Laser Crystallization of Metal Oxide Semiconductor Layers

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Solution Overview

Problem

The existing methods for manufacturing thin film transistors (TFTs) using the back channel etch (BCE) process expose the active layer to etchants, leading to reduced yield due to corrosion vulnerability.

Innovation Solution

A method involving the crystallization of a metal oxide semiconductor layer using a heated amorphous silicon layer as a heat source, where an amorphous metal oxide semiconductor layer is converted into a crystallized form by irradiating an amorphous silicon layer with a laser, resulting in a corrosion-resistant structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the back channel etch (BCE) process is used to manufacture TFTs, then the manufacturing process becomes simpler and faster, but the active layer becomes vulnerable to etchant corrosion, reducing yield

Engineering Contradiction:

Improvemanufacturing speedVSAvoidyield

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The invention changes the physical state of the metal oxide semiconductor layer from amorphous to crystalline through laser irradiation heating. This parameter change (crystallization) fundamentally alters the material's properties, making it resistant to etchant corrosion while maintaining the simplicity of the BCE process

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention performs preliminary crystallization of the metal oxide semiconductor layer before the etching process. By pre-heating the layer to form crystals, the material gains etch resistance in advance, protecting it during subsequent etching operations and ensuring high yield

Inventive Principle:

Principle #10Preliminary action

2Ease of manufacture

If the amorphous metal oxide semiconductor layer is directly etched, then the process is simple, but the active layer is highly vulnerable to etchant corrosion

Engineering Contradiction:

Improveprocess simplicityVSAvoidetchant corrosion

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention uses laser irradiation, which initially seems like an additional complex step, to convert the amorphous layer into a crystalline structure. This transformation turns a potential weakness (amorphous structure vulnerability) into a strength (crystalline structure resistance), protecting the layer during etching

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 method effectively forms a crystallized metal oxide semiconductor layer with improved etch resistance to acidic etchants, enhancing the yield and stability of TFTs.

Implementation Method 1

irradiating the amorphous silicon layer by using a laser, so as to heat the amorphous silicon layer

Methodology Applied

Scientific EffectLaser heating: Laser

Implementation Method 2

the heated amorphous silicon layer heats the amorphous metal oxide semiconductor layer

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

the amorphous metal oxide semiconductor layer is converted into a crystallized metal oxide semiconductor layer

Methodology Applied

Scientific EffectCrystallization: Crystallisation

Data Source

PatentUS10566357B2Method for crystallizing metal oxide semiconductor layer, semiconductor structure, active array substrate, and indium gallium zinc oxide crystal

Publication Date: 2020.02.18 AU OPTRONICS CORP

AI summary

The present invention provides a method for crystallizing a metal oxide semiconductor layer, a semiconductor structure, a method for manufacturing a semiconductor structure, an active array substrate, and an indium gallium zinc oxide crystal. The crystallization method includes the following steps: forming an amorphous metal oxide semiconductor layer on a substrate; forming an oxide layer on the amorphous metal oxide semiconductor layer; forming an amorphous silicon layer on the oxide layer; and irradiating the amorphous silicon layer by using a laser, so as to heat the amorphous silicon layer, where the heated amorphous silicon layer heats the amorphous metal oxide semiconductor layer, so that the amorphous metal oxide semiconductor layer is converted into a crystallized metal oxide semiconductor layer.