Embedded Micro Lens Structures via Two-Step Substrate Etching
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Solution Overview
Problem
Existing micro lens formation methods using hard masks result in non-uniformity of micro lens size and shape due to thickness variations, leading to inconsistencies in optical signaling and processing applications.
Innovation Solution
A two-step etching process is employed to form micro lenses directly in a transparent substrate without using a hard mask, involving the formation of sacrificial blocks, reflowing, and subsequent etching to create recesses and embed the lenses, ensuring uniformity and precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If hard masks are used to form micro lenses, then the manufacturing process is simplified, but non-uniformity of micro lens size and shape occurs due to thickness variations
Solution Approach 1:
The patent removes the hard mask layer from the micro lens formation process. By extracting this intermediate layer, the invention eliminates the source of non-uniformity caused by hard mask thickness variations, while still achieving precise micro lens formation through direct pattern transfer to the lens material.
Solution Approach 2:
The patent employs preliminary patterning of the lens material itself before the etching process. By pre-forming the lens pattern on the substrate surface, the invention ensures uniform micro lens dimensions are established before any material removal occurs, eliminating downstream variations.
2Device complexity
If hard masks are used to form micro lenses, then the process structure is established, but inconsistencies in optical signaling performance result
Solution Approach 1:
The patent extracts and removes the hard mask step from the process structure. This simplification directly improves optical signaling consistency by eliminating the variable introduced by hard mask thickness variations, while the remaining process steps maintain necessary structural complexity through alternative patterning and etching sequences.
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 eliminates the need for hard masks, preventing non-uniformity issues and enhancing the consistency and performance of micro lenses in optical and electrical signaling applications.
Implementation Method 1
reflowing the sacrificial blocks
Implementation Method 2
performing a first etching process to etch both of the sacrificial blocks and the substrate
Data Source
AI summary
A method includes forming sacrificial blocks on a substrate, reflowing the sacrificial blocks, performing a first etching process to etch both of the sacrificial blocks and the substrate until parts of the substrate that are etched to form micro lenses, forming a patterned etching mask, and performing a second etching process to etch the substrate. At a time after both of the first etching process and the second etching process have been performed, the micro lenses are in recesses of the substrate.