Nitrogen-Doped IGZO Thin Film Transistor Substrate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current oxide thin film transistors, particularly those using Indium-Galium-Zinc Oxide (IGZO) materials, face reliability issues due to defects such as oxygen vacancies, which degrade their performance over time, and existing methods to enhance reliability, like plasma treatment or aluminum oxide deposition, increase manufacturing costs and complexity.
Innovation Solution
Doping nitrogen into the IGZO semiconductor material to occupy oxygen vacancies, thereby enhancing the reliability of the thin film transistor substrate without altering its characteristics under constant current stress conditions, using existing manufacturing equipment and processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional oxide semiconductor materials (IGZO) are used in thin film transistors, then manufacturing cost and process complexity are kept low, but reliability degrades over time due to oxygen vacancies and defects
Solution Approach 1:
The patent changes the chemical composition parameter of the oxide semiconductor material by doping nitrogen into the IGZO lattice. This compositional modification allows nitrogen atoms to occupy oxygen vacancy sites, thereby reducing defect density and improving transistor reliability without requiring additional manufacturing steps or equipment
Solution Approach 2:
Nitrogen acts as an intermediary element that fills the oxygen vacancies in the IGZO structure. By introducing this intermediary dopant, the patent resolves the reliability issue caused by oxygen vacancies without needing complex additional processes such as plasma treatment or aluminum oxide deposition
2Reliability
If plasma treatment or aluminum oxide deposition is applied to enhance reliability, then transistor reliability improves, but manufacturing cost and process complexity increase
Solution Approach 1:
The patent merges the reliability enhancement function into the existing oxide semiconductor material deposition process itself. By doping nitrogen during the sputtering process, the patent combines material deposition with defect prevention in a single step, eliminating the need for separate plasma treatment or aluminum oxide deposition steps
3Reliability
If nitrogen is doped into IGZO material, then reliability improves by occupying oxygen vacancies, but manufacturing process complexity increases
Solution Approach 1:
The patent implements self-service by using the existing sputtering equipment and process parameters to achieve nitrogen doping. The nitrogen gas is introduced during normal deposition, and the process conditions are optimized so that the existing equipment performs the doping function without requiring additional specialized equipment or complex process changes
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 nitrogen-doped IGZO substrate exhibits improved reliability and maintains high carrier mobility, reducing defects and extending the lifespan of the transistor without additional manufacturing costs or complexity, as demonstrated by enhanced performance under both positive bias stress with and without incident light.
Implementation Method 1
Doping nitrogen into the IGZO semiconductor material to occupy oxygen vacancies
Implementation Method 2
as for the depositing method for a-IGZO, the sputtering method is the best for commercializing
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
The present disclosure relates to a thin film transistor substrate having a high reliability oxide semiconductor material including a metal oxide semiconductor material. A thin film transistor substrate includes a substrate (SUB), a gate electrode (G) disposed on the substrate (SUB), a semiconductor layer (A) including an oxide semiconductor material combining one or more of indium, gallium and zinc, oxygen, and a doping material. The doping material may be a group 15 or 16 gaseous element. The semiconductor layer (A) has a channel area (CA) overlapping with the gate electrode (G) with a gate insulating layer (GI), a source area (SA) extended from one side of the channel area (CA), and a drain area (DA) extended from another side of the channel area (CA), a source electrode (S) connected to the source area (SA), and a drain electrode (D) connected to the drain area (DA).