Semiconductor Contact and Defect Layer Structure for Injection Efficiency

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Solution Overview

Problem

Existing semiconductor devices face challenges in optimizing injection efficiency, particularly in power semiconductor devices handling high voltages and currents, where control over dopant doses is insufficient to achieve desired performance.

Innovation Solution

A semiconductor device structure comprising a contact layer with higher activated dopant concentration and a defect layer with lower activated dopant concentration, where the dopants are introduced through implantation and annealing processes to control amorphousness and injection efficiency, and a method for producing this structure involving multiple heating steps to optimize dopant placement and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If dopant doses are varied to control injection efficiency, then injection efficiency can be adjusted, but manufacturing precision and reliability are insufficient

Engineering Contradiction:
Improveinjection efficiencyVSAvoiddopant dose control
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The contact layer is divided into two distinct regions: a first region with higher activated dopant concentration and a second region with lower activated dopant concentration. This segmentation allows independent optimization of injection efficiency (first region) and manufacturing precision (second region), resolving the contradiction between adaptability and manufacturing precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the contact layer are assigned different dopant concentrations tailored to their specific functional requirements. The first region has higher dopant concentration for optimal injection efficiency, while the second region has lower dopant concentration for improved manufacturing precision and reliability, eliminating the need for uniform dopant dosing across the entire contact layer.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If single ion implantation processing step is used, then manufacturing process is simplified, but injection efficiency optimization is insufficient

Engineering Contradiction:
Improveprocessing stepsVSAvoidinjection efficiency
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

Dopants are introduced into the contact layer in advance through ion implantation, creating a dopant distribution profile that will yield the desired two-region structure after activation. This preliminary doping action, combined with selective annealing, enables precise control of injection efficiency while maintaining manufacturing simplicity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The dopant concentration profile is optimized by controlling annealing parameters (temperature, time, atmosphere) to achieve partial activation. This parameter control creates the distinctive two-region structure with different activated dopant concentrations, enabling injection efficiency optimization without adding complex processing steps.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If dopant concentration is increased to improve injection efficiency, then device performance improves, but device complexity increases

Engineering Contradiction:
Improvedevice efficiencyVSAvoiddopant distribution structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The contact layer is segmented into two regions with different dopant concentrations, where the first region has higher concentration for improved device efficiency and the second region has lower concentration to maintain manufacturability. This segmentation resolves the contradiction between productivity and device complexity by creating a structured yet manageable dopant distribution.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The contact layer functions as a composite structure with two distinct dopant concentration zones, combining the benefits of high-dopant regions (improved injection efficiency) and low-dopant regions (reduced complexity). This composite approach enables optimized device performance without proportionally increasing overall device complexity.

Inventive Principle:
Principle #40Composite materials

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 structure allows for pre-setting injection efficiency according to needs, improving performance in high-voltage and high-current applications by optimizing dopant distribution and crystal lattice amorphousness, thereby enhancing device efficiency and reliability.

Implementation Method 1

the semiconductor film is heated at least in regions such that a contact layer and a defect layer are generated

Methodology Applied
Scientific EffectAnnealing: Annealing

Implementation Method 2

at least some of the first dopants can move from interstitial lattice sites to substitutional lattice sites

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP4016647B1Structure for a semiconductor device and method for producing a structure for a semiconductor device
Publication Date: 2024.02.07 HITACHI ENERGY LTD
  • EP4016647B1 patent drawingFigure 1~2
  • EP4016647B1 patent drawingFigure 3~4
  • EP4016647B1 patent drawingFigure 5~6

AI summary

A structure (1) for a semiconductor device is provided, with - a contact layer (4) comprising first dopants of a first conductivity type, - a base layer (2) of a second conductivity type, and - a defect layer (5) comprising first dopants of the first conductivity type, wherein - a concentration of the first dopants being activated in the contact layer (4) is higher than a concentration of the first dopants being activated in the defect layer (5). Further, a method for producing a structure for a semiconductor device is provided.