Micro-structure Manufacturing via HF-Methanol Dry-Etching
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Solution Overview
Problem
The existing micro-structure manufacturing methods using dry-etching of a sacrificial layer on a silicon substrate face challenges with etching dispersion caused by H2O as a reaction product, which complicates the etching process and increases costs due to the need for complex structures to manage residual materials.
Innovation Solution
The method involves repetitively etching and removing H2O as a reaction product during the dry-etching process using a mixture of anhydrous HF gas and methanol, employing techniques such as evacuating, purging with dry inert gas, and varying pressure to suppress etching dispersion without requiring complex structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If dry-etching is performed using mixture gas of anhydrous HF gas and methanol gas, then the sacrificial layer can be etched effectively, but H2O is generated as a reaction product which causes etching dispersion
Solution Approach 1:
The patent extracts and removes H2O as the harmful reaction product from the etching chamber during the dry-etching process. By continuously evacuating and purging H2O from the chamber, the harmful effect of H2O on etching uniformity is eliminated while maintaining the high etching rate provided by the HF-methanol gas mixture
Solution Approach 2:
The patent implements periodic cycles of etching followed by evacuation and purging operations. During each cycle, the sacrificial layer is etched for a predetermined period, then the chamber is evacuated and purged to remove accumulated H2O before the next etching phase begins. This periodic removal of H2O prevents etching dispersion while maintaining productivity
2Manufacturing precision
If H2O is removed by evacuating and purging during the etching process, then etching dispersion is suppressed, but the process time increases
Solution Approach 1:
The patent applies partial removal of H2O rather than complete continuous removal. The evacuation and purging are performed for predetermined periods that are sufficient to reduce H2O concentration to acceptable levels without requiring excessive removal time. This partial action approach achieves etching uniformity while minimizing time loss
Solution Approach 2:
The patent performs preliminary evacuation and purging operations before the etching process begins and between etching cycles. By removing H2O in advance and between cycles, the harmful effects are prevented before they can cause significant etching dispersion, reducing the need for lengthy corrective measures
3Manufacturing precision
If complex structures such as etching stop layers are introduced to regulate etching region, then etching quality can be managed, but device complexity and cost increase
Solution Approach 1:
The patent makes the etching process self-regulating by continuously monitoring and removing H2O during the process. The system uses the reaction products themselves (H2O) as the control parameter, automatically adjusting the etching uniformity through evacuation and purging operations without requiring additional complex structural elements
Solution Approach 2:
The patent changes the process parameters by controlling the evacuation and purging conditions (pressure, gas flow rates, timing) to achieve uniform etching. By adjusting these operational parameters rather than modifying the physical structure, the patent achieves etching quality control without increasing device complexity
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 effectively reduces the impact of H2O on the etching process, allowing for improved etching control and suppression of etching dispersion, thereby enhancing the quality and consistency of micro-structure manufacturing without increasing costs.
Implementation Method 1
the sacrificial layer reacting with etching gas to generate reaction products containing H2O
Implementation Method 2
H2O is adsorbed to the silicon substrate again
Implementation Method 3
a method of using etching gas such as HF (hydrogen fluoride) gas or the like has been proposed as a micro-structure manufacturing method for forming a structure by dry-etching
Data Source
AI summary
A method of manufacturing a micro-structure includes dry-etching a sacrificial layer provided to a silicon substrate to form structures the sacrificial layer reacting with etching gas to generate reaction products including H2O, wherein the dry-etching includes etching the sacrificial layer and removing H2O as one of the reaction products generated through the etching step of the sacrificial layer, wherein the etching and the removing of H2O are repetitively performed.