In-Vacuum Shadow Mask Repositioning for Oxidation-Free Deposition
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Solution Overview
Problem
The existing methods for fabricating microscale and nanoscale devices, such as semiconductor and quantum computing devices, face challenges in maintaining ideal interfaces between materials due to the need to break vacuum and expose wafers to air, leading to oxidation and disruption of the fabrication process.
Innovation Solution
A method is developed to manipulate shadow masks in-situ within a vacuum chamber, allowing for continuous vacuum conditions during multiple stages of deposition by using a mask-handling mechanism with sensors and actuators for precise repositioning and alignment, eliminating the need to break vacuum and reducing oxidation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional lithography with photo resist is used to form patterns, then pattern definition is achieved, but multiple vacuum breaks and re-evacuations are required between deposition steps
Solution Approach 1:
The patent extracts the masking function from the photo resist process and implements it using a separate shadow mask component that can be positioned and repositioned within the vacuum chamber. This allows the mask to be removed and replaced without breaking vacuum, eliminating the time loss associated with vacuum breaks while maintaining precise pattern definition through the shadow mask's perforated structure
Solution Approach 2:
The patent introduces dynamic mask positioning capabilities where the shadow mask can be moved between different positions and orientations within the vacuum chamber using a mask holder mechanism. This dynamic repositioning allows multiple deposition patterns to be created with a single mask without requiring vacuum breaks, thereby reducing time loss while maintaining manufacturing precision
2Adaptability or versatility
If the wafer is removed from the vacuum chamber for mask replacement, then mask changes are possible, but oxidation occurs on the wafer surface
Solution Approach 1:
The patent maintains the vacuum chamber's vacuum environment (inert atmosphere) throughout the entire process by providing mask replacement and repositioning mechanisms that operate within the vacuum. The mask holder and positioning system allow masks to be changed and adjusted without exposing the wafer to air, thereby preventing oxidation while maintaining adaptability for different deposition patterns
Solution Approach 2:
The patent introduces a mask holder as an intermediary component that interfaces between the mask and the vacuum chamber environment. This holder allows masks to be installed, removed, and repositioned without direct exposure of the wafer to external air, serving as a mediator that enables mask versatility while protecting the wafer from oxidation
3Device complexity
If multiple lithography steps are performed with vacuum breaks, then complex multi-layer structures can be formed, but interface quality deteriorates
Solution Approach 1:
The patent enables continuous deposition operations by maintaining the vacuum environment throughout multiple deposition steps. The shadow mask system allows different patterns to be deposited sequentially without breaking vacuum, ensuring continuous useful action that prevents oxidation and maintains ideal interfaces between layers while achieving complex multi-layer structures
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 enables high-quality, multi-layered structures to be fabricated without disrupting the vacuum, maintaining interface quality and preventing oxidation, which is crucial for nanoscale devices like quantum electronics and optics.
Implementation Method 1
a shadow mask is deployed over the wafer in the vacuum chamber. Following the deployment of the shadow mask, a first fabrication step is performed which comprises projecting material onto the wafer through patterned openings in the shadow mask
Implementation Method 2
a mask-handling mechanism is operated in order to reposition the shadow mask to a second location within the vacuum chamber. The repositioning comprises receiving readings from one or more sensors sensing a current location of the shadow mask and based thereon aligning the current location of the shadow mask to the second location
Data Source
AI summary
A method of fabrication in a vacuum chamber. The method comprises: deploying the wafer within the vacuum chamber; applying a mask in a first position over the wafer in the vacuum chamber; following this, performing a first fabrication step comprising projecting material onto the wafer through the mask while in vacuum in the vacuum chamber; then operating a mask-handling mechanism deployed within the vacuum chamber in order to reposition the mask to a second position while remaining in vacuum in the vacuum chamber, wherein the repositioning comprises receiving readings from one or more sensors sensing a current position of the mask and based thereon aligning the current position of the mask to the second position; and following this repositioning, performing a second fabrication step comprising projecting material onto the wafer through patterned openings in the repositioned mask while still maintaining the vacuum in the vacuum chamber.