Pressure-Based Precursor Level Sensing Under Carrier Gas Conditions
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Solution Overview
Problem
Current methods for monitoring the amount of solid precursors in semiconductor manufacturing processes are inaccurate and challenging due to high temperature conditions and the use of carrier gases, making it difficult to reliably measure the remaining precursor material in precursor vessels.
Innovation Solution
A pressure-based sensor system comprising two fluidly connected chambers with a known volume and a pressure sensor that measures pressures using a probing gas to determine the amount of solid precursor, allowing for accurate and consistent measurements without tool downtime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If carrier gas is used to transport solid precursor from precursor vessel to reactor chamber, then precursor can be delivered to workpiece, but measurement of remaining precursor becomes inaccurate and challenging
Solution Approach 1:
A probing gas is introduced as an intermediary substance to interact with the solid precursor in the precursor vessel. The probing gas allows indirect measurement of precursor amount through pressure changes, avoiding direct contact between measurement devices and the precursor material, thus enabling accurate measurement despite the presence of carrier gas and high temperature conditions
Solution Approach 2:
The patent replaces traditional mechanical level sensing systems with a pressure-based measurement system. Instead of using mechanical sensors that would be affected by high temperature and carrier gas, the system uses pressure measurements of probing gas to infer precursor levels, substituting a mechanical approach with a thermodynamic approach that is more reliable under process conditions
2Measurement precision
If existing level sensing systems are used under high temperature and carrier gas conditions, then precursor monitoring is attempted, but measurement accuracy and resolution deteriorate
Solution Approach 1:
The probing gas serves as a mediator that can withstand high temperature conditions and carrier gas environment while allowing pressure-based measurement. This intermediary approach enables precise measurement without exposing sensitive measurement components to harsh thermal and chemical conditions that would degrade traditional sensors
Solution Approach 2:
The system measures pressure changes of the probing gas as an indirect parameter to determine precursor levels, rather than directly measuring physical dimensions or properties that would be affected by temperature. This parameter transformation allows accurate measurement under high temperature conditions by monitoring a parameter (pressure) that remains stable and measurable
3Productivity
If precursor vessel changes are scheduled without accurate monitoring, then operational simplicity is maintained, but process quality and chemistry utilization efficiency decrease
Solution Approach 1:
The pressure-based measurement system provides continuous feedback on the amount of precursor remaining in the vessel. This information feeds back to the control system, enabling optimized scheduling of precursor vessel changes based on actual precursor levels rather than fixed schedules, thus maximizing chemistry utilization and preventing premature or delayed vessel changes
Solution Approach 2:
The measurement system enables the precursor delivery system to self-monitor and self-regulate its operation. By providing real-time information on precursor levels, the system allows automated decision-making regarding when to change vessels, improving productivity and reducing manual intervention while maintaining optimal chemistry utilization
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 improves the accuracy and consistency of precursor measurements, enabling near real-time monitoring and quality control, preventing the use of low-quality chemical films by detecting precursor exhaustion and impurities.
Implementation Method 1
a pressure sensor configured to measure a plurality of pressures in said chambers when a probing gas is supplied thereto
Data Source
AI summary
A pressure-based sensor system is described by which the amount of solid precursor in a precursor vessel for a semiconductor manufacturing process can be determined. The system comprises at least two fluidly connected chambers having a known volume, and a pressure sensor configured to measure a plurality of pressures in said chambers.