Electroless Metallization of Silicon Using Metal Nanoparticles as Catalysts and Binding-Points

Abstract

Gold nanoparticles on silicon work not only as catalysts to initiateautocatalytic electroless metal deposition but also as bindingpointsbetween the deposited metal film and the silicon surface.Conventional catalysts of autocatalytic electroless metal deposition,such as palladium and silver, require heat treatments or anchorformation to obtain practical adhesion of deposited metal films onsilicon. Gold nanoparticles can directly produce adhesive metalfilms on flat silicon surfaces without any treatments. Crosssectionaltransmission electron microscopic observation revealsthat gold nanoparticles form an alloy with silicon at the roomtemperature. This alloy is expected to improve the adhesion ofmetal film on silicon.

Adhesion and Interfacial Structure of Metal Film Electrolessly Deposited on Si Using Au Nanoparticles as Catalysts

“…Single crystalline p-type silicon (100) wafers were used as substrates. Pretreatments of the silicon substrates, displacement deposition of the gold nanoparticles, and autocatalytic electroless deposition of the nickel-phosphorus alloy films were carried out in the same way as done in the previous study (4). Gold, silver, and palladium were compared for their capabilities as the catalyst for the autocatalytic electroless deposition of adhesive metal films on silicon substrates.…”

Contact Resistance Measurements for Electrodes on Silicon Prepared by Autocatalytic Electroless Metallization Using Metal Nanoparticles

“…Rt is expressed as follows: Rt = 2Rm + 2Rc + Rs. [1] where Rm is the sheet resistance of the metal, Rc the contact resistance between the electrode and silicon, and Rs the sheet resistance of the silicon substrate. When Rm is much lower than Rc, the latter is approximated as one half of the y-intercept (2R) of the line extrapolated from measurements of Rt as a function of the length of contact spacing ( ), while the transfer length (Lt), and sheet resistance of the substrate (Rs) are respectively determined from the x-intercept ( 2Lt), and slope (Rs/Z) of the line.…”

“…Recently, we reported on the autocatalytic electroless metallization of silicon using gold nanoparticles (1). This technique is expected to replace sputtering of back metals for power devices and screen printing of thick-film electrodes for solar cells.…”

Modification of Silicon Surface with Silver, Gold and Palladium Nanostructures via Galvanic Substitution in DMSO and DMF Solutions

“…Galvanic substitution is one of the promising methods of the silicon surface modification with metallic nanoparticles and nanofilms [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Silver [1][2][3][4], gold [4][5][6][7][8][9][10], platinum [11][12][13], and platinum metals [14][15][16] are widely used for this purpose. Copper [17,18] is used seldom.…”

“…Nanoparticles of noble metals in the M/Si surface system are effective for "metal" etching of silicon in HF based solutions to obtain a homogeneous porous layer or nanowires [11-13, 15, 16]. This method is the basis for the formation of antireflective semiconductor surface to produce effective solar cells; the metallization of the silicon surface with gold is widely used to apply the electrical contacts on them [6][7][8][9][10]. In the M/Si surface system the silicon substrate causes the formation of electron-deficient nanoparticles of metal that increases catalytic activity, as shown, for example, for palladium [14] and silver [3].…”