Mirror Device Manufacturing With Wafer Circulation Holes for Wet Cleaning
Solution Overview
Problem
The manufacturing method for mirror devices risks damaging the movable portions due to the load of cleaning liquids and allows foreign substances to remain, which can be exacerbated by reducing the intensity of cleaning to mitigate damage.
Innovation Solution
A method involving etching to form circulation holes in the wafer at parts other than the slit, allowing cleaning liquid circulation during wet cleaning to reduce the load on movable portions and facilitate foreign substance removal, while also forming a mirror layer and using protective film and patterning member removal processes to minimize damage and residue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the wafer is cleaned using a cleaning liquid after the movable portion is released, then foreign substances can be removed from the wafer, but the movable portions may be damaged due to the load of the cleaning liquid
Solution Approach 1:
The wafer is divided into multiple parts by forming slits and circulation holes, allowing the cleaning liquid to flow through specific pathways (circulation holes) rather than directly impacting the movable portions. This segmentation of the cleaning process reduces the load on movable portions while maintaining cleaning effectiveness in other regions.
Solution Approach 2:
Circulation holes are introduced as intermediary structures that channel the cleaning liquid away from the movable portions. These holes act as mediators between the cleaning liquid and the wafer surface, directing the liquid flow to clean areas while protecting the movable portions from direct contact and damage.
2Reliability
If the intensity of cleaning using a cleaning liquid is weakened to reduce damage to movable portions, then the load on movable portions is reduced, but foreign substances may remain in the wafer
Solution Approach 1:
Different regions of the wafer are treated differently during cleaning. The circulation holes are positioned in specific locations to direct cleaning liquid flow to areas that need cleaning while avoiding the movable portions. This local differentiation allows intensive cleaning in certain regions without compromising the movable portions.
Solution Approach 2:
The wafer structure is segmented into cleaning zones and protected zones through the strategic placement of circulation holes and slits. This segmentation enables the cleaning process to be intensified in regions where it is safe to do so while maintaining protection for the movable portions, thus achieving both thorough cleaning and component integrity.
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 effectively reduces damage to mirror devices and ensures thorough cleaning by minimizing the load on movable portions and removing foreign substances, thereby enhancing the manufacturing process's reliability and quality.
Implementation Method 1
a third step of performing wet cleaning for cleaning the wafer using a cleaning liquid after the second step
Implementation Method 2
a second step of forming a slit in the wafer such that the movable portion becomes movable with respect to the base portion by removing a part of each of the support layer and the device layer from the wafer by etching
Data Source
AI summary
A method for manufacturing a mirror device, the method includes a first step of preparing a wafer having a support layer and a device layer; a second step of forming a slit in the wafer such that the movable portion becomes movable with respect to the base portion by removing a part of each of the support layer and the device layer from the wafer by etching and forming a plurality of parts each corresponding to the structure in the wafer, after the first step; a third step of performing wet cleaning for cleaning the wafer using a cleaning liquid after the second step; and a fourth step of cutting out each of the plurality of parts from the wafer after the third step. In the second step, a circulation hole penetrating the wafer is formed at a part other than the slit in the wafer by the etching.