Metal Oxide Semiconductor Fabrication With In-Air-Free Plasma Insulation
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Solution Overview
Problem
Current semiconductor devices using metal oxide semiconductors face challenges in achieving stable and high-productivity fabrication methods that result in reliable electrical characteristics and high-performance display devices.
Innovation Solution
A method involving the formation of a semiconductor device with a metal oxide semiconductor layer, followed by specific plasma treatments and the use of insulating layers formed using mixed gases containing silicon, oxidizing gases, and ammonia, to enhance electrical characteristics and productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional fabrication methods are used without specific plasma treatment, then the fabrication process is simpler, but electrical characteristics are unstable and reliability is poor
Solution Approach 1:
The patent applies preliminary plasma treatment to the substrate before forming the semiconductor layer. This preliminary action modifies the substrate surface to improve subsequent layer formation and electrical characteristics, resolving the contradiction by preparing the surface in advance to ensure stability without complicating the main fabrication process.
Solution Approach 2:
The patent changes physical and chemical parameters during plasma treatment, including gas composition (mixed gas of oxidizing gas and reducing gas), plasma power, and treatment time. These parameter changes optimize the surface conditions for better electrical characteristics while maintaining a controlled fabrication process.
2Reliability
If multiple plasma treatments and insulating layers are added, then electrical stability and reliability improve, but fabrication time and productivity decrease
Solution Approach 1:
The patent combines multiple plasma treatment steps into a single integrated process with specific gas sequences. Instead of separate treatments, the mixed gas plasma treatment accomplishes multiple objectives simultaneously, improving electrical stability without proportionally increasing fabrication time.
Solution Approach 2:
The patent maintains continuous plasma treatment with optimized gas flow and timing. The plasma treatment continues through the formation of insulating layers without interruption, ensuring consistent electrical characteristics while minimizing idle time and maintaining high productivity.
3Reliability
If ammonia gas is added to the mixed gas for insulating layer formation, then nitrogen oxide release is controlled and electrical stability improves, but process complexity increases
Solution Approach 1:
The patent introduces ammonia gas as a specific parameter change in the mixed gas composition. This chemical parameter modification controls nitrogen oxide release during plasma treatment, ensuring consistent threshold voltage and electrical stability while maintaining a manageable gas mixture for fabrication.
4Reliability
If plasma treatment with oxidizing and reducing gases is performed, then impurity diffusion is reduced and electrical characteristics improve, but energy consumption and process time increase
Solution Approach 1:
The patent optimizes plasma treatment parameters including gas composition ratios, plasma power, and treatment duration. By carefully controlling these parameters, the process achieves effective impurity control and electrical characteristic improvement while minimizing unnecessary energy consumption and process time.
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 method provides semiconductor devices with improved electrical stability and reliability, reducing defects and enhancing the performance of display devices by controlling the release of nitrogen oxides and ammonia, thereby maintaining consistent threshold voltage and reducing impurity diffusion.
Implementation Method 1
The first insulating layer is formed by a plasma-enhanced chemical vapor deposition method using a mixed gas including a first gas containing silicon, a second oxidizing gas, and an ammonia gas
Implementation Method 2
a step of performing first plasma treatment using a mixed gas including a first oxidizing gas and a reducing gas on a region where the semiconductor layer is exposed
Data Source
AI summary
A semiconductor device with favorable electrical characteristics is provided. A semiconductor device with stable electrical characteristics is provided. A highly reliable display device is provided. A method for fabricating the semiconductor device includes a step of forming a semiconductor layer including a metal oxide; a step of forming, over the semiconductor layer, a first conductive layer and a second conductive layer that are apart from each other over the semiconductor layer; a step of performing plasma treatment using a mixed gas including an oxidizing gas and a reducing gas on a region where the semiconductor layer is exposed; a step of forming a first insulating layer over the semiconductor layer, the first conductive layer, and the second conductive layer; and a step of forming a second insulating layer over the first insulating layer. The first insulating layer is formed by a plasma-enhanced chemical vapor deposition method using a mixed gas including a gas containing silicon, an oxidizing gas, and an ammonia gas. The first insulating layer is formed successively after the plasma treatment without exposure to the air.