Oxide TFT Etching Barrier Layer for Plasma Damage Protection
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Solution Overview
Problem
Conventional oxide thin film transistors (TFTs) face issues such as etching damage to the active layer during electrode formation, exposure to plasma, and the need for additional masks, which degrade electrical performance.
Innovation Solution
A metal etching barrier layer is used that is converted into a non-conductive oxidation layer through oxidation treatment, providing double protection to the channel region and simplifying the manufacturing process by reducing the number of masks required.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an etching barrier layer is provided on the active layer to prevent etch damage, then etching damage to the active layer is prevented, but the active layer may still be damaged by plasma bombardment during barrier layer formation and additional masks are required
Solution Approach 1:
The patent applies preliminary action by forming the metal barrier layer before the etching process, then performing oxidation treatment to convert it to a protective oxide layer. This preliminary protective structure prevents both etch damage and plasma bombardment damage during subsequent processing steps, eliminating the need for additional masks while maintaining active layer integrity
Solution Approach 2:
The patent changes the physical and chemical parameters of the barrier layer by performing oxidation treatment on the metal layer, transforming it from a conductive metal state to a non-conductive oxide state. This parameter change enables the barrier layer to provide protection against plasma bombardment while maintaining its etching protection function, thereby resolving the contradiction between preventing etch damage and avoiding plasma damage
2Ease of manufacture
If the active layer is exposed during source and drain electrode formation, then electrode formation is simplified, but etching damages occur on the active layer surface
Solution Approach 1:
The patent applies preliminary action by forming the metal barrier layer over the active layer before proceeding with source and drain electrode formation. This pre-formed barrier layer protects the active layer surface from etching damages during electrode patterning, allowing simplified electrode formation without compromising active layer integrity
Solution Approach 2:
The metal barrier layer acts as an intermediary protective structure between the active layer and the etching process used for source and drain electrode formation. This intermediary layer prevents direct contact between etching chemicals and the active layer surface, thereby maintaining manufacturing precision while enabling ease of electrode fabrication
3Reliability
If a barrier layer is provided on the active layer to provide protection, then certain protection is achieved, but additional masks are needed to form via holes
Solution Approach 1:
The patent applies universality by designing the metal barrier layer to serve multiple functions: it provides protection against etching damage, protects against plasma bombardment during its formation, and eliminates the need for additional masks during via hole formation. This multi-functional barrier layer reduces device complexity while maintaining reliable active layer protection
Solution Approach 2:
The oxidation treatment transforms the barrier layer's parameters from conductive metal to non-conductive oxide, enabling it to function as both a physical barrier and a protective layer during subsequent processing steps. This parameter change allows the single barrier layer to replace multiple protective structures, reducing the number of masks required
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 solution effectively prevents damage to the channel during etching and subsequent processes, enhancing the electrical stability and performance of the TFT while minimizing process complexity.
Implementation Method 1
The etching barrier layer is a metal layer, and a non-conductive oxidation layer converted from the metal layer by performing an oxidation treatment on the metal layer functions as a channel protective layer
Data Source
AI summary
Embodiments of the invention provide an oxide TFT and a manufacturing method thereof. The oxide thin film transistor comprises: a substrate; a gate electrode formed on the substrate; a gate insulation layer covering the gate electrode; an oxide active layer formed on the gate insulation layer and comprising a source region, a drain region, and a channel between the source region and the drain region; an etching barrier layer entirely covering the active layer and the gate insulation layer; and a source electrode and a drain electrode formed on the etching barrier layer and respectively provided on both sides of the channel. The etching barrier layer is a metal layer. The oxide thin film transistor further comprises a channel protective layer, which is a non-conductive oxidation layer converted from the metal layer by performing an oxidation treatment on the metal layer.