Fluorine-Graded Oxide Semiconductor Layer for TFT Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Oxide semiconductor thin film transistors (TFTs) are susceptible to oxygen and hydrogen, leading to reliability issues due to their electrical characteristics.
Innovation Solution
Incorporating fluorine into the oxide semiconductor layer, particularly in regions close to the gate insulating layer, with a higher fluorine concentration than in contact regions, to stabilize the channel region and reduce contact resistance, thereby enhancing the reliability of the TFTs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fluorine is incorporated into the oxide semiconductor layer, then reliability and stability are improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies parameter changes by incorporating fluorine into the oxide semiconductor layer to alter its electrical and chemical properties. This changes the material composition parameter, which improves reliability by reducing susceptibility to oxygen and hydrogen while maintaining the desired electrical characteristics for TFT operation.
Solution Approach 2:
The patent uses composite materials by creating an oxide semiconductor layer that combines multiple elements (oxide semiconductor matrix with fluorine incorporation). This composite structure allows the material to exhibit both the inherent properties of oxide semiconductors and the stabilizing effects of fluorine, thereby improving reliability without fundamentally changing the manufacturing process.
2Reliability
If fluorine concentration is increased in the region close to the gate insulating layer, then contact resistance is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies local quality by creating a non-uniform fluorine concentration distribution within the oxide semiconductor layer. Specifically, the fluorine concentration is higher in the region close to the gate insulating layer and lower in the contact regions. This localized variation in composition allows optimization of electrical properties in different areas of the device without requiring uniform treatment throughout the entire layer.
Solution Approach 2:
The patent uses preliminary action by pre-establishing the fluorine concentration gradient during the deposition process. The fluorine is incorporated into the oxide semiconductor layer in a controlled manner during formation, creating the desired concentration distribution before subsequent processing steps. This preliminary establishment of the concentration profile simplifies later manufacturing steps.
Data Source
AI summary
A thin film transistor includes: a gate electrode; a gate insulating layer above the gate electrode; an oxide semiconductor layer disposed above the gate insulating layer; and a source electrode and a drain electrode disposed above the oxide semiconductor layer and electrically connected to the oxide semiconductor layer, wherein metallic elements included in the oxide semiconductor layer include at least indium (In), fluorine is included in a region which is an internal region in the oxide semiconductor layer and is close to the gate insulating layer, and a fluorine concentration of the region close to the gate insulating layer in the oxide semiconductor layer is higher than a fluorine of a contact region for the source electrode or the drain electrode in the oxide semiconductor layer.