Open AccessElectroreduction of Perchlorinated Silanes for Si Electrodeposition
Author(s) -
Nathanael Downes,
Quintin Cheek,
Stephen Maldonado
Publication year - 2021
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/abda58
Subject(s) - overpotential , faraday efficiency , chemistry , chronoamperometry , electrochemistry , electrolyte , silanes , inorganic chemistry , silane , reactivity (psychology) , chemical engineering , cyclic voltammetry , electrode , organic chemistry , medicine , alternative medicine , pathology , engineering
The electrochemical reactivity and suitability of hexachlorodisilane and tetrakis(trichlorosilyl)silane as Si ec-LLS electrodeposition precursors in several electrolyte solutions have been investigated. Voltammetric data indicated that perchlorinated silanes exhibit mechanistically similar electrochemical responses as SiCl 4 , regardless of the Si–Si bond content in the precursor. The voltammetric responses were a strong function of the concentration of the precursor, indicating the participation of electrogenerated intermediates during the reduction and concomitant Si electrodeposition. Variation of the anion in the supporting electrolyte was found to be a critical factor for the thermal and chemical stability of the precursor bath. A combination of chronoamperometry and electron microscopy data were used to study the deposition efficiency specifically for hexachlorodisilane. The faradaic efficiency was low, regardless of overpotential or the composition of the electrolyte. Cumulatively, these data show that while larger chlorosilanes can be used for conventional Si electrodeposition over a wider range of conditions, their chemical instability and propensity for low faradaic efficiency limit their utility as reagents relative to SiCl 4 for Si electrodeposition by ec-LLS.