ZnON Thin Film Transistor Oxygen Plasma Treatment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

ZnON-based thin film transistors exhibit high turn-off current and significant negative shift in turn-on voltage, limiting their use in semiconductor displays due to suboptimal electrical characteristics.

Innovation Solution

Treating the ZnON active layer with a plasma comprising oxygen to increase oxygen content, thereby reducing carrier density and improving the on/off current ratio, which is achieved by patterning and plasma bombarding the active layer, followed by depositing and annealing the source-drain electrode layer to ensure even oxygen distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If ZnON is used as the active layer material, then the transistor can be manufactured with standard processes, but the turn-off current becomes excessively high and the turn-on voltage shifts negatively

Engineering Contradiction:
ImprovemanufacturabilityVSAvoidelectrical characteristics
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies plasma treatment to change the chemical composition parameters of the ZnON active layer by introducing oxygen. This modifies the material properties to reduce carrier density and improve electrical characteristics, specifically lowering turn-off current and reducing negative voltage shift while maintaining manufacturability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses oxygen plasma as a strong oxidizing environment to treat the ZnON active layer. This accelerated oxidation process increases oxygen content in the material, which passivates defects and reduces carrier density, thereby improving the electrical characteristics without requiring changes to the manufacturing process

Inventive Principle:
Principle #38Strong oxidants (Accelerated oxidation)

2Reliability

If the active layer is treated with oxygen plasma, then the turn-off current decreases and electrical characteristics improve, but the manufacturing process becomes more complex

Engineering Contradiction:
Improveelectrical characteristicsVSAvoidprocess complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs plasma treatment at a specific stage in the manufacturing process - after the active layer is formed but before source-drain electrode deposition. This preliminary action prepares the active layer with optimal electrical characteristics early in the process, preventing subsequent issues and reducing the need for additional corrective steps

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The oxygen plasma acts as an intermediary treatment between the active layer formation and source-drain deposition. It modifies the active layer properties without requiring direct contact with source-drain materials, serving as a bridge that improves electrical characteristics while maintaining process compatibility

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 method significantly reduces turn-off current and negative shift in turn-on voltage, resulting in a thin film transistor with enhanced electrical characteristics and improved display quality.

Implementation Method 1

treating the active layer with a plasma comprising oxygen

Methodology Applied
Scientific EffectPlasma: Plasma

Implementation Method 2

The active layer is treated with bombardment of a plasma comprising oxygen

Methodology Applied
Scientific EffectPlasma bombardment: Ion Beam

Implementation Method 3

annealing the base substrate having the deposited source-drain electrode layer

Methodology Applied
Scientific EffectAnnealing: Annealing

Data Source

PatentEP3295475B1Thin film transistor, array substrate and display device having the same, and method of manufacturing thereof
Publication Date: 2023.08.02 BOE TECHNOLOGY GROUP CO LTD
  • EP3295475B1 patent drawingFigure 1~2C
  • EP3295475B1 patent drawingFigure 2D~2F
  • EP3295475B1 patent drawingFigure 2G~2H

AI summary

The disclosure provides a method of manufacturing a thin film transistor on a base substrate by patterning an active layer comprising a metal oxynitride, and treating the active layer with a plasma comprising oxygen.