Wavelike Hard Nanomask Ion Sputtering Alignment
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Solution Overview
Problem
Conventional methods for forming periodic nanoline patterns on semiconductor surfaces often result in defects such as line bends, breaks, and joints, which hinder their application in semiconductor microelectronics and optoelectronics due to lack of desired coherency and alignment.
Innovation Solution
A method involving the use of a hard nanomask with a wavelike cross-section, formed by irradiating a layer of material with an ion flow, is employed to transfer a substantially periodic pattern onto a thin film. This nanomask includes parallel, elongated elements with specific cross-sectional structures, positioned on lithographically defined topographic features, and is formed using ion sputtering techniques with controlled ion incidence angles and stepwise irradiation to enhance pattern coherency and alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If self-formation phenomena are used to form periodic nanoline patterns, then the formation process is simplified, but defects such as line bends, breaks, and joints are inherent and reduce pattern quality
Solution Approach 1:
The patent divides the pattern formation process into two distinct stages: first forming a wavelike nanomask structure through ion beam irradiation, then using this mask to transfer the pattern onto the target film. This segmentation allows each stage to be optimized independently, achieving both ease of manufacture and high precision.
Solution Approach 2:
The patent performs preliminary action by first creating the wavelike nanomask structure on the surface before transferring the pattern. This pre-formed mask serves as a template that guides subsequent pattern transfer, ensuring high coherency and alignment while simplifying the overall manufacturing process.
2Ease of manufacture
If conventional ion incidence angles (42° to 55°) are used for forming WOS structures, then the formation process is straightforward, but the pattern quality and alignment with topographic features are insufficient
Solution Approach 1:
The patent changes the ion incidence angle parameter from conventional values (42° to 55°) to a specific range of 65° to 75° relative to the surface normal. This parameter change fundamentally alters the ion-surface interaction, enabling formation of wavelike structures with superior alignment to topographic features and higher pattern quality.
Solution Approach 2:
The patent achieves local quality by creating regions of different nanomask thickness corresponding to different parts of the topographic feature. The ion irradiation produces varying mask densities and thicknesses that are optimally suited for different local areas, improving overall pattern alignment and quality.
3Ease of manufacture
If ion sputtering is used to form the nanomask, then periodic patterns can be created, but the topographic feature narrows due to sputtering material removal
Solution Approach 1:
The patent applies preliminary anti-action by depositing additional material onto the topographic feature before ion sputtering to compensate for the material removal. This pre-compensation ensures that the feature width is maintained despite the sputtering process, allowing nanomask formation without narrowing.
Solution Approach 2:
The patent uses composite materials by combining the original topographic feature material with additional deposited material. This composite structure provides both the necessary width maintenance and the appropriate surface properties for effective ion sputtering and nanomask formation.
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 method significantly improves the coherency and straightness of the nanoline patterns, making them suitable for semiconductor microelectronics and optoelectronic applications by reducing defects and ensuring proper alignment with the surface features.
Implementation Method 1
formed by modifying the first material using an ion flow
Implementation Method 2
irradiating a layer of a first material with an ion flow
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3A~3C
AI summary
An array of nanowires with a period smaller than 150 nm can be used for optoelectronics and semiconductor electronics applications. A hard nanomask is registered to a lithographically defined feature and can be used to manufacture such structures. This nanomask includes a substantially periodic array of substantially parallel elongated elements having a wavelike cross-section. The fabrication method of the nanomask may be contactless and uses ion beams.