Chaudhary, Deepika and Sharma, Mansi and Sudhakar, S. and Kumar, Sushil (2016) Investigation of powder dynamics in silane-argon discharge using impedance analyser. Physics of Plasmas, 23 (12). ISSN 1070-664X

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We report the growth of powder formation in Argon (Ar) diluted Silane (SiH4) plasma using 27.12 MHz assisted Plasma Enhanced Chemical Vapor Deposition process with the approach of plasma diagnosis. The appearance of powder during processing contaminates the process chamber which further can alter the film properties; hence plasma diagnosis was vital towards detecting this variation. This work presents for the first time a diagnosis of powder in the plasma using Impedance Analyser (V/I probe) at various concentrations of Argon dilution (10%-90%), chamber pressure (0.3 Torr-0.6 Torr), and applied power (4 W-20 W). Efforts were made to understand the different phases of powder formation (i.e., chain and accumulation process, coalescence phase and alpha -> gamma' transition (powder zone)) by monitoring and evaluating the plasma characteristics such as discharge voltage and current (V-rms and Irms), Impedance (Z), phase angle (phi), electron density (n(e)), bulk field (E-b), and sheath width (d(s)). From the results of plasma characterization, the coalescence phase can be well diagnosed by the low amplitude of I-rms, phi, n(e), and d(s) in combination with a high amplitude of V-rms and E-b whereas alpha -> gamma' transition regime diagnose by a lower value of V-rms, Z, phi, E-b, and d(s) with a higher value of I-rms and n(e) which signifies the presence of powder in the plasma. It was also observed that with the increase of applied power, the coalescence phase gets shifted towards the lower Ar dilution percentage. Conversely, the phase transition region from amorphous (a-Si:H) to microcrystalline (mu c-Si:H) thin film will observe at the onset of powder formation thus on account of plasma results, deposition of silicon thin films was carried out, and the film properties are in good agreement with plasma characteristics.

Item Type: Article
Additional Information: Copyright for this article belongs to M/s AIP Publishing.
Subjects: Physics > Physics of Fluids and Plasmas
Depositing User: Dr. Rajpal Walke
Date Deposited: 30 Jan 2018 08:28
Last Modified: 30 Jan 2018 08:28

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