Rectifier Junction Structure for High Power Density in Small Chips

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Solution Overview

Problem

Conventional rectifier diodes suffer from low power output and require larger chip sizes to generate sufficient power, limiting their efficiency in high power applications.

Innovation Solution

A high power density rectifier apparatus is designed with a substrate silicon layer, a middle silicon layer, an upper silicon layer, and trench termination layers that increase the size of the p-n junction, allowing for higher power density while maintaining a smaller chip size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If conventional rectifier diode structure is used, then device simplicity is maintained, but power density is low

Engineering Contradiction:
Improvepower densityVSAvoiddevice structure
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The rectifier diode is segmented into multiple silicon layers (substrate layer, middle layer, upper layer) with distinct functions. The middle silicon layer is divided into multiple regions (first region, second region, third region) with different doping concentrations, allowing each segment to contribute differently to power density while managing electrical characteristics independently

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the middle silicon layer are doped with different concentrations of dopant atoms (first concentration in first region, second concentration in second region, third concentration in third region). This local variation in doping quality optimizes power density in specific areas while maintaining overall device functionality

Inventive Principle:
Principle #3Local quality

2Power

If larger chip size is used, then sufficient power output is achieved, but chip area increases

Engineering Contradiction:
Improvepower outputVSAvoidchip size
Core Design Contradiction:
PowerVSArea of stationary object

Solution Approach 1:

The patent transitions from a planar junction design to a three-dimensional stacked layer structure. By stacking multiple silicon layers vertically with intermediate contact structures, the effective junction area is increased without proportionally increasing the chip footprint, thereby achieving higher power output in a compact area

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The intermediate contact structure is nested within the layered silicon structure, with the contact extending through the middle silicon layer to connect upper and lower regions. This nested arrangement maximizes the use of vertical space within the chip, increasing power density without expanding the horizontal chip dimensions

Inventive Principle:
Principle #7Nested doll (Nesting)

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 solution achieves increased power density and efficiency by forming a larger p-n junction through novel geometry, enabling higher power output without the need for larger chip sizes.

Implementation Method 1

The device is manufactured using n-type and p-type semiconductor materials that are joined together via a junction. The p-n junction may be formed between the upper silicon layer and the middle silicon layer.

Methodology Applied
Scientific Effectp-n junction rectification: Diode

Data Source

PatentEP4379806A1High power density rectifier device
Publication Date: 2024.06.05 LITTELFUSE SEMICON WUXI
  • EP4379806A1 patent drawingFigure 1a~1c
  • EP4379806A1 patent drawingFigure 2a
  • EP4379806A1 patent drawingFigure 2b

AI summary

A high power density rectifier diode apparatus, structure and associated methods thereof. The apparatus includes a substrate silicon layer, a middle silicon layer coupled to the substrate layer, an upper silicon layer coupled to the middle silicon layer, a cathode terminal coupled to the substrate silicon layer, an anode terminal coupled to the upper silicon layer, and one or more trench termination layers formed in the substrate silicon layer and at least a portion of the middle silicon layer. The trench termination layers are configured to be formed on at least one side of the substrate silicon layer and at least a portion of the middle silicon layer. The substrate silicon layer is at least one of the following: an n-type layer, a p-type layer, and any combination thereof.