Flexible Semiconductor Devices Using Thermal Expansion Separation

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Solution Overview

Problem

Existing semiconductor devices based on nitride semiconductors are limited by their rigidity, high manufacturing costs, and difficulty in producing large-size devices with variable shapes, while maintaining high optoelectronic performance.

Innovation Solution

A flexible semiconductor device with a vertical semiconductor element having a core-shell structure, embedded in a flexible material layer with a buffer layer and electrodes, utilizing a difference in thermal expansion coefficients to separate the device from the substrate, allowing for low-cost, large-size, and shape-variable manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a monocrystalline nitride layer is epitaxially grown on a sapphire substrate or silicon substrate to manufacture light-emitting devices based on nitride semiconductors, then high efficiency and high luminance are achieved, but the device shape cannot be varied and manufacturing costs are high

Engineering Contradiction:
Improveoptoelectronic performanceVSAvoiddevice shape variability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies this principle by transferring the nitride semiconductor layer from a rigid sapphire substrate to a flexible polymer substrate (such as PET or PI). The semiconductor layer is formed as a thin film that can be bent and shaped, while maintaining its crystalline structure and optoelectronic properties. This allows the device to achieve variable shapes while preserving high efficiency and luminance.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent changes the substrate material parameter from rigid sapphire/silicon to flexible polymer, and changes the growth method from direct epitaxial growth on rigid substrates to a two-step process: epitaxial growth on a temporary substrate followed by transfer to the flexible substrate. This parameter change enables shape variability while maintaining optoelectronic performance.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a monocrystalline nitride layer is epitaxially grown on a sapphire substrate or silicon substrate to manufacture light-emitting devices based on nitride semiconductors, then high efficiency and high luminance are achieved, but manufacturing costs are high and large size device manufacturing is difficult

Engineering Contradiction:
Improveoptoelectronic performanceVSAvoidmanufacturing cost and scalability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By using flexible polymer substrates instead of expensive sapphire substrates, the patent reduces material costs. The flexible substrates are cheaper and allow for larger area coverage. The thin film transfer process enables scalable manufacturing of large-size devices that would be difficult and costly to produce using conventional rigid substrate methods.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent segments the manufacturing process into distinct steps: epitaxial growth on a temporary substrate, pattern formation, and transfer to the final flexible substrate. This segmentation allows for optimized processing at each stage and facilitates scalable production of large-area devices with consistent quality.

Inventive Principle:
Principle #1Segmentation

3Manufacturing precision

If conventional rigid substrate methods are used to manufacture semiconductor devices, then manufacturing precision is maintained, but the devices lack flexibility and cannot be bent or shaped

Engineering Contradiction:
Improveepitaxial growth qualityVSAvoiddevice flexibility
Core Design Contradiction:
Manufacturing precisionVSShape

Solution Approach 1:

The patent creates a thin film semiconductor structure on a flexible substrate that can be bent and shaped. The thin film nature of the semiconductor layer (grown epitaxially with high precision on a temporary substrate) allows it to conform to flexible substrates while maintaining its crystalline quality and manufacturing precision.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent uses a temporary substrate as an intermediary during manufacturing. The high-precision epitaxial growth is performed on the temporary substrate, then the semiconductor layer is transferred to the flexible substrate. This intermediary approach allows precise manufacturing to be decoupled from the final flexible form factor.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enables the production of flexible semiconductor devices with excellent optoelectronic characteristics, low manufacturing costs, and large surface areas, while preventing non-radiative recombination and simplifying the manufacturing process.

Implementation Method 1

utilizing a difference in thermal expansion coefficients to separate the device from the substrate

Methodology Applied
Scientific EffectThermal expansion coefficient difference: Thermal Expansion

Data Source

PatentEP2704216B1Flexible semiconductor devices and methods of manufacturing the same
Publication Date: 2018.06.13 SAMSUNG ELECTRONICS CO LTD
  • EP2704216B1 patent drawingFigure 1~2
  • EP2704216B1 patent drawingFigure 3~4
  • EP2704216B1 patent drawingFigure 5A~5B

AI summary

A flexible semiconductor device and a method of manufacturing the flexible semiconductor device are provided. The flexible semiconductor device may include at least one vertical semiconductor element that is at least partly embedded in a flexible material layer. The flexible semiconductor device may further include a first electrode formed on a first surface of the flexible material layer and a second electrode formed on a second surface of the flexible material layer. A method of manufacturing a flexible semiconductor device may include separating a flexible material layer, in which the at least one vertical semiconductor element is embedded, from a substrate by weakening or degrading an adhesive force between an underlayer and a buffer layer by using a difference in coefficients of thermal expansion of the underlayer and the buffer layer.