Variable Interference Filter Deposition With Static Sputtering Masks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing high-performance linear variable interference filters are limited by low throughput, high costs, and imprecise spatial grading due to the need for precise control of thin film deposition processes, particularly at room temperature, which is challenging with existing techniques like electron beam deposition and ion beam sputtering.
Innovation Solution
A vacuum chamber setup with a magnetron sputtering device and a static sputtering mask is used to deposit layers of varying thickness on substrates, allowing for the creation of variable interference filters with non-uniform thicknesses, enabling the production of high-resolution filters with improved throughput and precision at room temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If electron beam deposition or ion beam sputter deposition is used to produce high-performance LVFs, then manufacturing precision is improved, but productivity is reduced due to low throughput and complex setup
Solution Approach 1:
The patent changes the deposition method from electron beam or ion beam sputtering to magnetron sputtering, which operates at room temperature with higher deposition rates. This parameter change maintains layer thickness control while significantly improving throughput and reducing manufacturing time
Solution Approach 2:
The patent replaces the complex electron beam or ion beam sputtering systems with a simpler magnetron sputtering system. This substitution eliminates the need for extensive heating-up and cooling-down periods while maintaining precise deposition control through the magnetron's inherent plasma confinement
2Manufacturing precision
If dynamic uniformity masking is used to produce variable interference filters, then spectral properties are improved, but productivity is reduced due to difficult control and imprecise spatial grading
Solution Approach 1:
Instead of using dynamic masking to create uniformity, the patent inverts the approach by using a static mask with a specific geometry (angled or curved surface) that passively creates the desired non-uniform thickness profile. This inversion eliminates the complexity of dynamic control while achieving precise spatial grading
Solution Approach 2:
The patent performs preliminary action by pre-configuring the static mask with the appropriate geometry before deposition begins. The mask's shape is designed in advance to produce the desired thickness variation pattern, eliminating the need for real-time dynamic adjustments during the deposition process
3Manufacturing precision
If ion beam sputtering is used to deposit layers, then manufacturing precision is improved, but productivity is reduced due to intrinsically low deposition rates
Solution Approach 1:
The patent substitutes ion beam sputtering with magnetron sputtering, which uses a magnetically confined plasma to achieve higher deposition rates. The magnetron's rotating magnetic field creates a concentrated plasma region that delivers material to the substrate more efficiently while maintaining good thickness control
Solution Approach 2:
The patent changes the deposition parameters by operating at room temperature with magnetron sputtering instead of the typically lower temperatures used in ion beam sputtering. This parameter change increases the deposition rate while the magnetron's inherent plasma confinement maintains sufficient layer quality
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 method enables the efficient and precise deposition of variable interference filters with non-uniform thicknesses, enhancing their spectral properties and manufacturing efficiency, suitable for applications in multispectral and hyperspectral imaging and sensing.
Implementation Method 1
The at least one magnetron sputtering device is configured to sputter (i.e. in use) material from a sputtering target towards the mount, thereby defining a sputtering zone within the vacuum chamber
Implementation Method 2
At least one static sputtering mask is located between the sputtering target and the mount, the at least one static sputtering mask being configured (e.g. shaped) such that (i.e. in use), when each substrate is moved through the sputtering zone on the at least one movable mount, a layer of (i.e. sputtered) material having a non-uniform thickness is deposited on each said substrate
Implementation Method 3
Interference filters typically selectively transmit or reflect incident light in one or more spectral bands, the characteristic wavelengths of the bands being determined by Fabry-Pérot interference between rays of light partially reflected and partially transmitted at two or more interfaces within the said interference filter
Data Source
AI summary
Apparatus for depositing one or more variable interference filters onto one or more substrates comprises a vacuum chamber, at least one magnetron sputtering device and at least one movable mount for supporting the one or more substrates within the vacuum chamber. The at least one magnetron sputtering device is configured to sputter material from a sputtering target towards in the mount, thereby defining a sputtering zone within the vacuum chamber. At least one static sputtering mask is located between the sputtering target and the mount. The at least one static sputtering mask is configured such that, when each substrate is moved through the sputtering zone on the at least one movable mount, a layer of material having a non-uniform thickness is deposited on each said substrate.