HMNEX: "SMI Localizes Key Next-Generation Semiconductor Component, 'Optical Temperature Sensor'"

HMNEX announced on January 8 that its subsidiary SMI has successfully localized the Optical Temperature Sensor-a key component in next-generation semiconductor processes-for the first time in Korea, and has passed the final Qualification Test at Micron’s Singapore plant.

Since August 2025, SMI has been conducting tests at Micron’s Singapore plant by installing optical temperature sensors to verify wafer yield and process stability. It was confirmed that final approval was granted this month. With this approval, SMI has secured a foundation to supply domestically produced optical temperature sensors in earnest to global semiconductor mass production lines.

The monthly usage of optical temperature sensors at Micron’s Singapore plant is estimated to be about 1,200 units. The company plans to supply more than 10% of this monthly usage in 2026. After 2027, it expects to expand orders to 50-60%. Actual order intake is expected to begin in the first quarter of this year.

The optical temperature sensor is a precision sensor that measures temperature by detecting changes in the properties of light, rather than electrical signals, inside a semiconductor plasma etching process chamber. It uses optical fiber as a medium and is also known as a “fiber optic temperature sensor.” The sensor tip is coated with a special chemical compound, and after irradiation with light, the fluorescence is filtered and the decay time of the fluorescent material is analyzed to measure the temperature. Unlike traditional thermocouples or RTDs, which are difficult to use in environments with strong electromagnetic interference, high voltage, or explosion risk, this sensor operates reliably even under such conditions. Its non-contact method makes it advantageous for high-temperature, high-voltage, rotating, and vacuum environments.

The core competitiveness of the optical temperature sensor lies in its precision and lifespan, which are determined by the composition and ratio of the chemicals used. SMI explained that it has secured proprietary chemical formulation technology through extensive research and development, enabling the production of customized sensors tailored to customer requirements.

Whereas conventional optical sensors typically have a service life of 1 to 1.5 months, SMI’s product is evaluated to last up to six months, providing advantages in terms of reduced maintenance costs and enhanced process stability.

Starting with Micron Singapore, SMI plans to expand the application of its optical temperature sensors to global semiconductor companies. Major potential customers include SK hynix, Samsung Electronics, Micron (Japan, USA, Taiwan), TSMC, and China’s CXMT. Currently, Micron Japan and China’s CXMT are reportedly conducting qualification tests.

An SMI representative stated, “Passing Micron Singapore’s qualification test is significant as it demonstrates that our domestically produced optical temperature sensor meets the stringent standards of global semiconductor companies. We plan to expand the development of customized optical sensor systems to a variety of industries that require high-temperature and high-risk environments, beyond the semiconductor sector.”