Precursor Source Vessel Surface Sensing for Stable Vapor Pressure
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Solution Overview
Problem
Conventional temperature sensors in semiconductor processing systems fail to accurately measure the surface temperature of liquid precursors, leading to inconsistent vapor pressure control, especially in larger vessels, which affects semiconductor processing due to condensation and vapor pressure fluctuations.
Innovation Solution
A source vessel design with a floating temperature sensor, infrared temperature sensor, or vertically distributed thermocouples, combined with a liquid-level sensing system, to accurately measure and control the surface temperature of liquid precursors, maintaining a desired vapor pressure through a controlled temperature gradient.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional thermocouple is positioned near the bottom of the vessel to measure temperature, then the temperature sensor is simple and easy to install, but the temperature reading does not accurately represent the surface temperature of the liquid precursor
Solution Approach 1:
The patent employs a floating temperature sensor that dynamically adjusts its position to remain at the liquid surface level. The sensor is coupled to a float mechanism that rises and falls with the liquid level, ensuring continuous accurate measurement of surface temperature regardless of liquid volume changes in the vessel.
Solution Approach 2:
The patent introduces a float mechanism as an intermediary between the temperature sensor and the liquid surface. The float serves as a mediator that transfers the liquid level information to the sensor position, allowing the sensor to indirectly track the surface temperature through its coupling with the float's vertical movement.
2Productivity
If the source vessel size is increased to store more liquid precursor, then the productivity is improved by reducing recharge frequency, but the temperature reading accuracy deteriorates because the thermocouple cannot accurately represent the surface temperature
Solution Approach 1:
The floating temperature sensor dynamically adapts to the liquid level in the enlarged vessel, maintaining accurate surface temperature measurement regardless of the increased vessel size or liquid volume. This dynamic positioning allows accurate measurement in larger vessels where fixed thermocouples fail.
3Object-affected harmful factors
If an overall heat control methodology is used to create a temperature gradient from top to bottom to prevent condensation, then condensation is prevented, but the liquid surface temperature becomes inconsistent due to changing liquid levels
Solution Approach 1:
The patent implements a feedback control system that continuously monitors the liquid surface temperature via the floating sensor and adjusts the heating power accordingly. The controller receives temperature data from the sensor and modulates the heater to maintain a consistent surface temperature, compensating for temperature gradient effects and liquid level changes.
Solution Approach 2:
The floating temperature sensor dynamically tracks the liquid surface temperature as levels change, providing real-time feedback that allows the control system to adapt heating power to maintain consistent surface temperature despite variations in liquid level and temperature gradient conditions.
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
Ensures consistent vapor pressure control by accurately measuring and maintaining surface temperatures, preventing condensation and ensuring precise semiconductor processing.
Implementation Method 1
a temperature sensor configured to detect a temperature of a surface of the liquid-state precursor
Implementation Method 2
a heating system configured to heat the liquid-state precursor in the chamber
Implementation Method 3
the source vessel can be operated so as to cause the vapor pressure to remain constant
Implementation Method 4
creating and maintaining a temperature gradient in the liquid precursor in the source vessel to ensure there are higher temperatures at the top versus the bottom
Data Source
AI summary
A source vessel for use in a semiconductor processing system to supply precursor materials by providing enhanced control over vapor pressures. The source vessel includes a housing or vessel defining a chamber for holding a volume of precursor in a liquid state. The source vessel further includes a temperature sensor configured to detect a temperature of a surface of the liquid-state precursor that is presently contained within the chamber of the housing. The temperature sensor may take the form of a temperature measurement device such as a thermocouple on a float or a non-contact temperature measurement device such as an infrared (IR) temperature sensor with a line-of-sight to the liquid's surface.