Sputtering Target Fabrication via Single-Step Mixing
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Solution Overview
Problem
The existing methods for forming sputtering targets, particularly for high-K dielectric materials like BST, face challenges such as blistering, uneven dopant distribution, and low density, leading to suboptimal film quality and deposition rates due to the hot-press process limitations and contamination issues during mechanical mixing.
Innovation Solution
A method involving a single mixing step of major and minor constituents with specific thermal decomposition properties, followed by calcination and hot-pressing, to achieve a compositionally uniform and dense sputtering target with improved grain size distribution and reduced contamination, enabling higher deposition rates and increased target density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional two-step mixing and hot-pressing is used, then target formation is achieved, but blistering occurs and dopant distribution becomes uneven
Solution Approach 1:
The patent combines multiple mixing steps into a single optimized mixing process, integrating dopant incorporation with the main mixing operation. This unified approach ensures uniform dopant distribution throughout the target material while eliminating the blistering issues that arise from separate mixing and pressing operations.
Solution Approach 2:
The patent modifies key process parameters including mixing time, temperature, pressure, and atmosphere conditions to optimize both dopant distribution and target density. By carefully controlling these parameters in a single integrated process, the method achieves uniform dopant incorporation without causing blistering.
2Manufacturing precision
If longer mechanical mixing is used to improve dopant distribution, then uniformity improves, but micro-contamination increases from worn contacting parts
Solution Approach 1:
The patent employs disposable mixing media or liners that are discarded after a single use, eliminating the accumulation of micro-contamination from repeated use of mechanical mixing components. This approach maintains clean target material while achieving sufficient dopant distribution uniformity through optimized mixing parameters.
Solution Approach 2:
The patent introduces an intermediary substance or medium that facilitates dopant mixing without direct contact between the mechanical mixing components and the target material. This intermediary layer prevents micro-contamination from worn contacting parts while still enabling uniform dopant distribution through the mixing process.
3Reliability
If hot-press optimization is applied to reduce blistering, then target quality improves, but grain size distribution becomes too high and density decreases
Solution Approach 1:
The patent optimizes hot-pressing parameters including temperature, pressure, and time to achieve a balance between blistering prevention and grain size control. By carefully adjusting these parameters, the method produces targets with high density and fine grain size distribution while eliminating blistering defects.
Solution Approach 2:
The patent performs preliminary preparation of the green compact before hot-pressing, including optimized mixing and binding, to ensure uniform dopant distribution and appropriate green strength. This preliminary action allows for more effective hot-pressing with better control over grain size and density while preventing blistering.
4Productivity
If higher power is applied to increase deposition rate, then productivity improves, but target density must be sufficiently high to withstand the power
Solution Approach 1:
The patent produces targets with optimized density and microstructure through controlled processing parameters, enabling these targets to withstand higher power loads during sputtering. The improved target quality, achieved through single-step mixing and optimized hot-pressing, allows for increased power application and consequently higher deposition rates.
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
This approach results in sputtering targets with densities above 99% of theoretical density, allowing for higher power application and increased deposition rates, enhancing productivity and reducing manufacturing costs while maintaining film quality and uniformity.
Implementation Method 1
The sputtering process is utilizing cathode plasma discharge in vacuum resulting in the material transfer from the target to a substrate
Implementation Method 2
physical vapor deposition (PVD) from a target of the desired material, otherwise known as sputtering
Implementation Method 3
The precursors can be selected based on thermal decomposition properties of the components
Data Source
AI summary
A system that incorporates teachings of the subject disclosure may include, for example, a method in which a selection is made for a first major constituent, a second major constituent and a minor constituent for forming a desired material. The method can include mixing the first major constituent, the second major constituent and the minor constituent in a single mixing step to provide a mixture of constituents. The method can include drying the mixture of constituents to provide a dried mixture of constituents and calcining the dried mixture of constituents to provide a calcinated mixture of constituents. The method can include processing the calcinated mixture of constituents to provide a powder of constituents. Other embodiments are disclosed.