Fluid Flow Control with Burst Pressure Precharge for Stable Pulses
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Solution Overview
Problem
Existing fluid control systems for semiconductor manufacturing, such as ALD apparatus, face challenges in maintaining consistent gas flow rates due to varying pneumatic valve response times and pressure disturbances, leading to inefficiencies and waste, particularly in high-speed pulse control applications.
Innovation Solution
A fluid control apparatus with a fluid device module including a fluid resistor, pressure sensors, and a valve controlled by a feedback mechanism to achieve target burst pressure and constant flow rates, independent of valve response times, using pressure and flow rate feedback control to stabilize flow rates and eliminate waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high-speed pulse control is used to introduce required flow rates of various gases, then the film deposition precision is improved, but the temporal control accuracy deteriorates due to varying pneumatic valve response times
Solution Approach 1:
The system pre-charges gas into the volume V at a constant pressure before the pulse control period begins. This preliminary action ensures that when the pulse control starts, the gas is already ready in the volume, eliminating the need for high-speed valve response during the actual deposition process and ensuring consistent flow rates.
Solution Approach 2:
The mass flow controller performs flow rate feedback control to maintain constant gas flow into the volume V. By continuously monitoring and adjusting the flow rate, the system compensates for any variations in valve response and ensures consistent gas supply during pulse control operations.
2Speed
If pneumatic valves are used for on-off control, then the response speed is improved, but the robustness against pressure disturbances deteriorates
Solution Approach 1:
Gas is pre-charged into the volume V before the pulse control period. This preliminary charging action separates the gas supply preparation from the actual pulse control execution, allowing the system to use simple on-off valves while maintaining robustness through the decoupled preparation phase that is less sensitive to pressure disturbances.
Solution Approach 2:
The volume V acts as an intermediary between the gas supply and the deposition chamber. It buffers the gas flow, decoupling the upstream gas supply from the downstream pulse control requirements, thereby isolating the system from pressure disturbances while maintaining fast response capability.
3Adaptability or versatility
If two branch flow paths are used for pulse control, then the flow rate control capability is improved, but the device complexity increases
Solution Approach 1:
The system merges the gas charging function and the pulse control function into a single integrated flow path structure. The volume V serves both as a charging chamber and as the source for pulse control, eliminating the need for separate branch flow paths while maintaining full flow rate control capability through the mass flow controller and controlled opening/closing of the single valve.
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 solution ensures consistent burst pressure and flow rates, enhancing robustness against disturbances and simplifying the flow path configuration, while eliminating waste and improving control accuracy and efficiency in high-speed pulse control applications like ALD.
Implementation Method 1
a first pressure sensor provided on the upper stream side than the fluid resistor
Implementation Method 2
a fluid resistor provided on the upper stream side than the second valve
Implementation Method 3
the first pressure feedback controller controls the first valve so that the first pressure measured by the first pressure sensor reaches target burst pressure
Implementation Method 4
the first valve controller controls the opening degree of the first valve so that a flow rate of the gas reaching the deposition chamber becomes a constant flow rate
Data Source
AI summary
Provided is a fluid control apparatus that without enhancing temporal control performance, every time, can stabilize a fluid flow rate achieved by, for example, pulse control, and eliminate fluid wasted at the time of supplying the fluid by including one flow path. A control mechanism includes a first feedback controller adapted to control a first valve on the basis of first pressure measured by a first pressure sensor. In addition, when a second valve is closed, the first pressure feedback controller controls the first valve so that the first pressure measured by the first pressure sensor reaches target burst pressure, and when and after the first pressure reaches the target burst pressure and the second valve is opened, the control mechanism is configured to control the first valve so that the flow rate of the fluid flowing through the flow path reaches a target constant flow rate.