Selective Electroless Plating of Copper on (100)-Oriented Single Crystal Silicon Surface Modified by UV-Induced Coupling of 4-Vinylpyridine with the H-Terminated Silicon

Abstract

A Sn-free electroless plating process for producing patterned and adherent copper deposits on (100)-oriented single-crystal silicon substrates is described. Pristine and resist-patterned Si(100) substrates were etched, initially, by aqueous HF to produce the hydrogen-terminated silicon surfaces (H-Si(100) surfaces). The H-Si(100) surfaces were further functionalized by the UV-induced reactive coupling of 4-vinylpyridine (4VP). The composition and topography of the modified Si(100) surfaces were characterized by X-ray photoelectron spectroscopy and atomic force microscopy, respectively. The coupled 4VP layer exhibited good stability in boiling chloroform, boiling water, sonicating dichloromethane, aqueous solution of HF and aqueous solution of KOH. Not only did the 4VP layer provide chemisorption sites for the palladium complexes without the need for prior sensitization in SnCl 2 solution during the electroless plating process but it also served as the adhesion promotion layer and diffusion barrier for the electrolessly deposited copper. The 180°-peel adhesion strength of the electroless deposited copper on the modified silicon surface was dependent on the extent of 4VP surface coverage and could reach about 4 N/cm.

Functionalization of hydrogen-terminated silicon via surface-initiated atom-transfer radical polymerization and derivatization of the polymer brushes

“…The ester-group-terminated monolayers were introduced onto the Si-H surface via a well-established technique of UV-induced coupling reaction [46,47]. The surface Si-H group is dissociated by UV to form the radical site (a dangling bond).…”

Seeded growth fabrication of Cu-on-Si electrodes for in situ ATR-SEIRAS applications

“…Unlike chemical deposition of a Cu nanofilm on Ge in which the growth of a conductive and SEIRA-active Cu nanofilm occurs by the continuous dissolution of the Ge substrate via the displacement of Ge with Cu [41], our current approach allows a Cu nanofilm on Si to be deposited via initial activation with Cu seeds followed by its further growth in a Cu chemical plating bath without continuous dissolution of Si substrate. It should be emphasized that our seeded-growth tactics is quite different from that aimed for microelectronics application in which Pd [42] or Au [43] seeds were introduced to Si wafer surfaces as the catalysts, thus preventing possible contamination in the resultant Cu nanofilm electrode by a second metal.…”

Surface-silvered polyimide films prepared by plasma-induced grafting of viologen and electroless plating

“…2(b)), after air exposure. The C 1 s core-level spectrum of the pristine PI film can be curved-fitted with five peak components, having binding energies (BE's) at 282.6 eV for the C-Si species, at 284.6 eV for the C-H and C-C species, at 285.6 eV for the C-N species, at 286.4 eV for the C-O species, and at 288.5 eV for the N (C = O) 2 species [14][15][16]. It is noted that the peak component at BE of 282.6 eV is the C-Si species introduced in the PI synthesis process.…”

“…The XPS N 1s core-level spectrum of the pristine PI film (Fig. 4(a)) shows only one peak component with the BE at about 400.5 eV, which is associated with the imide or -N(C = O) 2 species [16,21,22]. The N 1s spectrum of the PI-g-VBVN film (Fig.…”