Array Substrate Passivation via Aluminum Oxidation for TFT Reliability
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Solution Overview
Problem
Current methods for preparing aluminum oxide passivation layers in thin film transistor devices are inadequate for large-size production due to the brittleness of alumina targets and the high hydrogen content in silicon nitride films, which affects the performance of thin film transistors.
Innovation Solution
A method involving the deposition of a first passivation layer, an original metal layer, and an oxygen source layer on a substrate, followed by heat treatment to form a double-layer passivation structure, where the original metal layer is oxidized and the oxygen source layer is deoxidized, facilitating the formation of a large-size metal oxide passivation layer with improved water and oxygen blocking capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If physical sputtering method is used to prepare aluminum oxide passivation layer, then the passivation layer can be formed, but the alumina target is brittle and difficult to make for large-size deposition
Solution Approach 1:
The passivation layer preparation is divided into two separate steps: first forming a metal layer (e.g., aluminum), then oxidizing it in a subsequent oxidation step. This segmentation allows the metal layer to be deposited using conventional sputtering with standard metal targets, avoiding the brittleness issue of large-size alumina targets while still achieving the desired aluminum oxide passivation layer.
Solution Approach 2:
The metal layer is prepared in advance through physical sputtering, and then the oxidation is performed as a preliminary action in a separate step. This preliminary formation of the metal layer allows using stable, non-brittle metal targets rather than fragile ceramic alumina targets, enabling large-size deposition.
2Reliability
If silicon nitride is used to make passivation layer, then water vapor isolation ability is improved, but hydrogen content becomes too high and deteriorates thin film transistor performance
Solution Approach 1:
The invention changes the material parameter from silicon nitride to aluminum oxide (formed by oxidizing aluminum layer). Aluminum oxide provides comparable or better water vapor isolation ability while eliminating the hydrogen incorporation problem associated with silicon nitride deposition using silane and ammonia gases.
3Ease of manufacture
If silicon dioxide is used to make passivation layer, then the passivation layer can be formed easily, but water vapor isolation ability is poor
Solution Approach 1:
The invention changes the material parameter from silicon dioxide to aluminum oxide. While silicon dioxide is easier to deposit, aluminum oxide provides superior water vapor isolation properties. The oxidation step converts the easily-deposited aluminum metal layer into aluminum oxide, achieving both ease of manufacture and high reliability.
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 enables the easy production of a large-size metal oxide passivation layer with a double-layer structure, enhancing the ability to isolate water and oxygen, thus improving the performance and durability of thin film transistors.
Implementation Method 1
heat-treating the oxygen source layer and the original metal layer, wherein the original metal layer is oxidized to form a second passivation layer
Implementation Method 2
performing a heat treatment on the oxygen source layer and the original metal layer over a preset duration at a preset temperature
Implementation Method 3
the oxygen source layer is deoxidized to form a deoxidation layer
Implementation Method 4
depositing the original metal layer of a first thickness on the first passivation layer by a physical deposition process
Data Source
AI summary
The present disclosure provides a method of manufacturing an array substrate, the array substrate, and a display device. The method of manufacturing the array substrate includes: a step of preparing a substrate; a step of preparing a driving circuit layer on the substrate; a step of preparing a first passivation layer on the driving circuit layer; a step of preparing an original metal layer on the first passivation layer; a step of preparing an oxygen source layer on the original metal layer; a step of heat-treating the oxygen source layer and the original metal layer, wherein the original metal layer is oxidized to form a second passivation layer.