Oxide-Semiconductor Radiation Detector With Thin Oxide Layer Stability
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Solution Overview
Problem
Existing radiation detectors using oxide semiconductor channels face reliability issues due to oxygen vacancies and hole trapping in the insulating layers, leading to characteristic variations under radiation exposure.
Innovation Solution
A radiation detector configuration that includes a transistor with an oxide semiconductor channel, a photoelectric converting layer, a wavelength converting layer, and an oxide layer with a thickness of 50 nm or less, which reduces hole trapping and enhances reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an insulating layer is formed to supply oxygen to the oxide semiconductor layer, then oxygen vacancies are reduced, but hole trapping occurs leading to characteristic variations
Solution Approach 1:
The patent extracts the oxygen supply function from a thick insulating layer and concentrates it in a thin oxide layer (50 nm or less) positioned between the oxide semiconductor layer and the photoelectric converting layer. This thin oxide layer provides necessary oxygen to reduce vacancies while minimizing the volume that could trap holes, thus resolving the contradiction between stability and hole trapping.
Solution Approach 2:
The patent applies local quality by creating a specific oxide layer with distinct properties (thin thickness, specific position) only where needed - between the oxide semiconductor layer and photoelectric converting layer. This localized approach ensures oxygen supply exactly where required while avoiding unnecessary insulating material that could trap holes in other regions.
2Reliability
If a thick insulating layer is used to supply oxygen, then oxygen vacancies are reduced, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent extracts the essential oxygen supply function from a potentially thick insulating layer structure and implements it through a thin oxide layer (50 nm or less). This extraction simplifies the overall device structure while maintaining the critical oxygen supply capability needed to reduce oxygen vacancies in the oxide semiconductor layer.
Solution Approach 2:
The patent changes the thickness parameter of the oxide layer to 50 nm or less, which is significantly thinner than conventional insulating layers. This parameter change maintains sufficient oxygen supply for vacancy reduction while simplifying the device structure and reducing manufacturing complexity.
3Reliability
If the oxide layer thickness is increased to improve oxygen supply, then oxygen vacancies are reduced, but hole trapping increases causing characteristic variations
Solution Approach 1:
The patent optimizes the oxide layer thickness parameter to 50 nm or less, finding the optimal balance point where sufficient oxygen is supplied to reduce vacancies while the thickness remains low enough to minimize hole trapping. This precise parameter control ensures stable characteristics under radiation exposure.
Solution Approach 2:
The patent applies partial action by providing just enough oxygen supply through the thin oxide layer to reduce oxygen vacancies to acceptable levels, rather than using excessive insulating material. This partial approach minimizes hole trapping while achieving the necessary vacancy reduction for reliable operation.
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 proposed configuration improves the reliability of the radiation detector by minimizing characteristic variations under both visible light and radiation exposure, ensuring stable operation.
Implementation Method 1
a wavelength converting layer facing the photoelectric converting layer and capable of emitting visible light based on radioactive rays absorbed by the wavelength converting layer
Implementation Method 2
a photoelectric converting layer connected to the transistor
Data Source
AI summary
A radiation detector according to an embodiment of the present invention includes: a transistor in which an oxide semiconductor layer is used in a channel of the transistor; a photoelectric converting layer connected to the transistor; a wavelength converting layer facing the photoelectric converting layer and capable of emitting visible light based on radioactive rays absorbed by the wavelength converting layer; and an oxide layer in contact with the oxide semiconductor layer between the transistor and the photoelectric converting layer, wherein a thickness of the oxide layer is 50 nm or less.