Elevated MEMS Scanning Mirror Assembly for Optical Fill Factor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional MEMS mirror assemblies have a less than optimal optical fill factor due to the MEMS actuator occupying a portion of the mirror surface, limiting the reflective surface area and optical efficiency.
Innovation Solution
The scanning mirror assembly is designed with the scanning mirror in a first layer elevated above a MEMS actuator in a second layer, formed from the same semiconductor layer, which increases the fill factor and mitigates misalignment issues by forming interdigitated stator and rotatable actuator features in the same layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the MEMS actuator is formed in the same layer as the mirror, then the manufacturing process is simplified, but the optical fill factor is reduced due to the actuator occupying mirror surface area
Solution Approach 1:
The patent transitions from a planar, single-layer arrangement to a three-dimensional, multi-layer structure. The mirror is positioned in an upper layer while the actuator is positioned in a lower layer, utilizing the vertical dimension to resolve the spatial conflict between the actuator and mirror surfaces. This allows both components to coexist without occupying the same surface area, thereby improving the optical fill factor while maintaining manufacturing feasibility through established multi-layer semiconductor fabrication processes.
2Stability of the object's composition
If the comb drive fingers are included in the same layer as the mirror, then the structural integration is improved, but the optical efficiency is reduced due to the fingers not being part of the reflecting area
Solution Approach 1:
The patent segments the device into distinct functional layers: the upper layer contains only the mirror structure optimized for optical reflection, while the lower layer contains the actuator features including comb drive fingers optimized for mechanical actuation. This segmentation allows each component to be optimized independently for its specific function without compromising the other, thereby improving overall optical efficiency while maintaining structural integration through precise vertical alignment and coupling between layers.
Data Source
AI summary
Embodiments of the disclosure include a scanning mirror assembly for an optical sensing system. The scanning mirror assembly may include a scanning mirror formed in a first layer of the scanning mirror assembly. The scanning mirror assembly may also include a MEMS actuator formed in a second layer of the scanning mirror assembly, where the first layer is a predetermined distance above the second layer. The MEMS actuator may also include a plurality of stator actuator features and a plurality of rotatable actuator features formed from a same semiconductor layer during a fabrication process.