Multifunctional Plasma Laboratory (MFPL):
Simulation and experimental activities are being undertaken for both basic and interdisciplinary research. Apart from this, both national and international collaborations are going on.
1. Development and study of a multipurpose magnetron plasma source for understanding plasma science and its application in sputtering of functional materials
A dynamic and multipurpose experimental system has been designed and developed to undertake basic and applied research on plasma sources, diagnostics, and deposition of different functional materials.
The design structure involves the generation of high-density plasmas and radicals for various applications ranging from a small (2") to a large area (8") substrate. System assembly is going on.
Funding from: SERB-DST (ongoing)
Also, looking for Industry support and funding partner for any application oriented work using this system.
2. Industry Support (Ongoing)
Development study of plasma devices for healthcare.
3. Simulation based design and under development of a capacitively coupled plasma (CCP) system for customized applications (ongoing) like PECVD
Understanding plasma source and its associated plasma behavior and plasma chemistry are the crucial factors to recognize and improve plasma processes for plasma application. For the mass scale fabrication of these materials, we require the examination of the operation/parameter space, determination of the favorable process conditions and a better understanding of the plasma.
Simulation study of a CCP system has been initiated, and the results will be used for the development of the experimental system.
Looking for Industry support for this work.
4. Simulation studies and development of an atmospheric pressure plasma (APP) JET system (ongoing)
Plasma is an ionized state of matter consisting of electrons, ions, neutrals, free radicals, and radiation, including UV light. Non-thermal atmospheric pressure plasmas (APPs) have shown the potential for numerous applications. APPs, due to their capabilities to produce highly activated species and reactive chemistries, have been studied for their use in different areas apart from surface treatment and sterilization. Considerable theoretical and experimental studies are going on to understand the mechanism of plasma generation, formation of radicals and species, and the plasma chemistry in such plasmas.
Simulation study of a CCP system has been initiated, and the results will be used for the development of the experimental system.
Also, looking forward to industrial and funding partners to take up projects and collaboration.
5. Recent development of optical diagnostic method (recently developed via a collaboration work with Nagoya University, Japan) for Ar based plasmas and industrial plasma processes
We consider corona model and local thermal equilibrium approximations of a real plasma to present measurements of electron temperature (Te) and density (ne), respectively, using optical emission spectroscopy (OES) method in dual-frequency pulsed capacitively coupled plasmas (CCPs) in a reactive mixture of Ar/O2/C4F8 at low operating pressure. The operation conditions like DC continuous and synchronized were used for the study and plasma characterization for the intended plasma application like high aspect ratio etching (HARE). We show that the present plasma conditions are dominated by a corona balance rather than the supremacy of multi-step excitation. This fact has enabled us to utilize the modified Boltzmann plot technique to evaluate Te values. In the second method, we simultaneously use the Boltzmann and Saha equations to determine the ne value using the line intensity ratio and the value of Te. Time-resolved measurements of Te and ne were performed for completeness, and the insight of the pulsed discharge is investigated. Time evolution of ne and Te using the OES method revealed a similar trend in the change of plasma parameters indicating electron impact ionization during the pulse on phase. It was seen that ne in the afterglow speedily decreased within a short time of ∼5 µs. Analysis suggests the formation of afterglow plasmas, which composed of positive and negative ions with very low electron density. Results revealed that the DC synchronized operation could be useful for the plasma application like HARE due to different plasma characteristics. It also suggests the production of ion-ion plasmas by the effective utilization of negative ions in the afterglow phase. The corona balance condition was validated in our experiments, and the results were compared with the existing literature.
This method can be useful for all laboratory and industrial plasmas operating with Ar.
6. Other diagnostic methods are being under consideration and will be developed with the support of funding projects.
Summary of my basic and interdisciplinary activities with vision and goal.
Understanding the mechanism of plasma generation in plasma sources, diagnostic development, and application of plasma sources for numerous societal applications
My collaboration activities (ongoing):
1. Collaboration with Sungkyunkwan University South Korea:
Design of plasma source, diagnostic and plasma processes for energy and electronic materials and societal applications.
