Metal Oxide Protective Film for Oxide Semiconductor Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The electrical conductivity of oxide semiconductors can vary due to the entry of water or hydrogen and release of oxygen during the manufacturing process of semiconductor devices, leading to unstable electric characteristics.
Innovation Solution
A semiconductor device with a metal oxide film as a protective layer, formed using materials from the same group as the oxide semiconductor, is used to suppress the entry and diffusion of water or hydrogen and the release of oxygen, ensuring a stable interface and reliable performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional protective film is used over the oxide semiconductor film, then the device structure is simple, but water or hydrogen enters the oxide semiconductor film and oxygen is released, causing variation in electric characteristics
Solution Approach 1:
The protective film is divided into multiple layers: a first protective film in direct contact with the oxide semiconductor film and a second protective film formed over the first protective film. This segmentation allows the first layer to provide barrier functionality while the second layer provides additional protection, resolving the contradiction between reliability and structural simplicity.
Solution Approach 2:
The first protective film acts as an intermediary barrier between the oxide semiconductor film and the external environment. It prevents water and hydrogen from reaching the oxide semiconductor film while allowing the device structure to remain relatively simple.
2Reliability
If the oxide semiconductor film is exposed during manufacturing, then the manufacturing process is simple, but electrical conductivity changes due to water or hydrogen entry and oxygen release
Solution Approach 1:
The first protective film is formed over the oxide semiconductor film before subsequent manufacturing steps. This preliminary protective action prevents water and hydrogen from entering the oxide semiconductor film during manufacturing processes, maintaining electrical conductivity stability without significantly complicating the manufacturing sequence.
3Reliability
If no protective film is used, then the device structure is simplest, but the interface characteristics are unstable and electric characteristics vary
Solution Approach 1:
The first protective film is specifically positioned in direct contact with the oxide semiconductor film where interface stability is critical. This localized quality enhancement provides the necessary interface stability without requiring complex structures throughout the entire device.
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 solution provides a semiconductor device with stable electric characteristics and high reliability by preventing water and hydrogen entry and oxygen release, resulting in improved semiconductor performance.
Implementation Method 1
The metal oxide film can suppress entry and diffusion of water or hydrogen into the oxide semiconductor film
Implementation Method 2
release of oxygen from the oxide semiconductor film can be suppressed
Data Source
AI summary
To provide a semiconductor device including an oxide semiconductor, which has stable electric characteristics and has high reliability. To provide a method for manufacturing the semiconductor device. The semiconductor device includes a gate electrode, a gate insulating film formed over the gate electrode, an oxide semiconductor film formed over the gate insulating film, a source electrode and a drain electrode formed over the oxide semiconductor film, and a protective film. The protective film includes a metal oxide film, and the metal oxide film has a film density of higher than or equal to 3.2 g/cm3.