric regions are positioned to modify the electric field distribution locally at the diode junction, allowing the junction area to be reduced for lower reverse recovery charge while the dielectric regions maintain the necessary electric field characteristics for adequate breakdown voltage. This localized modification enables independent optimization of different performance parameters in different spatial regions.
Solution Approach 2:
The patent employs parameter changes by modifying the physical and electrical parameters of the semiconductor structure through dielectric insertion. The dielectric regions change the permittivity distribution, which alters the electric field profile and charge distribution in the depletion region. This parameter modification allows the device to achieve reduced reverse recovery charge while maintaining breakdown voltage characteristics through controlled changes in the electric field parameters rather than simply scaling down the junction area.
2Loss of energy
If significant changes are made in device architecture and processing operations to reduce reverse recovery charge, then reverse recovery charge is reduced, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent applies segmentation by dividing the semiconductor device structure into distinct regions with different dielectric properties. Rather than fundamentally redesigning the entire device architecture, the invention segments the structure by inserting dielectric regions at specific locations, creating a modular approach that reduces reverse recovery charge through localized structural modifications while preserving the overall device architecture and processing compatibility.
3Loss of energy
If the diode junction area is reduced to reduce reverse recovery charge, then reverse recovery charge is reduced, but leakage current may increase
Solution Approach 1:
The patent employs the intermediary principle by introducing dielectric regions as intermediary elements between the P-type and N-type semiconductor regions. These dielectric regions act as mediators that modify the electric field distribution and charge carrier behavior at the junction interface. The dielectric intermediaries enable the reduced junction area to achieve lower reverse recovery charge while the dielectric properties maintain adequate barrier characteristics to prevent excessive leakage current.
Data Source
AI summary
In a general aspect, a method can include forming well region of one conductivity type in a semiconductor region of another conductivity type An interface between the well region and the semiconductor region can define a diode junction at a depth below an upper surface of the semiconductor region. The method can further include forming at least one dielectric region in the semiconductor region. A dielectric region of the at least one dielectric region can have an upper surface that is disposed in the well region at a depth in the semiconductor region that is above the depth of the diode junction; and a lower surface that is disposed in the semiconductor region at a depth in the semiconductor region that is the same depth as the diode junction or below the depth of the diode junction.