Oxide Semiconductor Transistor for High Mobility and Low Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor devices face challenges in achieving high field-effect mobility, stable electrical characteristics, low off-state current, low power consumption, and high reliability, while also requiring a small area occupation and high integration.
Innovation Solution
A semiconductor device is designed with a structure that includes multiple transistors and capacitors, utilizing oxide semiconductors with specific layer configurations and materials, such as In-Ga-Zn oxide, to enhance field-effect mobility and reduce off-state current, and incorporates a back gate electrode to manage electrical characteristics and reduce power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If amorphous silicon is used for transistors in large-sized display devices, then the device can be formed using established techniques on large substrates, but the field-effect mobility is insufficient for high-performance applications
Solution Approach 1:
The patent changes the material parameter from conventional amorphous silicon to oxide semiconductor, which fundamentally alters the electrical characteristics to achieve high field-effect mobility while maintaining compatibility with existing manufacturing processes
Solution Approach 2:
The patent uses composite material structures including oxide semiconductor layers combined with specific insulating materials (such as silicon oxide, silicon nitride) to create a transistor system that achieves both high mobility and manufacturing compatibility
2Reliability
If polycrystalline silicon is used to achieve high field-effect mobility, then high-performance display devices can be obtained, but the manufacturing process becomes more complex requiring high-temperature heat treatment or laser light treatment
Solution Approach 1:
The patent changes the material parameter from polycrystalline silicon to oxide semiconductor, which achieves high field-effect mobility through inherent material properties rather than requiring complex post-processing treatments
Solution Approach 2:
The patent extracts and eliminates the complex high-temperature heat treatment or laser light treatment steps from the manufacturing process by using oxide semiconductor material that can be formed using simpler, established techniques
3Device complexity
If conventional transistors are used, then the device structure is simpler, but the off-state current is higher leading to increased power consumption
Solution Approach 1:
The patent changes the semiconductor material parameter to oxide semiconductor, which inherently provides extremely low off-state current due to its wide bandgap properties, thereby reducing power consumption
Solution Approach 2:
The patent combines oxide semiconductor with specific insulating materials and electrode structures to create a composite transistor system that maintains low off-state current while managing device complexity
4Area of moving object
If more transistors are integrated to reduce area occupation, then the device becomes more compact, but the electrical characteristics stability becomes more difficult to maintain
Solution Approach 1:
The patent changes the material parameter to oxide semiconductor, which provides stable electrical characteristics even in highly integrated configurations due to its low leakage current and consistent performance properties
Solution Approach 2:
The patent creates a universal transistor design using oxide semiconductor that can be consistently manufactured and performs reliably across different integration densities, allowing area reduction without sacrificing stability
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 device achieves high field-effect mobility, stable electrical characteristics, low off-state current, and low power consumption, while occupying a small area and enabling high integration, thereby improving reliability and productivity.
Implementation Method 1
an oxide semiconductor can be formed by a sputtering method or the like, and thus can be used for a channel formation region of a transistor
Implementation Method 2
incorporates a back gate electrode to manage electrical characteristics
Data Source
AI summary
Disclosed is a semiconductor device having a first transistor and a second transistor over the first transistor. The first transistor includes a first semiconductor, and the second transistor includes an oxide semiconductor that is different from the first semiconductor. A gate of the first transistor is electrically connected to a source or drain electrode of the second transistor. The second transistor has a semiconductor layer including the oxide semiconductor over the source and drain electrodes and a gate electrode over the semiconductor layer with an insulating layer therebetween.