Plasma Diagnostics III

Real-time and accurate diagnosis of electron density is essential in current and next-generation semiconductors and display plasma processes to enhance wafer processing outcomes and increase production yield. Microwave plasma diagnostic methods, such as the flat cutoff sensor, have been explored; however, most existing sensors require maintaining a coaxial structure up to the sensing point or have a thickness of several millimeters. To overcome these limitations, we developed a Patch-Type Cutoff Sensor, which enables microwave transmission and plasma diagnosis without needing a continuous coaxial structure. The sensor structure was optimized through electromagnetic wave simulations, which also confirmed the measurement accuracy under varying plasma conditions. Its capability to detect bulk plasma characteristics was experimentally demonstrated. Additionally, the sensor's potential for predicting wafer processing results was confirmed by comparing sensor diagnostics with actual process outcomes, highlighting its value as a diagnostic tool in semiconductors and display manufacturing processes.

Funding acknowledgement

This research was supported by the Technology Innovation Program, funded by the Ministry of Trade, Industry & Energy(MOTIE, Korea) (grant nos. RS-2024-00507767,00508070, 2410000200, 2410000258, 2410003567); Ministry of Science and ICT and the R&D Convergence Program of the National Research Foundation (NRF) of Korea (grant no. CRC20015-000) ; Korea Semiconductor Research Consortium (KSRC) (grant nos. 00235950, 00237058); Korea Research Institute of Standards and Science (grant no. KRISS GP2025-0013-02); 2023 Korea Aerospace University Faculty Research (grant no. 202300250001)