Ampoule Auto-Refill Control for Stable Precursor Liquid Levels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor manufacturing, the refilling process of ampoules used in deposition processes leads to variations in pressure and temperature, causing process drift and increased complexity and costs due to the need for heating elements and precise gas flow control.
Innovation Solution
An auto-refill system with liquid level sensors positioned along the ampoule's height, which activate and deactivate a bulk valve to control the refilling process, ensuring consistent liquid levels and minimizing temperature fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If heating elements are added to the ampoule to control temperature during refilling, then temperature stability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The system uses self-regulating thermal expansion mechanisms where the liquid precursor naturally expands when heated by the carrier gas flow, eliminating the need for external heating elements. The ampoule design allows passive temperature control through the inherent physical properties of the liquid precursor and gas flow dynamics.
Solution Approach 2:
The invention removes heating elements from the ampoule structure, extracting the temperature control function from active components and replacing it with passive thermal management through optimized gas flow and ampoule geometry.
2Measurement precision
If multiple liquid level sensors are used to precisely control refilling, then liquid level precision is improved, but device complexity increases
Solution Approach 1:
The ampoule is divided into multiple zones with different liquid level sensors positioned at specific heights, allowing segmented monitoring of liquid levels. This enables precise control by detecting levels at critical thresholds without requiring a single complex continuous measurement system.
Solution Approach 2:
The system uses gas flow as an intermediary to transfer information about liquid levels to external sensors, allowing non-contact detection and simplified sensor integration that reduces overall system complexity while maintaining precision.
3Productivity
If manual refilling procedures are used, then system simplicity is maintained, but productivity and throughput decrease
Solution Approach 1:
The refilling system is designed to operate autonomously using self-regulating mechanisms where liquid levels automatically trigger refilling operations through buoyant float actuators. The system monitors and controls its own refilling needs without external intervention, enabling continuous operation and improved productivity.
Solution Approach 2:
The system performs preliminary refilling actions automatically when liquid levels reach predetermined thresholds, ensuring that ampoules are replenished before depletion occurs. This proactive approach maintains continuous production flow without manual intervention or system downtime.
4Reliability
If precise gas flow control is implemented during refilling, then process stability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The system incorporates feedback loops where liquid level sensors continuously monitor precursor levels and automatically adjust gas flow rates to maintain optimal refilling conditions. This closed-loop control ensures process stability while using simple, readily available components rather than complex control systems.
Solution Approach 2:
The invention controls refilling by changing gas flow parameters (rate, temperature, pressure) in response to liquid level conditions, using physical parameter adjustments rather than complex mechanical or electronic control mechanisms to maintain process stability.
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 auto-refill system maintains consistent liquid levels and reduces temperature variations, enhancing process stability and reducing system complexity and costs by automating the refilling process.
Implementation Method 1
Each of the liquid level sensors is positioned at a known location vertically along a height of an inner surface of the ampoule. Each of the liquid level sensors is configured to send a signal to a sensor controller for detecting a liquid level in the ampoule.
Implementation Method 2
The gas delivery controller is prompted to activate the bulk valve when the liquid level is at the low liquid level L, and the gas delivery controller is prompted to deactivate the bulk valve when the liquid level is at the fill liquid level state.
Implementation Method 3
A carrier gas flows through a gas delivery system to a processing chamber. The gas delivery system delivers a liquid precursor from a reservoir, through a bulk valve, through a gas conduit to the processing chamber.
Implementation Method 4
Precursor vapor is usually generated thermally inside a closed container or ampoule. Molecules of the precursor are then delivered to a substrate surface inside the processing chamber through a gas delivery gas conduit.
Implementation Method 5
Precursor vapor (e.g., metal-organic precursor vapor) is commonly used for film deposition processes including the thermal deposition of one or more precursor vapors in a processing chamber.
Implementation Method 6
Due to lower temperature of fresh liquid, temperature of the liquid in the ampoule drops and causes process drift, which is conventionally controlled by pre-heating the precursor or including heating elements within the closed container or ampoule
Data Source
AI summary
An system, method and software for controlling processes of an auto-refill system of an ampoule including one or more sensors configured to determine one or more liquid level heights within the ampoule. The auto-refill system having a state machine configured to control the auto-refill system, the state machine having one or more states for refilling the ampoule.