Silicon Part Etching via Peripheral Oxide Bead Mask
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing manufacturing method for silicon mechanical parts results in a significant percentage of peripheral parts being rejected due to oblique flanks caused by inhomogeneities in the plasma etch, leading to premature wear and contamination issues from resin residue.
Innovation Solution
A method involving the formation of a uniform bead of a second material at the substrate periphery, which acts as a mask during etching, ensuring a homogeneous plasma etch and preventing resin contamination, by depositing a nitride layer, oxidizing it selectively, and structuring it to extend to the periphery, allowing for directional etching without resin removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If resin removal operation is performed to prevent contamination, then contamination is reduced, but manufacturing complexity and time increase
Solution Approach 1:
The method performs preliminary structuring of the oxide layer to create a peripheral zone with controlled thickness before the etching step. This preliminary action ensures that the periphery is properly prepared to receive plasma etching without requiring subsequent resin removal operations, thus preventing contamination while avoiding additional manufacturing steps.
Solution Approach 2:
The invention extracts the problematic resin removal step from the manufacturing process by instead creating a structurally sound peripheral zone through selective oxide structuring. This allows the process to proceed without resin removal while achieving the same contamination prevention goal through a different mechanism.
2Device complexity
If standard photolithography is used without peripheral oxide structuring, then process simplicity is maintained, but plasma etch inhomogeneity occurs causing oblique flanks
Solution Approach 1:
The invention applies local quality by creating a peripheral zone with different oxide thickness characteristics compared to the central zone. The peripheral zone is structured to have reduced oxide thickness, which locally modifies the plasma etching behavior at the edges, ensuring uniform etching rates and perpendicular flanks across the entire wafer surface.
Solution Approach 2:
The method changes the physical parameter of oxide layer thickness in the peripheral zone through selective structuring. By modifying the oxide thickness parameter locally at the periphery before etching, the process achieves homogeneous plasma distribution and consistent etching rates, resulting in precise perpendicular flanks without complicating the overall process flow.
3Productivity
If peripheral parts are manufactured with standard processes, then production volume is maximized, but peripheral parts are rejected due to oblique flanks
Solution Approach 1:
The invention performs preliminary structuring of the peripheral oxide layer before the etching process, creating optimal conditions for uniform plasma etching across the entire wafer including peripheral regions. This preliminary action ensures that peripheral parts achieve the same quality standards as central parts, eliminating rejection reasons and maximizing usable production volume from each wafer.
Solution Approach 2:
By changing the oxide thickness parameter in the peripheral zone through selective structuring, the method creates uniform etching conditions across the entire wafer surface. This parameter modification ensures that peripheral parts are etched with the same precision as central parts, allowing all parts to meet quality specifications and be included in the final production output.
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 approach eliminates the rejection of peripheral parts by ensuring perpendicular flanks and reduces contamination, thereby improving the manufacturing efficiency and quality of silicon mechanical parts.
Implementation Method 1
oxidizing it selectively
Implementation Method 2
directional etching
Data Source
AI summary
A method of manufacturing parts of a first material able to be etched from a substrate including at least one superficial layer of the first material, includes (a) forming a substantially uniform superficial layer of a second material at the surface of the superficial layer of the first material, wherein the second material resists a selective etch of the first material, (b) forming a bead of second material at the periphery of the superficial layer of second material, (c) structuring the layer of second material and the bead by a photolithographic process including an etch step of sufficient duration to etch the superficial layer of second material over the entire thickness thereof, but insufficient to etch the bead over the entire thickness thereof, so as to obtain a mask, and (d) cutting out parts made of the first material through the mask of the second material, by directional etching.