Raw Material Vaporizing Apparatus Concentration Control
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Solution Overview
Problem
Existing raw material vaporizing and supplying apparatuses for semiconductor manufacturing, such as those using the bubbling method, face challenges in accurately controlling and quickly responding to raw material gas concentration, leading to decreased measurement accuracy and increased manufacturing costs due to reliance on expensive equipment and complex concentration measurement methods.
Innovation Solution
A raw material vaporizing and supplying apparatus equipped with a raw material concentration detection mechanism that uses a mass flow controller, automatic pressure regulating device, and mass flow meter to compute and display the raw material gas concentration in real time, employing a constant temperature unit and arithmetic unit to stabilize internal pressure and flow rates, allowing for accurate and economical control and display of raw material gas concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a mass flow meter is used to measure mixed gas flow rate, then flow rate measurement is provided, but measurement accuracy decreases when mixed gas type or mixture ratio changes
Solution Approach 1:
The patent changes the measurement parameter from direct flow rate measurement to temperature measurement. By measuring the temperature change of the mixed gas as it passes through the heated portion of the concentration detection tube, the system achieves accurate raw material gas concentration measurement that is not affected by mixed gas type or mixture ratio variations. This parameter change resolves the contradiction by providing both high measurement precision and universal adaptability.
2Measurement precision
If expensive concentration measurement equipment is used, then measurement accuracy improves, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive concentration measurement equipment with a simple, inexpensive temperature detection system. The concentration detection tube with heated portion and temperature sensor provides accurate raw material gas concentration measurement at a fraction of the cost of conventional equipment. This substitution of cheap components for expensive ones resolves the contradiction between measurement precision and manufacturing cost.
3Ease of operation
If heating temperature is changed to regulate raw material gas flow rate, then concentration control is achieved, but response characteristics deteriorate
Solution Approach 1:
The patent replaces the thermal regulation system (heating temperature control) with a flow rate control system. By controlling the flow rate of carrier gas through the liquid raw material while maintaining constant heating temperature, the system achieves both easy concentration control and fast response characteristics. This substitution of mechanical flow control for thermal control resolves the contradiction between ease of operation and speed.
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
The apparatus achieves stable and accurate control of raw material gas concentration, enabling high-quality process treatment with reduced costs by using a simpler and less expensive system for continuous, automatic measurement and display of raw material gas concentration.
Implementation Method 1
by keeping the source tank (5) at a constant temperature by a constant temperature unit (6)
Implementation Method 2
an automatic pressure regulating device (8) is installed on a flow-out passage of the mixed gas (GS) from the source tank (5), the automatic pressure regulating device (8) is controlled so as to open and close a control valve (8a), thereby controlling an internal pressure P0 of the source tank (5) to a predetermined value
Implementation Method 3
a mass flow meter (9) is installed on a flow-out passage of the mixed gas (GS) from the source tank (5)... a flow rate QS of the mixed gas (GS) by the mass flow meter (9)
Implementation Method 4
the raw material concentration arithmetic unit (10) is used to compute a raw material flow rate Q2 based on Q2＝QS×Pm0/P0... and a raw material concentration K of the mixed gas (GS) supplied to the process chamber is computed and displayed
Implementation Method 5
supplies a carrier gas (GK) into a source tank (5) through a mass flow controller (3) to release the carrier gas (GK) from inside the source tank (5) and also supplies into a process chamber a mixed gas (GS) composed of the carrier gas (GK) and saturated steam (G) of a raw material (4)
Data Source
AI summary
An apparatus able to regulate a raw material concentration, in a mixed gas of carrier gas and raw material gas, accurately and stably to supply the mixed gas to a process chamber, with a flow rate controlled highly accurately, thereby detecting a vapor concentration of the raw material gas in the mixed gas easily and highly accurately and displaying the concentration in real time without using an expensive concentration meter, etc.