AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Generation of Controlled Fluxes of Nanoparticles to a Substrate by Pulsed Radio-Frequency Hydrogen-Silane Dusty Plasmas
PARTH SHAH, Carlos Larriba-Andaluz, Steven Girshick, University of Minnesota
Abstract Number: 660 Working Group: Nanoparticles and Materials Synthesis
Abstract Silicon nanoparticle deposition onto a substrate can be a means to epitaxial film growth at low temperature. It is hypothesized that this can be achieved if the nanoparticles’ impact energy and size can be controlled by pulsing the plasma and by applying a positive DC bias to the substrate during the afterglow phase of each pulse in order to accelerate and collect the negatively charged nanoparticles. In recent work (1) this concept was explored using a 1D numerical model of an argon-silane plasma. However hydrogen-silane plasmas are more widely used for deposition of silicon thin films, because hydrogen promotes film crystallization. Hydrogen and argon differ in important respects that affect this process, including both clustering chemistry and particle charging. Compared to argon, hydrogen tends to suppress nucleation. Also, because of the lighter mass of H ions compared to Ar, nanoparticles are less negatively charged in the hydrogen case. Here we use a similar model as in Ref. 1, but with more detailed hydrogen plasma chemistry, to conduct numerical simulations for the hydrogen-silane case. Conditions include 13.56-MHz frequency, total pressure of 2 Torr, and a 2-cm electrode gap. Simulations were conducted for a range of pulse parameters, including pulse frequency and duty cycle, and DC bias voltage during the afterglow phase of each pulse.
This work was partially supported by the National Science Foundation (CHE-124752), Dept. of Energy Office of Fusion Energy Science (DE-SC0001939), and the Minnesota Supercomputing Institute.
(1) C. Larriba-Andaluz and S. L. Girshick, AAAR 2015, abstract.