The Korea Institute of Materials Science (KIMS, President Choi Cheol-jin) has developed the world's first transparent, plasma-resistant high-entropy ceramic, raising expectations that it will solve the problems of corrosion and contamination caused by plasma during semiconductor etching processes.

The Korea Materials Research Institute announced on the 15th that the research team led by Dr. Ma Ho-jin of the Nanomaterials Research Center, in collaboration with the research team led by Professor Lee Jeong-woo of Pusan National University, succeeded in developing a new composition and process technology for transparent, plasma-resistant, high-entropy ceramics that extend the lifespan of internal components of etching equipment during the semiconductor manufacturing process and reduce contaminant particles for the first time in the world.

Ceramics account for over 90% of the materials used in semiconductor etching equipment. One reason for this is their higher plasma resistance (ability to withstand plasma) than other materials. Just as a ship rusts when exposed to seawater, the plasma used in the etching process continuously reacts with internal equipment components, causing corrosion and contamination. Therefore, ceramics are used as a material to reduce such problems.

On the other hand, as the etching process is performed in increasingly harsh environments due to the high integration of semiconductors, the frequency of replacement of commonly used ceramic components is increasing, hindering semiconductor productivity.

The research team designed a new high-entropy ceramic composition that overcomes the limitations of the existing ceramic materials mainly used, such as yttria (Y2O3), alumina (Al2O3), and YAG, and developed a transparent ceramic with a density of 99.9% through a sintering process technology for a dense solid material with no porosity.

Such dense bodies are used in etching process equipment that requires plasma resistance.

Additionally, the research team confirmed the change in the crystal structure of the elements that make up the high-entropy ceramic and developed a transparent ceramic that can transmit visible light and infrared rays using a technology that controls pores.

High-entropy ceramics, unlike general materials, are ceramics that form a single phase (uniform structure) by mixing five or more elements without forming impurities. High-entropy ceramics are known to exhibit new properties, such as high heat resistance, excellent wear resistance, and low thermal conductivity, unlike existing materials, and are attracting attention as heat shielding materials, catalysts, and energy storage materials.

On the other hand, research on plasma resistance had not been conducted until now, so our research team focused on this and conducted research, successfully conducting research and development for the first time in the world.

In semiconductor processes, materials with low etch rates mean fewer contaminants and greater durability.

The high-entropy transparent ceramic developed by the research team showed a low etching rate of 1.13% compared to sapphire.

In addition, compared to yttria (Y2O3), which is known to have excellent plasma resistance, the etching rate was only 8.25%, demonstrating excellent durability.

Ma Ho-jin, a senior researcher at the Korea Materials Research Institute, said, “In the plasma etching process of the semiconductor process, materials, parts, and equipment from the United States and Japan account for more than 90%, so the domestic industry is severely dependent on foreign countries.” He added, “This research result is a representative example of developing a high-entropy ceramic that has never been studied before, and developing a world-class plasma-resistant material with domestic technology. At the same time, we expect it to become the cornerstone for achieving local production of parts through material independence.”

This research was conducted with support from the Korea Institute of Materials Science (KIM). The results were published online on January 13th in the Journal of Advanced Ceramics (IF: 18.6), a globally influential academic journal in the field of ceramic materials.