Inverted Oxide TFT Electrode Stack for Process Simplification
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Solution Overview
Problem
The increased production cost and complexity in manufacturing oxide thin film transistor array substrates due to the need for additional photoetching processes to protect the oxide active layer pattern during the formation of source and drain electrodes, which requires an etch stopping layer.
Innovation Solution
Reversing the order of electrode formation by placing the source and drain electrodes below the oxide active layer pattern, with the gate electrode located below them, eliminating the need for an etch stopping layer and reducing the number of photoetching processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an etch stopping layer is added to protect the oxide active layer pattern during source/drain electrode formation, then the oxide active layer pattern is protected from damage, but the manufacturing process complexity and production cost increase due to additional photoetching processes
Solution Approach 1:
The patent inverts the conventional electrode formation sequence by forming source/drain electrodes before the oxide active layer pattern instead of after. This reversal eliminates the need for an etch stopping layer and additional photoetching processes, as the electrodes are already in place and do not require protection during subsequent etching steps. The inversion resolves the contradiction by maintaining pattern protection while simplifying the manufacturing process.
Solution Approach 2:
The patent performs preliminary action by forming source/drain electrodes and their contact holes in advance before forming the oxide active layer pattern. This preliminary electrode formation allows the subsequent oxide layer deposition to naturally protect the electrodes without requiring additional etch stopping layers. The preliminary action eliminates process complexity while ensuring electrode protection.
2Reliability
If an etch stopping layer is added to protect the oxide active layer pattern, then the oxide active layer pattern is protected from being destroyed, but the production cost increases due to additional photoetching processes
Solution Approach 1:
By inverting the formation sequence to create source/drain electrodes before the oxide active layer pattern, the patent eliminates the need for etch stopping layers and additional photoetching processes. This inversion maintains reliable pattern protection while reducing production costs by streamlining the manufacturing process to use standard photoetching steps only.
3Ease of manufacture
If source/drain electrodes are formed above the oxide active layer pattern using conventional methods, then the electrode formation process is straightforward, but the oxide active layer pattern is destroyed by the etching solution
Solution Approach 1:
The patent applies inversion by forming source/drain electrodes and their contact holes through the gate insulating layer before depositing the oxide active layer pattern. This sequence reversal ensures that the oxide layer is deposited over existing electrode structures, naturally protecting them from damage during subsequent processing while maintaining ease of manufacture through standard deposition and etching techniques.
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
This approach prevents damage to the oxide active layer pattern during etching, reduces production costs, and improves productivity by simplifying the manufacturing process.
Implementation Method 1
a gate insulating layer, an oxide active layer pattern, a source electrode and a drain electrode, wherein the source electrode and the drain electrode are located below the oxide active layer pattern; the gate electrode is located below the source electrode and the drain electrode; and the gate insulating layer is located between the gate electrode and the source electrode/the drain electrode
Data Source
AI summary
Provided are oxide thin-film transistor and display device employing the same, and method for manufacturing an oxide thin-film transistor array substrate. A source electrode and a drain electrode are located below an oxide active layer pattern, and a gate electrode is located below the source electrode and the drain electrode, and the gate insulating layer is located between the gate electrode and the source electrode/the drain electrode.