Optical Diffuser Fabrication with Sacrificial Silicon Layers
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Solution Overview
Problem
Existing methods for manufacturing optical diffusers, such as etching on glass or using polymer materials, are complex, costly, and require specialized equipment, making them incompatible with conventional microelectronic component manufacturing processes.
Innovation Solution
A method involving a silicon wafer with selectively etchable layers, where openings are formed and filled with specific materials, followed by bonding a glass substrate and removing the silicon slice, allowing for the use of conventional microelectronic manufacturing equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If conventional glass etching or polymer nanoprinting methods are used to manufacture optical diffusers, then organic-shaped diffusing patterns can be achieved, but the manufacturing process becomes complex and requires specialized equipment
Solution Approach 1:
The patent introduces a silicon-based intermediate structure with sacrificial layers that mediates between the desired organic diffuser shape and conventional semiconductor manufacturing capabilities. The silicon wafer with patterned sacrificial layers serves as a temporary substrate that enables precise pattern transfer using standard equipment, resolving the contradiction between achieving complex organic shapes and maintaining manufacturing simplicity.
Solution Approach 2:
The patent changes the material parameter from traditional glass or polymer to silicon-based materials with controlled sacrificial layers. This parameter change allows the use of established semiconductor fabrication techniques (deposition, etching, bonding) to create organic diffuser patterns, thereby reducing manufacturing complexity while maintaining shape precision.
2Manufacturing precision
If specialized glass etching techniques are used, then optical diffusers with precise dimensions can be manufactured, but the cost increases and compatibility with conventional microelectronic manufacturing is lost
Solution Approach 1:
The patent makes the manufacturing process universal by adapting optical diffuser fabrication to use the same conventional semiconductor manufacturing equipment already widely available in the industry. The process leverages multi-functional equipment capabilities (deposition chambers, etchers, bonders) already present in microelectronic fabs, eliminating the need for specialized glass processing equipment and reducing manufacturing costs while maintaining precision.
Solution Approach 2:
The patent employs disposable sacrificial silicon layers that are deposited precisely, patterned, and then completely removed after serving their temporary purpose of defining the diffuser pattern geometry. These sacrificial layers enable precise pattern formation using low-cost conventional equipment, and their temporary nature allows for precise dimension control without requiring expensive specialized processing equipment.
3Ease of manufacture
If polymer materials are used for nanoprinting or molding, then diffusing patterns can be formed, but the polymer material may pose problems for certain applications
Solution Approach 1:
The patent uses composite material structures combining silicon-based sacrificial layers with glass substrate materials. This composite approach allows the diffuser to be manufactured using inorganic materials that are compatible with a broader range of applications including high-temperature environments, harsh chemical conditions, and optical applications requiring specific refractive index properties, while still maintaining ease of manufacture through conventional semiconductor processes.
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
Enables the production of optical diffusers with precise dimensions and organic shapes using conventional silicon-based manufacturing techniques, reducing complexity and cost while maintaining optical performance.
Implementation Method 1
a second layer made of a second selectively etchable material with respect to the first material
Implementation Method 2
the third material is selectively etchable with respect to the second material
Implementation Method 3
bonding a glass substrate to the wafer on the side of its upper face
Implementation Method 4
removing the silicon slice
Data Source
AI summary
Methods of manufacture of an optical diffuser. In one embodiment, an optical diffuser is formed by providing a wafer including a silicon slice of which an upper face is covered with a first layer made of a first material itself covered with a second layer made of a second selectively etchable material with respect to the first material. The method further includes forming openings in the second layer extending up to the first layer and filling the openings in the second layer with a third material. The method yet further includes bonding a glass substrate to the wafer on the side of its upper face and removing the silicon slice.