Precursor Vessel Headspace Shaping for Uniform Gas Saturation
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Solution Overview
Problem
Existing precursor delivery systems for semiconductor processing face challenges in efficiently providing precursor vapors, especially for precursors with low volatility, which can lead to decomposition when maintained at high temperatures for extended periods.
Innovation Solution
A vessel design with a unique shape that varies the vertical distance between the precursor surface and the upper interior surface, creating a non-cylindrical headspace, ensures uniform precursor gas saturation across different gas flow paths, thereby enhancing the efficiency of precursor delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the precursor is heated to increase vapor pressure for low volatility substances, then the vapor pressure increases, but the precursor decomposes when maintained at high temperatures for long periods
Solution Approach 1:
The vessel is pre-heated to a temperature sufficient to generate adequate vapor pressure before the precursor is introduced. This preliminary heating action ensures that when the precursor enters the vessel, the vaporization process begins immediately without requiring extended exposure to high temperatures, thereby preventing decomposition while achieving the necessary vapor pressure for low volatility precursors
Solution Approach 2:
The system dynamically adjusts the heating temperature based on the specific precursor being used. The vessel can be heated to different temperatures optimized for each precursor's volatility characteristics, allowing sufficient vapor pressure generation while minimizing thermal exposure time and preventing decomposition through temperature optimization
2Quantity of substance
If a large quantity of precursor is provided in the vessel for bubbler method, then the carrier gas becomes saturated with precursor vapor, but the unstable precursor decomposes
Solution Approach 1:
The system changes the temperature parameter to optimize the balance between vapor saturation and precursor stability. By controlling the vessel temperature at an optimal level, sufficient precursor vapor is generated to saturate the carrier gas while maintaining the temperature below the decomposition threshold, eliminating the need to use excessive precursor quantities
3Device complexity
If the vessel has uniform height for gas flow paths, then the structure is simple, but the precursor gas saturation is non-uniform across different gas flow paths
Solution Approach 1:
The vessel employs an asymmetric height configuration where different regions of the vessel have different heights. This asymmetric design creates varied gas flow path lengths that compensate for positional differences, ensuring that gas molecules regardless of their entry point experience similar effective path lengths and achieve uniform precursor gas saturation across all flow paths
Solution Approach 2:
Different regions of the vessel are designed with locally optimized heights tailored to their specific positions. Regions closer to the inlet have different heights compared to regions farther away, with each local region's height optimized to achieve uniform gas saturation throughout the vessel, ensuring consistent precursor delivery across all output locations
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 vessel design achieves substantially full saturation of the carrier gas with precursor gas, improving the efficiency and reliability of precursor delivery systems, reducing precursor decomposition, and enhancing the effectiveness of semiconductor processing.
Implementation Method 1
The precursor vapor diffuses into the inert gas and is carried along with the carrier gas out of the vessel and to the reactor chamber
Implementation Method 2
The heating means heats up the vessel to increase the vapor pressure of precursor gas in the vessel
Implementation Method 3
The heating means heats up the vessel to increase the vapor pressure of precursor gas in the vessel
Implementation Method 4
As the bubbles rise, precursor evaporates from the surface of the bubbles towards the center of the bubbles
Data Source
AI summary
A vessel for containing a precursor in liquid or solid form is disclosed. The vessel comprises an inlet port for supplying a gas to the interior of the vessel and an outlet port for removing a gas from the interior of the vessel, the inlet port and the outlet port being spaced apart in a first direction, the vessel comprising an upper interior surface and a bottom, opposite interior surface, the upper surface being arranged to face the precursor contained in the vessel in use. The vessel is shaped such that a vertical distance between a top surface of the precursor and the upper interior surface of the vessel varies between the inlet and the outlet, having a minimum value at a point located between the inlet and the outlet in the first direction.