Characterization of bubbler performance for low-volatility liquid precursor delivery

Area of Science:

• Materials Science
• Chemical Engineering
• Semiconductor Manufacturing

Background:

• Low-volatility liquid precursors are essential for advanced deposition techniques.
• Accurate delivery of these precursors is critical for process control and film quality.
• Cobalt precursors like CCTBA are used in specialized semiconductor applications.

Purpose of the Study:

• To characterize the performance of a bubbler system for delivering cobalt precursor (CCTBA).
• To investigate the influence of process parameters (carrier gas flow rate, system pressure, bubbler temperature) on precursor delivery.
• To develop and validate a model for predicting precursor flow rates.

Main Methods:

• Experimental characterization of bubbler performance across a wide process window.
• Measurement of CCTBA partial pressure using a custom non-dispersive infrared gas analyzer.
• Development of a predictive model incorporating headspace partial pressure and pressure drop.

Main Results:

• CCTBA flow rates were accurately measured and modeled under various conditions.
• A model assuming constant partial pressure and including pressure drop showed good agreement with experimental data.
• The temperature dependence of CCTBA partial pressure was successfully parameterized using the August equation.

Conclusions:

• The bubbler system demonstrates reliable performance for delivering CCTBA.
• The developed model provides a deeper understanding of factors influencing bubbler performance.
• The findings are applicable to other low-volatility liquid precursors in vapor deposition processes.