Recent publication(s) via this collaboration:
3. L. Wen, B. B. Sahu, G. Y. Yeom, J. G. Han “Improved Electrical and Optical Properties of Ultra-Thin Tin Doped Indium Oxide (ITO) Thin Films by a 3-Dimensionally Confined Magnetron Sputtering Source” Sci. Advanced Mater. 13, 498 (2021). DOI: https://doi.org/10.1166/sam.2021.4020
2. L. Wen, B. B. Sahu, G. Y. Yeom and J. G. Han “Room temperature deposition of very thin and flexible crystalline ITO thin film using 3-D facing-magnetron sputtering plasma source” Vacuum, 193, 110520 (2021) (ISSN: 0042-207X). https://doi.org/10.1016/j.vacuum.2021.110520
1. N. Liu, J. Kim, J. Oh, Q. T. Nguyen, B. B. Sahu, J. G. Han and S. Kim, “Growth of multi-orientated polycrystalline MoS2 using plasma-enhanced chemical vapor deposition for efficient hydrogen evolution reactions, Nanomaterials 10, 1465 (2020) (ISSN 2079-4991). doi:10.3390/nano10081465
2. Collaboration with Nagoya University Japan:
Advanced Plasma source, probe and optical diagnostics for high aspect ratio etching for devices.
Recent publication(s) via this collaboration:
B. B. Sahu, K. Nakane, K. Ishikawa, M. Sekine, T. Tsutsumi, T. Gohira, Y. Ohya, N. Ohno and M. Hori, "Study of optical emission spectroscopy using modified Boltzmann plot in dual frequency synchronized pulsed capacitively coupled discharges with DC bias at low-pressure in Ar/O2/C4F8 plasma etching process" Phys. Chem. Chem. Phys., 2022, DOI: 10.1039/D2CP00289B, https://doi.org/10.1039/D2CP00289B
Conference papers
3. B. B. Sahu, M. Sekine, T. Tsutsumi, K. Ishikawa, H. Shogo, H. Tanaka, N. Ohno, and M. Hori, “Simple external filter and tuning for operation in dual radio frequency plasmas using compensated Langmuir probe” [ISPlasma2022/ IC-PLANTS2022 conference, hybrid Symposium, March 6-10, 2022, Nagoya University, Japan].
2. B. B. Sahu, H. Shogo, T. Tsutsumi, N. Britun, M. Sekine, K. Ishikawa, H. Tanaka, T. Gohira, Y. Ohya, N. Ohno and M. Hori, “Study of Electron Behavior using Laser Photo detachment and Dual Frequency compensated Langmuir probe in pulsed plasma etching processes” [1ST Grobal plasma forum, February 01, 2022 at Center for Low-temperature Plasma Sciences (cLPS), Hybrid conference, Nagoya University, Japan].
1. B. B. Sahu, S. Hattori, T. Tsutsumi, N. Britun, M. Sekine, K. Ishikawa, H. Tanaka, T. Gohira, Y. Ohya, N. Ohno and M. Hori, “Measurements of negative ion density and plasma parameters in Ar/O2/C4F8 etching plasmas by Langmuir probe-assisted laser photodetachment” [ISPlasma2021/ IC-PLANTS2021 conference,Virtual Symposium, March 7-11, 2021, Nagoya University, Japan].
3. Collaboration with plasma group at IITD:
Plasma Lab (Plasma Physics laboratory) at IIT Delhi is my Alma mater. The Lab is a joint activity of the Department of Energy Science and Engineering and the Physics Department with thrust on different plasma sources and plasma-based applications. Since the 1980s, the activities of the plasma lab have been expanding, and currently, there are four laboratories (including this MFPL) with various ongoing activities in different areas for societal welfare.
4. Looking for collaborating partner and industrial partner who can provide funding
Opportunity for students
Looking forward highly dedicated and hardworking students for Ph.D. work with me.
Opportunity for collaboration and consultancy with industry and funding agency
I am looking forward to industrial and funding partners to taking up projects and collaboration.
Conversation is going on with different industries to take up project with mutual interest.
Contact me at: bibhutisahu@gmail.com