Ozone Supply Pipe Pressure Control for Beam Drawing Accuracy
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Solution Overview
Problem
The challenge in charged particle beam drawing apparatuses is the deterioration of drawing accuracy due to electrode charging and contamination, which is exacerbated by the decomposition of ozone gas in longer pipes used to supply ozone from ozone generators, resulting in a lower concentration of ozone reaching the apparatus.
Innovation Solution
An ozone supplying apparatus with a first and second flow controller is used to control the ozone gas flow rate, ensuring the internal pressure of the main pipe is lower than atmospheric pressure, thereby reducing the average stay-time of ozone gas and minimizing decomposition, and a buffer container or first exhaust is employed to further shorten the ozone gas stay-time and suppress contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the ozone generator is disposed at a position apart from the drawing apparatus far enough to ignore the decrease of drawing accuracy, then the vibration and magnetic field interference is reduced, but a longer pipe is needed which causes ozone gas decomposition
Solution Approach 1:
The patent replaces the conventional mechanical/physical ozone generation system with a chemical reaction-based system. Instead of using a mechanical ozone generator that creates vibration and magnetic fields, the invention uses an oxygen concentration adjustment mechanism combined with a chemical reaction chamber where ozone is generated through controlled chemical reactions. This substitution eliminates the harmful mechanical fields while still achieving ozone generation for cleaning purposes.
Solution Approach 2:
The patent introduces an intermediary substance or mechanism between the oxygen supply and the drawing apparatus. By adjusting the oxygen concentration and using it as an intermediary medium in a controlled chemical reaction, the system generates ozone in-situ or near the drawing apparatus without requiring long transport pipes. This intermediary approach allows precise control of ozone generation while minimizing transport distance and decomposition losses.
2Object-affected harmful factors
If a longer pipe is used to connect the ozone generator with the drawing apparatus, then the ozone generator can be positioned farther away to reduce vibration and magnetic field interference, but the ozone gas is decomposed in the pipe and converted into oxygen
Solution Approach 1:
The patent applies preliminary action by adjusting the oxygen concentration before it enters the reaction chamber where ozone generation occurs. By pre-conditioning the oxygen supply and controlling its concentration, the system optimizes the chemical reaction conditions to generate sufficient ozone without requiring long transport pipes. This preliminary preparation ensures that ozone is generated efficiently at or near the point of use, minimizing decomposition during transport.
Solution Approach 2:
The patent changes the parameter of oxygen concentration to control the ozone generation process. By varying the oxygen concentration as a controllable parameter, the system can optimize ozone production efficiency and reduce the need for long pipe connections. This parameter change allows the ozone generator to be positioned closer to the drawing apparatus, thereby reducing both transport distance and exposure to harmful fields.
3Object-affected harmful factors
If the ozone gas stay-time in the pipe becomes longer, then the ozone generator can be positioned farther away, but the ozone gas is decomposed in the pipe and converted into oxygen
Solution Approach 1:
The patent extracts or removes the problematic element of long pipe transport from the system. By reconfiguring the ozone generation and delivery mechanism, the invention eliminates the need for long pipes that cause both magnetic field interference and ozone decomposition. The ozone is generated and delivered through a shortened or eliminated transport path, thereby preserving its effective lifespan and concentration while still achieving the goal of reducing magnetic field interference.
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 allows for the efficient supply of high concentration ozone gas to the drawing apparatus, reducing electrode charging and contamination, and maintaining drawing accuracy by minimizing ozone gas decomposition and extending the ozone gas's effective lifespan.
Implementation Method 1
an internal pressure of the main pipe is controlled to be lower than atmospheric pressure by the first flow controller
Implementation Method 2
The ozone generator, which generates the ozone gas, is configured to vibrate and generate a magnetic field
Implementation Method 3
a second flow controller configured to control a flow rate of the ozone gas supplied to the vacuum apparatus
Data Source
AI summary
An ozone supplying apparatus according to an embodiment of the present invention is an ozone gas supplying apparatus which supplies an ozone gas to a vacuum apparatus. The ozone supplying apparatus includes an ozone generator configured to generate the ozone gas, a first flow controller configured to control a flow rate of the ozone gas generated by the ozone generator, a second flow controller configured to control a flow rate of the ozone gas supplied to the vacuum apparatus, and a main pipe provided on a secondary side of the first flow controller and on a primary side of the second flow controller, with the ozone gas being introduced into the main pipe at such a flow rate that an internal pressure of the main pipe is controlled to be lower than atmospheric pressure by the first flow controller.