First Domestic Production of 6-Inch Lithium Tantalate, a Key Material for Wireless Communication

Securing Single Crystal Technology for SAW Filters
Korea Photonics Technology Institute Succeeds in Large-Diameter Growth
Localization of Key Materials Previously Dependent on Imports

The Korea Photonics Technology Institute has achieved South Korea's first successful growth of a 6-inch lithium tantalate (LiTaO₃) single crystal ingot for high-frequency filters used in wireless mobile communications.

The Image Information Research Division of the institute announced on April 30 that it had succeeded in growing a 6-inch diameter LiTaO₃ single crystal using the Czochralski method, which involves single crystal growth technology in a high-temperature environment exceeding 1,600 degrees Celsius.

From the left, Seonhoon Kim, Director of Korea Photonics Technology Institute, Wonbae Son, Senior Researcher, Junhyuk Kang, Researcher, Sujong Jeon, Researcher, and Junghwan In, Center Director.

LiTaO₃ is a single crystal material with excellent acoustic, optical, and piezoelectric properties, and serves as a key material for wireless communication filters. SAW filters selectively filter specific frequencies, and approximately 30 or more are used in a single smartphone. As mobile communication technology advances, the demand for filters is also increasing.

Currently, South Korea relies entirely on imports for LiTaO₃ substrates, which are the core material for SAW filters, with major suppliers including Japan, Germany, and China. In particular, Japanese companies are promoting a transition from 4-inch to 6-inch substrates to improve productivity and profitability.

The institute was designated as a National Core Technology Research Group by the Ministry of Science and ICT in 2022, and has been conducting research to localize single crystal materials for high-frequency filters. After succeeding in growing 4-inch single crystals last year, the research group has now expanded its technological scope to 6-inch large-diameter single crystals.

Kim Seonhoon, Director of the Image Information Research Division, stated, "Even major overseas companies are still in the early stages of commercializing 6-inch diameter single crystals. Based on this achievement, we expect not only to achieve self-sufficiency in domestic communication materials, but also to expand applications into various fields such as quantum technology."