Inorganic Oxide Semiconductor Layer for Charge Transfer
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Solution Overview
Problem
Conventional stacked imaging devices face challenges in efficiently transferring electric charges due to complex manufacturing processes and lack of specific material compositions, particularly in the correlation between carrier mobility and energy levels in semiconductor layers, leading to potential signal delay and reduced imaging quality.
Innovation Solution
Incorporating an inorganic oxide semiconductor material layer with zinc (Zn) and tin (Sn) atoms, expressed as Zn a Sn b O c, where a + b + c = 1.00 and b > a, to enhance charge transfer characteristics, along with the addition of 5d transition metals like tungsten, tantalum, or hafnium to reduce oxygen defects and improve energy level alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional structures are used for storing and transferring signal charges, then the imaging device can function, but high-speed transfer is required to avoid signal charge delay
Solution Approach 1:
The patent changes the material parameter of the semiconductor layer from conventional materials to inorganic oxide semiconductor material, which inherently provides higher carrier mobility. This material parameter change enables faster charge transfer speed without requiring complex structural modifications or high-speed transfer mechanisms, thereby resolving the contradiction between transfer speed and time delay.
2Reliability
If specific material compositions are not defined, then manufacturing is flexible, but carrier mobility and energy level correlation is not optimized
Solution Approach 1:
The patent specifies precise material composition parameters for the inorganic oxide semiconductor layer, including the ratio relationship between metal atoms (e.g., Zn and Sn atoms where Sn/Zn ratio is 0.1 to 10). By defining these compositional parameters, the patent optimizes carrier mobility and energy level alignment, thereby improving charge transfer efficiency while maintaining manufacturing feasibility through clear parameter guidelines.
Solution Approach 2:
The patent employs composite inorganic oxide semiconductor materials containing multiple metal elements (such as Zn-Sn-O, Zn-In-O, or Zn-Sn-In-O systems). These composite materials combine the advantages of different metal oxides to achieve superior carrier mobility and energy level characteristics that cannot be obtained with single-element materials, thus improving reliability without excessive complexity.
3Ease of manufacture
If the semiconductor layer structure is simplified, then manufacturing is easier, but charge transfer characteristics may be insufficient
Solution Approach 1:
The patent uses composite inorganic oxide semiconductor materials that can be deposited using conventional sputtering or atomic layer deposition techniques. The composite nature of these materials provides excellent charge transfer characteristics while maintaining compatibility with existing manufacturing processes, thus achieving both ease of manufacture and high reliability.
Solution Approach 2:
The patent optimizes key parameters of the semiconductor layer including thickness (50-500 nm), carrier concentration (10^16-10^19 cm^-3), and mobility (>10 cm²/Vs). By controlling these parameters within specific ranges, the patent achieves superior charge transfer characteristics with a relatively simple single-layer structure, avoiding the need for complex multilayer designs while maintaining high manufacturing ease.
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 configuration simplifies the structure while improving charge transfer efficiency, reducing noise and enhancing imaging quality by ensuring effective depletion of charge storage portions and minimizing dark current.
Implementation Method 1
a photoelectric conversion layer formed on the semiconductor layer
Data Source
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AI summary
An imaging device includes a photoelectric conversion unit in which a first electrode 21, a photoelectric conversion layer 23A, and a second electrode 22 are stacked. In the imaging device, an inorganic oxide semiconductor material layer 23B is formed between the first electrode 21 and the photoelectric conversion layer 23A. The inorganic oxide semiconductor material layer 23B contains zinc (Zn) atoms and tin (Sn) atoms, and, when expressed by ZnaSnbOc, satisfies the following conditions: a + b + c = 1.00, and b > a.