Tantalum Sputtering Target Crystal Orientation Control
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Solution Overview
Problem
Current sputtering targets require lengthy burn-in times and fluctuating deposition speeds, leading to inefficiencies and increased production costs in semiconductor manufacturing, due to uncontrolled processing strain and residual stress.
Innovation Solution
A tantalum or tantalum-based alloy sputtering target with a controlled FWHM of the {200} crystal plane, ranging from 0.1 to 0.6°, achieved through deformation processing and heat treatment, to minimize processing strain and stabilize deposition speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If conventional sputtering targets are used with uncontrolled processing strain, then manufacturing is simpler, but burn-in time is lengthy and deposition speed fluctuates
Solution Approach 1:
The patent applies preliminary action by performing deformation processing and heat treatment during target manufacturing to pre-establish the desired crystal grain structure and minimize processing strain before the sputtering process begins. This preliminary preparation reduces the burn-in time required during actual sputtering operations, as the target is already in an optimized state for stable deposition.
Solution Approach 2:
The patent employs parameter changes by controlling specific parameters during deformation processing and heat treatment, including temperature ranges, deformation degrees, and heat treatment durations. These parameter adjustments optimize the crystal grain size and orientation, thereby minimizing processing strain and reducing the burn-in time while maintaining manufacturing feasibility.
2Reliability
If deformation processing and heat treatment are applied to control crystal grain structure, then deposition speed stability improves, but manufacturing process complexity increases
Solution Approach 1:
The patent utilizes parameter changes by defining specific ranges for deformation processing parameters (deformation degree, temperature) and heat treatment parameters (temperature range, duration). By optimizing these parameters, the crystal grain structure is controlled to ensure stable deposition speed, while the parameter ranges are set to maintain practical manufacturability.
Solution Approach 2:
The patent applies local quality by focusing the deformation processing and heat treatment on specific regions or aspects of the target material that most influence deposition stability. This targeted approach ensures that the critical areas have the desired crystal grain structure while minimizing the overall processing complexity.
3Manufacturing precision
If crystal grain size and orientation are controlled, then uniformity of film thickness and resistance improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs parameter changes by establishing specific ranges for crystal grain size (5-50 μm average) and orientation ({100}, {110}, or {111} preference) through controlled deformation and heat treatment. These parameter specifications achieve the desired film uniformity while remaining attainable through conventional metallurgical processing techniques.
Solution Approach 2:
The patent applies continuity of useful action by integrating the crystal grain control process as a continuous sequence of deformation processing followed by heat treatment, rather than separate discrete steps. This continuous approach ensures consistent crystal grain structure throughout the target material, improving film uniformity while streamlining the manufacturing process.
4Object-generated harmful factors
If surface roughness is reduced and work-affected layer is eliminated, then particle generation decreases, but processing time and material loss increase
Solution Approach 1:
The patent applies preliminary action by performing surface processing (lapping, polishing, mechano-chemical polishing) during target manufacturing to pre-establish a low roughness surface (Ra ≤ 0.5 μm) and minimize the work-affected layer thickness (≤ 50 μm). This preliminary surface preparation reduces particle generation during sputtering without requiring additional processing time during operation.
Solution Approach 2:
The patent employs parameter changes by optimizing the surface processing parameters including lapping grit size, polishing pressure, and mechano-chemical polishing conditions. These parameter adjustments achieve the target surface roughness (Ra ≤ 0.5 μm) and work-affected layer thickness (≤ 50 μm) while minimizing material removal and processing time.
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
Significantly reduces the initial burn-in time and deposition speed fluctuations, enhancing semiconductor production efficiency and reducing costs by stabilizing the sputtering process.
Implementation Method 1
The present invention relates to a sputtering target capable of shortening the burn-in time and performing deposition on a wafer or a substrate at a stable speed during sputtering.
Data Source
AI summary
Provided is a tantalum or a tantalum alloy target capable of shortening the burn-in time and minimizing the fluctuation in the deposition speed throughout the target life, whereby the production efficiency of semiconductors in the sputtering process can be improved and stabilized, and the production cost can be significantly reduced. With tantalum or tantalum-based alloy sputtering target, provided is a sputtering target, wherein FWHM (full width of half maximum) of a {200} crystal plane measured by X-ray diffraction of the sputtered outermost surface is 0.1 to 0.6°, and wherein the variation of FWHM is within ±0.05°.