15 July 2004 Sensor for monitoring plasma parameters
Author Affiliations +
Proceedings Volume 5339, Photon Processing in Microelectronics and Photonics III; (2004) https://doi.org/10.1117/12.528991
Event: Lasers and Applications in Science and Engineering, 2004, San Jose, Ca, United States
A spectrally tunable VCSEL (vertical cavity surface-emitting laser) was used as part of sensing hardware for measurements of the radial-integrated gas temperature inside an inductively coupled plasma reactor. The data were obtained by profiling the Doppler-broadened absorption of metastable Ar atoms at 763.51 nm in argon and argon/nitrogen plasmas (3, 45, and 90% N2 in Ar) at pressure 0.5-70 Pa and inductive power of 100 and 300 W. The results were compared to rotational temperature derived from the N2 emission at the (0,0) transition of the C3Πu-B3Πg system. The differences in integrated rotational and Doppler temperatures were attributed to non-uniform spatial distributions of both temperature and thermometric species (Ar* and N2*) that varied depending on conditions. A two-dimensional, two-temperature fluid plasma simulation was employed to explain these differences. This work should facilitate further development of a miniature sensor for non-intrusive acquisition of data (temperature and densities of multiple plasma species) during micro- and nano-fabrication plasma processing, thus enabling the diagnostic-assisted continuous optimization and advanced control over the processes. Such sensors would also enable tracking the origins and pathways of damaging contaminants, thereby providing real-time feedback for adjustment of processes. Our work serves as an example of how two line-of-sight integrated temperatures derived from different thermometric species make it possible to characterize the radial non-uniformity of the plasma.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Alexander A. Bol'shakov, Alexander A. Bol'shakov, Brett A. Cruden, Brett A. Cruden, Surendra P. Sharma, Surendra P. Sharma, } "Sensor for monitoring plasma parameters", Proc. SPIE 5339, Photon Processing in Microelectronics and Photonics III, (15 July 2004); doi: 10.1117/12.528991; https://doi.org/10.1117/12.528991

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