Gas Distribution Assembly for Low-Vapor-Pressure Precursor Control
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Solution Overview
Problem
Existing semiconductor manufacturing processes lack control over the flow rate of low-vapor-pressure precursors into processing chambers, leading to variations within and between processes due to uncontrolled delivery methods.
Innovation Solution
A gas distribution assembly with a flow ratio controller and mass flow meters is used to split and measure the flow of carrier gas, allowing precise control of precursor flow rates by adjusting the ratio of carrier gas portions, ensuring consistent delivery of low-vapor-pressure precursors into semiconductor processing chambers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If vapor draw or bubbling methods are used to deliver low-vapor-pressure precursors, then the precursor can be delivered into the chamber, but the flow rate becomes unmetered and uncontrolled
Solution Approach 1:
A carrier gas is introduced as an intermediary substance to transport the low-vapor-pressure precursor from the ampoule into the chamber. The carrier gas dissolves or carries the precursor through the liquid phase, enabling controlled delivery that neither pure vapor draw nor direct liquid injection can achieve alone
Solution Approach 2:
The invention replaces traditional mechanical flow control methods with gas-phase concentration detection and absorption techniques. By measuring the concentration of precursor in the gas phase and using absorption measurements, the system achieves precise flow rate control without direct mechanical metering of the liquid precursor
2Manufacturing precision
If direct liquid injection is used to meter flow rates, then precise flow control is achieved, but the method is limited to liquid precursors and requires impurity-free liquids
Solution Approach 1:
The invention changes the physical state parameter of the precursor from liquid to gas phase for measurement and control purposes. By evaporating or volatilizing the precursor and measuring its concentration in the gas phase, the system can control flow rates of precursors that would be difficult or impossible to meter directly as liquids, including those with impurities
3Measurement precision
If gas-phase concentration detection with absorption techniques is used, then flow rate measurement capability is provided, but additional measurements are required and it is not suitable for high volume manufacturing
Solution Approach 1:
The invention merges the carrier gas delivery function with the measurement function into a single integrated system. The carrier gas that transports the precursor also serves as the medium for concentration detection and absorption measurements, eliminating the need for separate measurement systems and reducing overall 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 solution enables precise control and measurement of precursor flow rates, enhancing process uniformity and repeatability by quantifying the contribution of the precursor to the total gas flow, thereby improving the consistency of semiconductor manufacturing processes.
Implementation Method 1
measuring a total gas flow after combining the first portion, the precursor gas, and the second portion
Implementation Method 2
splitting the carrier gas into a first portion and a second portion
Data Source
AI summary
Embodiments include a gas distribution assembly for a semiconductor processing chamber. In an embodiment, the gas distribution assembly comprises a flow ratio controller (FRC). In an embodiment, a first line from the FRC goes to an ampoule, and a second line from the FRC goes to a main line. In an embodiment, a third line from the ampoule goes to the main line. In an embodiment, a mass flow meter is coupled to the main line.