Creating More Sustainable Chemical Vapor Deposition Methods

Benefits of sustainable CVD methods are clear: less waste, less energy, higher-quality products

Published: Thursday, March 31, 2022 - 11:03

As more people become environmentally conscious, manufacturers need to keep ahead of growing concerns about carbon emissions and potentially harmful waste products. Thin-film deposition plays a critical role in many sustainable technologies, including solar power and energy storage.

Unfortunately, many current thin-film deposition processes are unsustainable. Some are time- and energy-consuming, while others are highly hazardous and produce harmful byproducts.

Fortunately, many researchers are looking into methods to reduce the environmental impact of many deposition processes and produce sustainable solutions that are appealing to manufacturers and regulators alike.

What is chemical-vapor deposition?

Chemical vapor deposition (CVD) is a thin-film deposition process that uses chemical reactions between gaseous reagents to coat the surface of a heated substrate. The process offers many benefits not provided by physical vapor deposition (PVD), mainly since the reactive materials are gaseous.

This means that the process doesn’t need a line of sight between the target material and substrate, and it’s possible to coat multiple parts in one reaction.

Typical applications of CVD include:
• Cutting tools coated with damage-resistant ceramics
• Medical equipment coated with titanium nitride
• Microelectronic components
• Data storage
• Solar products

Is CVD green?

Unfortunately, current CVD practices are not green. Many are energy intensive, and more advanced processes use more energy than established, mature techniques. For example, the energy consumption and greenhouse gas emissions for new 2 nm node CMOS wafers are double that of existing 28 nm node processes. Because almost all electronic devices need a CMOS chip, this new process will have a devastating effect on the environment.

Other environmental challenges facing current CVD practices include:
• The use of greenhouse gases in the process
• Low precursor utilization
• Reliance on high temperatures translates into increased energy cost
• Synthetic precursors that have an environmental footprint

Combating these challenges requires considerable effort from entire industries and regulators, given that changes may affect productivity and profitability.

Current research on sustainable CVD methods

Current research into sustainable CVD processes needs to focus on three key aspects:
• Reducing total energy consumption
• Increasing efficiency and utilization rate
• Reducing the use and formation of hazardous molecules

These changes must affect every aspect of the production chain, from synthesizing the precursor molecule to waste gas abatement.

Green chemistry is a growing research field that aims to streamline current chemical synthesis pathways. The main principles of green chemistry align clearly with sustainable CVD methods because the principles seek to use the lowest possible temperature and fewest possible steps to produce the highest number of atoms from the starting material.

CVD is an inherently energy intensive process that requires elevated temperatures. However, there are still ways to reduce temperatures, such as using a time-resolved precursor supply combined with plasma discharge to reduce substrate temperatures significantly.

Final thoughts

While current chemical vapor deposition methods aren’t sustainable, manufacturers have plenty of opportunities and options to change their practices. The benefits of sustainable CVD methods are clear: They would produce less waste, use less energy, and produce higher-quality products. As research continues, the uptake of these greener processes should also increase to the benefit of all involved.

About The Author

Jessica Hilton

Jessica Hilton, Ph.D., is the product manager at Korvus Technology Ltd. and a physicist trained in experimental condensed matter physics. She completed a Ph.D. in May 2019 working on the synthesis, structural, and physical characterization of functional materials. Hilton also blogs at korvustech.com and loves to write about science and innovation on the web.