Amorphous TeOx TFT Channel for Stable P-Type Hole Transport

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Solution Overview

Problem

Current metal oxide semiconductors lack stable and high-performance p-type characteristics for hole transport at room temperature, limiting their application in optoelectronics and CMOS circuits.

Innovation Solution

The development of an amorphous p-type semiconductor using a tellurium oxide (TeOx) layer deposited via thermal evaporation or sputtering, with a chalcogen atom like sulfur or selenium doped into the tellurium composite, to enhance hole conduction and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional metal oxide semiconductors (e.g., Cu x O, SnO) are used to achieve p-type characteristics, then hole transport is possible at room temperature, but electrical performance deteriorates with low hole field-effect mobility and low on/off current ratio

Engineering Contradiction:
Improvep-type characteristics stabilityVSAvoidhole field-effect mobility
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the chemical composition parameters by introducing tellurium oxide (TeOx) with specific oxygen deficiency (x<2) and doping with chalcogen elements (S, Se, Te) at controlled concentrations (0.1-10 atom%). This parameter optimization resolves the contradiction by achieving both stable p-type characteristics and high hole mobility simultaneously, with reported hole field-effect mobility exceeding 10 cm²/Vs and on/off current ratio >10⁶.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite semiconductor material by combining tellurium oxide with chalcogen elements (forming TeOx:S, TeOx:Se, or TeOx:Te composites). This composite approach enables synergistic effects where the TeOx matrix provides stable p-type characteristics while chalcogen doping enhances carrier mobility, successfully resolving the performance limitation of conventional p-type metal oxides.

Inventive Principle:
Principle #40Composite materials

2Productivity

If n-type metal oxide semiconductors (e.g., a-InGaZnO) are used to achieve high electron transport performance, then excellent electron mobility is obtained, but p-type characteristics cannot be exhibited at room temperature

Engineering Contradiction:
Improveelectron transport efficiencyVSAvoidp-type characteristics
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

Instead of attempting to induce p-type characteristics in conventional metal oxides with limited success, the patent inverts the approach by selecting tellurium oxide as the base material and optimizing its oxygen deficiency and chalcogen doping. This inversion strategy achieves stable p-type characteristics with high hole mobility, effectively reversing the traditional n-type dominance in metal oxide semiconductors.

Inventive Principle:
Principle #13The other way round (Inversion)

3Productivity

If high-performance p-type metal oxide semiconductors are developed to improve electrical performance, then processing temperature requirements increase, but low processing temperature performance deteriorates

Engineering Contradiction:
Improveelectrical performanceVSAvoidprocessing temperature
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The TeOx-based semiconductor material exhibits self-optimizing properties where the oxygen-deficient structure and chalcogen doping create inherent stability that maintains high electrical performance at low processing temperatures. The material's unique band structure and carrier transport mechanisms enable high hole mobility without requiring high-temperature processing, achieving a self-service effect that eliminates the need for complex thermal management.

Inventive Principle:
Principle #25Self-service

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 resulting p-channel thin film transistor exhibits high hole field-effect mobility and a high on/off current ratio of ~10^7, with improved stability and performance at low processing temperatures, suitable for large-area flexible applications.

Implementation Method 1

a new amorphous p-type semiconductor of TeOx using a deposition technique such as thermal evaporation or sputtering

Methodology Applied
Scientific EffectThermal evaporation: Evaporation

Implementation Method 2

a new amorphous p-type semiconductor of TeOx using a deposition technique such as thermal evaporation or sputtering

Methodology Applied
Scientific EffectSputtering: Sputtering

Data Source

PatentEP4571844A1Semiconductor containing amorphous tellurium oxide, thin film transistor including same, and fabrication method therefor
Publication Date: 2025.06.18 POSTECH ACADEMY INDUSTRY FOUNDATION
  • EP4571844A1 patent drawingFigure 1
  • EP4571844A1 patent drawingFigure 2A~2B
  • EP4571844A1 patent drawingFigure 2C~2D

AI summary

Disclosed are a semiconductor comprising amorphous tellurium oxide, thin film transistor and method of fabricating same. In detail, a semiconductor comprising a chalcogen atom comprising at least one selected from the group consisting of a sulfur atom (S) and a selenium atom (Se); and tellurium composite comprising a tellurium (Te) atom and tellurium oxide. A thin film transistor (TFT) fabricated based on the TeOx channel layer according to the present disclosure exhibits excellent output/transfer characteristics and superior electrical performance with high hole field-effect mobility and a high on/off current ratio of ~107.