NiW Sputtering Target Crack-Free Thermal Spraying
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Solution Overview
Problem
Existing NiW sputtering targets face issues with cracking and arcing due to segmented structures and high oxygen introduction, limiting their thickness and length, which results in reduced target life and increased production costs.
Innovation Solution
A NiW sputtering target with a normalized peak intensity ratio of 0.40 or greater, manufactured using improved thermal spraying conditions, allowing for increased thickness and length without bond gaps or cracking, achieved by optimizing the deposition process with specific metal ratios and powder characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If thermal spraying process is used to manufacture NiW sputtering targets, then production cost is reduced and manufacturing efficiency is improved, but cracks occur in the target material layer when thickness exceeds 3-4 mm
Solution Approach 1:
The patent applies parameter changes by optimizing the thermal spraying process parameters including powder feed rate (10-30 g/min), plasma gas flow rates (20-40 L/min for primary gas, 10-20 L/min for secondary gas), and maintaining substrate temperature below 100°C. These parameter adjustments control the deposition rate and thermal history to prevent crack formation while achieving thicknesses exceeding 5 mm.
Solution Approach 2:
The patent employs periodic action through pulsed or intermittent spraying cycles, where the spraying process is applied in controlled intervals rather than continuously. This allows thermal management during deposition, preventing excessive heat accumulation that would cause cracking in thick layers while maintaining manufacturing efficiency.
2Strength
If HIP process is used to manufacture NiW sputtering targets, then target integrity is improved and cracks are prevented, but production cost increases and manufacturing complexity increases
Solution Approach 1:
The patent replaces the mechanical HIP pressing system with a thermal spraying deposition system. Instead of consolidating powder through high-pressure isostatic pressing, the invention directly deposits NiW material layers through controlled thermal spraying, achieving both integrity and cost-effectiveness in a single manufacturing step.
3Duration of action of stationary object
If target thickness is increased to extend target life, then target longevity is improved, but cracks occur in conventionally manufactured targets limiting maximum thickness to 3-4 mm
Solution Approach 1:
The patent uses parameter changes in the thermal spraying process, specifically controlling deposition rate, plasma power, and substrate temperature to enable crack-free deposition of thick layers. The substrate temperature is maintained below 100°C and deposition rates are optimized to manage thermal stress, allowing target thicknesses exceeding 5 mm without cracking.
Solution Approach 2:
The patent applies preliminary action by preparing the substrate surface and optimizing the spraying parameters before actual deposition. The substrate is pre-treated and the spraying conditions are pre-established to ensure uniform stress distribution during thick layer deposition, preventing crack initiation from the outset.
4Length of stationary object
If segmented target structure is used to achieve longer target length, then manufacturing feasibility is improved, but bond gaps cause re-deposits and arcing risk during reactive sputtering
Solution Approach 1:
The patent applies segmentation by manufacturing the target in manageable sections that are subsequently joined. The thermal spraying process deposits material in controlled passes, and the resulting target can be divided into segments that are bonded together, achieving long target lengths while maintaining integrity through controlled joining rather than relying on continuous deposition that would cause bonding issues.
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 solution enables the production of crack-free NiW sputtering targets with increased thickness and length, reducing arcing risks and production costs, while maintaining target performance and longevity.
Implementation Method 1
A possible further manufacturing technology for NiW(X) targets is plasma spraying of elemental powder blends
Implementation Method 2
the intensities of the peaks are determined by X-ray powder diffraction using Cu-Kalpha radiation
Implementation Method 3
the intensities of the peaks are determined by X-ray powder diffraction
Data Source
AI summary
The present invention relates to a sputtering target comprising Ni, W and, optionally, one or more further metal(s) X selected from the group of the refractory metals, Sn, Al and Si, which has a normalized peak intensity ratioPIR=INi/IW·(AW+Ax)/ANi of 0.40 or greater, whereinINi is the intensity of the (111) peak of Ni,IW is the intensity of the (110) peak of W,Aw is the fraction of W in the target in atom %,Ax is the total fraction of the one or more further metals selected from the group of the refractory metals, Sn, Al and Si in the target in atom %,ANi is the fraction of Ni in the target in atom %,and wherein the intensities of the peaks are determined by X-ray powder diffraction using Cu-Kalpha radiation.