Zn-Sn-Si-O Oxide Semiconductor for Stable TFT Characteristics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Oxide semiconductors like ZTO face challenges in maintaining stable TFT characteristics due to oxygen defects and hydrogen diffusion during the formation of passivation layers, leading to conductive semiconductor layers and unstable switching behavior, which affects the performance and cost-effectiveness of display devices.
Innovation Solution
Incorporating Si into ZTO-based oxide semiconductors to form Zn-Sn-Si-O thin-film transistors, with specific atomic ratios of Zn, Sn, and Si, to stabilize the semiconductor layer and prevent defects, thereby ensuring stable TFT characteristics and reduced material costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If plasma CVD or sputtering is used to form a passivation layer on oxide semiconductor film, then the passivation layer can be formed to protect the semiconductor, but oxygen defects are generated in the oxide semiconductor and TFT characteristics are deteriorated
Solution Approach 1:
The patent applies preliminary action by forming a protective layer (such as a nitrogen-containing insulating layer or organic protective layer) on the oxide semiconductor film before forming the passivation layer. This protective layer prevents oxygen defects from being generated during the subsequent plasma CVD or sputtering processes, thereby maintaining TFT characteristics stability while still allowing passivation layer formation.
2Reliability
If In-containing oxide semiconductors are used to achieve high mobility, then carrier mobility is improved, but material cost increases due to In being a rare metal
Solution Approach 1:
The patent applies parameter changes by substituting the rare metal In with common metals such as Al, Ga, or their combinations. By adjusting the composition parameters (metal ratios, oxygen content) and processing conditions (heating temperature, atmosphere), the patent achieves high carrier mobility in In-free oxide semiconductors, thereby reducing material cost while maintaining reliability.
3Reliability
If hydrogen is introduced into oxide semiconductor film during passivation layer formation, then the passivation process is completed, but hydrogen diffusion causes excessive carrier increase and TFT characteristics are deteriorated
Solution Approach 1:
The patent applies preliminary action by forming a hydrogen barrier layer (such as a nitrogen-containing insulating layer or specific oxide layer) on the oxide semiconductor film before forming the passivation layer. This barrier layer prevents hydrogen from diffusing into the semiconductor during passivation layer formation, thereby maintaining TFT switching characteristics while still completing the passivation process.
Solution Approach 2:
The patent uses an intermediary layer (protective layer or barrier layer) that is placed between the oxide semiconductor film and the passivation layer. This intermediary layer serves as a mediator that allows the passivation process to proceed while blocking harmful hydrogen diffusion, thus protecting the semiconductor characteristics.
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 use of Zn-Sn-Si-O thin-film transistors achieves stable and high-mobility TFT characteristics, preventing oxygen defect formation and hydrogen diffusion, resulting in reliable display devices with improved yield and reduced production costs.
Implementation Method 1
a sputtering target for forming an oxide as described above into a film
Data Source
AI summary
There is provided an oxide for semiconductor layers of thin-film transistors, which oxide can provide thin-film transistors with excellent switching characteristics and by which oxide favorable characteristics can stably be obtained even after the formation of passivation layers. The oxide to be used for semiconductor layers of thin-film transistors according to the present invention includes Zn, Sn, and Si.