In semiconductor manufacturer and IC package, electroless deposition (ELD) of nickel/phosphorous (Ni/P) film is a special promising skill [1]. In general, the core of ELD is a catalytic reaction that needs a trace amount of noble metal such as palladium as the activator to lower the activation energy of metal formation [2]. Because the adhesion of ELD Ni/P film relates to the interfacial characteristic of catalyst and silicon surface. In order to enhance the bridging between the silicon substrate and palladium (Pd) catalyst, modifying silicon surface with organo-silane compound such as 3-[2-(2-aminoethylamino)ethylamino] propyl-trimethoxysilane (ETAS) is commonly used. The ETAS treatment then forms a self-assembled monolayer (SAM) which is capable to interact with polymer-capped Pd catalyst and thereby promotes the adsorption of ELD Ni/P film [3]. However, it is known that the SAM formation is very sensitive to process condition such as soaking time and solvent agents.

In this study, various ETAS modification on silicon wafer are investigated. In particular, the ETAS-modified film was done by a wet-soaking method in which  the influence of soaking time and solvent agents onto silicon surface were discussed. As shown in Fig 1, the AFM images with various solvent agents of ETAS-modified surface showed significant difference which indicates that the solvent agents does influence SAM formation. The correlation on the solvent effect and the adhesion of ELD Ni/P on ETAS-modified silicon surface are discussed.

REFERENCES

[1] A. Brenner, G.E. Riddell, J. Res. Nat'l Bur. Std. 37 (1946) 31.

[2] L. Li, B. Liu, Mater. Chem. Phys. 128 (2011) 303.

[3] T. C. Wei, T. P. Pan, C. M. Chen, K. C. Lai, C. H. Wu, Electrochem. Commun. 54 (2015) 6