Sputtering Apparatus Lateral Gun Offset Contamination
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Solution Overview
Problem
Existing sputtering apparatuses for magnetic memory devices face challenges in minimizing substrate contamination during the sputtering process, which affects the reliability and quality of the deposited thin layers.
Innovation Solution
A sputtering apparatus with multiple sputter guns positioned non-overlappingly with respect to the substrate, using a shutter to protect the substrate from detached sputtering sources, and employing RF sputtering with metal oxide targets to form magnetic tunnel junctions, ensuring contamination reduction and enhanced deposition rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a sputter gun is positioned vertically overlapping with the substrate to maximize deposition efficiency, then the deposition rate is improved, but the substrate becomes contaminated by detached sputtering sources
Solution Approach 1:
The sputter gun is repositioned from a vertical alignment (one-dimensional overlap) to a lateral offset position (two-dimensional separation). By spacing the sputter gun horizontally away from the substrate while maintaining vertical deposition capability, the patent eliminates direct contamination paths while preserving deposition efficiency through angled or distributed material flux.
Solution Approach 2:
A shutter is introduced as an intermediary component between the sputter gun and substrate. The shutter physically blocks detached sputtering sources from reaching the substrate surface while allowing the sputtering process to continue. This mediator protects the substrate without requiring changes to the fundamental sputter gun positioning or deposition mechanism.
2Object-affected harmful factors
If the sputter gun is spaced far from the substrate to avoid contamination, then substrate contamination is reduced, but the deposition rate decreases
Solution Approach 1:
Instead of increasing vertical spacing (which reduces deposition rate), the patent utilizes horizontal spacing to achieve contamination reduction. By moving the sputter gun laterally offset from the substrate center, the patent maintains optimal vertical distance for high deposition rate while creating horizontal separation that prevents contaminant accumulation on the substrate surface.
Solution Approach 2:
The deposition process is segmented into multiple zones using laterally offset sputter guns. Each sputter gun deposits material from a specific angular direction, creating distributed deposition zones that cover the substrate without requiring direct vertical overlap. This segmentation allows each gun to operate at optimal distance while collectively achieving uniform coverage with minimal contamination.
3Productivity
If multiple sputter guns are used to increase deposition rate, then productivity is improved, but the complexity of the apparatus increases
Solution Approach 1:
Multiple sputter guns are merged into a coordinated system with standardized mounting and control. The guns are positioned at symmetric lateral offsets and operated simultaneously or sequentially under unified control, combining their deposition fluxes to achieve high deposition rates. This merging approach distributes the contamination risk across multiple sources while maintaining systematic simplicity through standardized configuration.
Solution Approach 2:
The laterally offset sputter gun configuration serves multiple functions simultaneously: it enables high deposition rates through parallel operation, prevents substrate contamination through horizontal spacing, and allows flexible patterning through selective gun activation. This universal configuration replaces the need for complex contamination control mechanisms with a single geometric solution that addresses multiple requirements.
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 effectively inhibits substrate contamination, improves the reliability of magnetic memory devices by maintaining a clean deposition environment and increasing the deposition rate of non-magnetic layers, facilitating mass production with improved magnetic tunnel junction formation.
Implementation Method 1
The insulating layer included in the magnetic tunnel junction pattern may be deposited using a sputtering process
Implementation Method 2
employing RF sputtering with metal oxide targets to form magnetic tunnel junctions
Data Source
AI summary
A sputtering apparatus includes a process chamber in which a sputtering process is performed, a substrate holder provided in the process chamber and fixing a horizontal position of a substrate during the sputtering process, and a first sputter gun provided to be vertically spaced apart from the substrate in the process chamber. The first sputter gun is spaced apart from the substrate by a first horizontal distance during the sputtering process. The first sputter gun is fixed during the sputtering process. The first horizontal distance is a horizontal distance between the substrate and the first sputter gun when viewed from a plan view.