Metal Oxide Semiconductor Device Oxygen Vacancy Control
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Solution Overview
Problem
Current semiconductor devices using oxide semiconductors face challenges in achieving stable and reliable electrical characteristics due to issues with resistance and oxygen vacancy, which affect their performance and reliability.
Innovation Solution
A method for manufacturing semiconductor devices involves forming a first and second metal oxide layer with a heat treatment process using a layer containing aluminum, titanium, or tungsten to lower the resistance of the second region, and a third metal oxide layer with a higher In content than Ga, enhancing the electrical characteristics and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal oxide layer is used as a semiconductor layer, then field-effect mobility is improved, but resistance stability deteriorates due to oxygen vacancy
Solution Approach 1:
A first metal oxide layer is introduced as an intermediary between the substrate and the second metal oxide layer. This first layer acts as a buffer that supplies oxygen to the second layer, preventing oxygen vacancy formation while maintaining the high field-effect mobility benefits of metal oxide semiconductor layers.
Solution Approach 2:
The first metal oxide layer is formed in advance before the second metal oxide layer. This preliminary layer is prepared with specific characteristics (such as being in an oxygen-excess state) to proactively prevent oxygen vacancy formation in the subsequent second layer, rather than addressing the problem after it occurs.
2Reliability
If heat treatment is performed to lower resistance, then electrical conductivity is improved, but oxygen vacancy increases
Solution Approach 1:
The first metal oxide layer serves as an oxygen reservoir that compensates for oxygen loss during heat treatment of the second metal oxide layer. When the second layer undergoes heat treatment to improve conductivity, the first layer supplies oxygen to prevent excessive oxygen vacancy formation, thus maintaining both conductivity improvement and oxygen stability.
3Ease of manufacture
If a single metal oxide layer is used, then manufacturing is simplified, but electrical characteristics stability deteriorates
Solution Approach 1:
The semiconductor structure is segmented into two distinct metal oxide layers, each with specific functions. The first layer is optimized for oxygen supply and stability, while the second layer is optimized for high field-effect mobility. This segmentation allows each layer to specialize in its function, achieving overall stability without significantly complicating the manufacturing process.
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 approach results in semiconductor devices with improved electrical characteristics and reliability by reducing resistance and minimizing oxygen vacancy, leading to higher field-effect mobility and stable performance.
Implementation Method 1
performing heat treatment to lower the resistance of the second region of the first metal oxide layer and the resistance of the second metal oxide layer
Data Source
AI summary
A semiconductor device with favorable electrical characteristics, a semiconductor device with stable electrical characteristics, or a highly reliable semiconductor device or display device is provided. A first insulating layer and a first conductive layer are stacked over a first region of a first metal oxide layer. A first layer is formed in contact with a second metal oxide layer and a second region of the first metal oxide layer that is not overlapped by the first insulating layer. Heat treatment is performed to lower the resistance of the second region and the second metal oxide layer. A second insulating layer is formed. A second conductive layer electrically connected to the second region is formed over the second insulating layer. Here, the first layer is formed to contain at least one of aluminum, titanium, tantalum, and tungsten.