Oxide Target Material With Refined Grains for Uniform Element Distribution
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Solution Overview
Problem
Existing oxide target materials for thin film transistors face challenges due to large grain sizes and non-uniform element distribution, leading to material composition deviations and cracking, which are exacerbated by the difficulty of substituting rare earth oxides with larger ionic radii during sintering.
Innovation Solution
A method involving specific atomic molar ratios and controlled sintering processes to produce an oxide target material with refined grain sizes and uniform element distribution, using indium, gallium/zinc, cerium/praseodymium/yterbium/dysprosium, and scandium/titanium/germanium/antimony oxides, with precise temperature and gas environment control to inhibit grain growth and ensure uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rare earth oxides are doped into oxide target materials, then optical stability of oxide thin film transistor devices is improved, but element distribution uniformity deteriorates due to accumulation at grain boundaries
Solution Approach 1:
The patent changes the grain size parameter from conventional large sizes (10-30 μm) to ultra-fine sizes (1-10 μm, preferably 3-7 μm). This parameter change reduces the total grain boundary area and prevents rare earth element accumulation, maintaining element distribution uniformity while preserving optical stability benefits
Solution Approach 2:
The patent uses composite oxide materials containing multiple metal oxides (In2O3, Ga2O3, ZnO, SnO2) with rare earth oxide dopants. The composite structure allows rare earth elements to be distributed throughout the matrix without excessive grain boundary accumulation, balancing optical stability enhancement with compositional uniformity
2Stability of the object's composition
If grain size is reduced in oxide target materials, then element distribution uniformity is improved, but manufacturing complexity increases due to controlled sintering requirements
Solution Approach 1:
The patent performs preliminary powder preparation including ball milling and classification before sintering to achieve uniform particle size distribution (1-10 μm). This preliminary action ensures homogeneous raw material distribution, simplifying the subsequent sintering process and reducing the need for complex temperature control during sintering
Solution Approach 2:
The patent employs continuous sintering processes with controlled heating rates and holding times to maintain uniform grain growth throughout the target material. The continuous action ensures consistent ultra-fine grain structure (1-10 μm) throughout the entire material volume, achieving uniform element distribution without requiring complex multi-stage sintering
3Ease of manufacture
If conventional sintering processes are used, then manufacturing simplicity is maintained, but grain size becomes too large leading to material composition deviation
Solution Approach 1:
The patent modifies sintering parameters including reducing heating rate (0.5-5°C/min), extending holding time (2-24 hours), and optimizing sintering temperature (900-1100°C). These parameter changes enable ultra-fine grain size control (1-10 μm) while maintaining relatively simple single-stage sintering processes
Solution Approach 2:
The patent performs preliminary powder classification to achieve uniform particle size distribution (1-10 μm) before sintering. This preliminary action ensures that conventional simple sintering processes can produce uniform ultra-fine grains, as the starting material already has the desired grain size distribution
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 resulting oxide target material achieves high density, small grain size, and uniform microstructure, enhancing the quality and stability of thin films for high-end display applications.
Implementation Method 1
step 3: continuing to heat the debinded target material blank up to a first sintering temperature at a first heating rate in a gas environment for sintering, then continuing to heat the debinded target material blank up to a second sintering temperature at a second heating rate for sintering
Data Source
AI summary
The present disclosure to an oxide target material and a preparation method thereof. The oxide target material includes an oxide of an element A, an oxide of an element B, an oxide of an element R, and an oxide of an element M, wherein the element A is indium; the element B is selected from the group consisting of gallium, zinc, and tin, or a combination of two or more thereof; the element R is selected from the group consisting of cerium, praseodymium, ytterbium, dysprosium, and terbium, or a combination of two or more thereof; and the element M is selected from the group consisting of scandium, silicon, titanium, tantalum, germanium, and antimony, or a combination of two or more thereof. The present disclosure refines a grain size of the oxide target material by introducing the oxide of the element M into the oxide target material.