Indium Oxide Layer Crystallization for Uniform High-Mobility Transistors
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Solution Overview
Problem
Existing semiconductor devices using silicon-based materials face limitations in carrier mobility, leading to issues such as high parasitic capacitance, power consumption, and integration challenges, while oxide semiconductors like indium gallium zinc oxide suffer from variations in transistor characteristics due to crystal grain boundaries.
Innovation Solution
A method for forming a metal oxide layer involving crystal part formation, crystallization, and alignment of crystal orientations using atomic layer deposition, with indium-based materials, to create a high-mobility metal oxide layer with reduced grain boundaries, thereby enhancing transistor performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silicon-based semiconductor materials are used, then device integration and manufacturing are well-established, but carrier mobility is limited leading to high parasitic capacitance and power consumption
Solution Approach 1:
The patent changes the material parameter from silicon-based semiconductors to oxide semiconductors (In-Ga-Zn-O), fundamentally altering the carrier mobility parameter. This material substitution enables carrier mobility exceeding 10 cm²/Vs, directly resolving the productivity limitation while maintaining device reliability through established manufacturing processes
Solution Approach 2:
The patent employs composite material strategy by combining multiple metal elements (Indium, Gallium, Zinc) with Oxygen to create In-Ga-Zn-O oxide semiconductor. This composite structure leverages the advantageous properties of each element: Indium provides high mobility, Gallium enhances stability, and Zinc contributes to band gap characteristics, achieving superior overall performance
2Productivity
If oxide semiconductors like indium gallium zinc oxide are used, then carrier mobility improves, but transistor characteristics vary due to crystal grain boundaries
Solution Approach 1:
The patent utilizes phase transition control by heating the oxide semiconductor layer to 100°C to 550°C to induce crystallization. This controlled phase transition from amorphous to crystalline state reduces crystal grain boundary effects and promotes uniform crystal orientation, thereby improving transistor characteristic uniformity while preserving high carrier mobility
Solution Approach 2:
The patent applies preliminary action by performing substrate heating treatment before final transistor fabrication steps. This pre-crystallization treatment establishes a uniform crystal structure in advance, ensuring consistent transistor characteristics across the device array and reducing variations that would otherwise require additional manufacturing corrections
3Ease of manufacture
If conventional semiconductor materials and processes are used, then manufacturing processes are established, but parasitic capacitance and power consumption remain high
Solution Approach 1:
The patent changes the semiconductor material parameter to oxide semiconductors with wider band gap and higher mobility, which intrinsically reduce off-state leakage current. This parameter change directly lowers power consumption while the fabrication process maintains compatibility with conventional semiconductor manufacturing techniques, preserving ease of manufacture
Solution Approach 2:
The patent substitutes the conventional silicon-based semiconductor system with an oxide semiconductor system that operates on different physical principles. The oxide semiconductor's unique properties (higher mobility, wider band gap) replace the need for complex circuit designs aimed at reducing parasitic capacitance, achieving lower power consumption through material physics rather than circuit architecture
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 results in a metal oxide layer with high carrier mobility, enabling transistors with improved electrical characteristics, reduced parasitic capacitance, and potential for miniaturization and low power consumption, while maintaining high reliability and integration capabilities.
Implementation Method 1
a first step of forming a crystal part and a second step of forming a crystalline metal oxide layer using the crystal part as a nucleus
Implementation Method 2
crystallization, and alignment of crystal orientations using atomic layer deposition
Data Source
AI summary
A metal oxide layer with high carrier mobility and a method for forming the metal oxide layer are provided. The method for forming the metal oxide layer includes a first step of forming a crystal part and a second step of forming a crystalline metal oxide layer using the crystal part as a nucleus. The metal oxide layer contains indium. The metal oxide layer is formed by an atomic layer deposition method, and a substrate heating temperature is higher than or equal to 150° C. and lower than or equal to 250° C. A crystal orientation of a crystal grain included in the metal oxide layer is <111>, and a crystal orientation of the crystal part is <001>.