It has been suggested that CF series gases used in semiconductor etching may face usage restrictions due to their high global warming potential, and that preparations for supply restrictions are necessary.

Korea SEMI held 'SMC Korea 2022' online from the 18th to the 31st.

At this event, Samsung Electronics Master Yoonjung Cho presented on the topic of ‘Challenges and Opportunities of Next-Generation Semiconductor Materials.’

Master Cho Yoon-jung stated that while an increase in the use of CF-series special gases is inevitable, they have high global warming indices, so their use may be discontinued at some point in the future, and so preparations for this are necessary.

Master Cho Yoon-jung stated that in the case of special gases in the CF series, since they must be used to control the aspect ratio during the HARC process in 3D NAND 3D stacks, there is currently no substitute and their usage will continue to increase in the future.

hyeonThe five special gases with high global warming potential (GWP) used in the re-etching process are CF4, CHF3, C4F6, C4F8, and SF6. CF4 has a CWP of 6,500, CHF3 has a GWP of 11,700, C4F6 has a GWP of 9,200, C4F8 has a GWP of 8,700, and SF6 has a GWP of 23,900, so they all have high GWPs.

Accordingly, the industry is developing gases that can replace these special gases, but this will likely take considerable time as it will be difficult to convert the semiconductor process.

In particular, the method currently being studied is to maintain the amount of use of these gases while minimizing emissions through treatment facilities. In this case, if the amount of use or production is restricted in Europe and other countries due to global political reasons due to the recent spread of international ESG, there is a very high possibility that supply problems will arise.

According to Master Cho Yoon-jung, there are currently alternative materials that have been developed and are in the process of being developed, but a complete replacement is not possible at this time, and it will take a considerable amount of time to find a replacement.

In addition, it is expected that as low-temperature processes spread in the future, cryogenic etching gases will be widely used, and even if cryogenic etching gases are used, it will be difficult to completely replace CF series gases and the amount used will not decrease.

Accordingly, collaboration with materials and equipment companies on the development of alternative gases is essential, and solving material issues will become a key issue in future semiconductor processes, he said.

Meanwhile, e4ds, our magazine, will hold the ' 2022 e4ds Semiconductor Trend DAY' event at COEX Room 327 on June 10. This seminar will present the latest trends in semiconductors, precursors, special gases, and next-generation memory semiconductors.