Abstract
Electroless plating of nickel (or copper) was carried out on glass (or silicon) substrates that were previously surface modified by using plasma-polymerization and grafting processes, and then activated by immersion in a simple acidic PdCl2 solution. Three pretreatments based on the deposition of plasma-polymerized thin films (PACVD process) on O2 plasma-cleaned substrates were investigated. They include film deposition of (1) amorphous hydrogenated carbon (a-C:H) grown from CH4, whose surface is subsequently plasma-functionalized in NH3 or N2; (2) amorphous hydrogenated carbon nitride (a-CNx:H) grown from CH4/NH3 or CH4/N2 mixtures; and (3) amorphous hydrogenated carbon nitride grown from volatile organic precursors (allylamine, acetonitrile).
In the three cases, X-ray photoelectron spectroscopy (XPS) results show that chemisorption of the catalyst occurs on the nitrogen-containing functionalities created by plasma polymerization and grafting and thus that the electroless deposition is possible. Differences were observed depending on the nature and thickness of the plasma-polymerized thin films, as well as on the nature and concentration of the nitrogen-containing functionalities present or grafted at the surface. Practical adhesion of Ni films was investigated using a Scotch® tape test. Ni films up to 3 or 4 μm in thickness were shown to pass this test successfully, i.e., without causing any metal detachment.
Notes
Presented in part at the 26th Annual Meeting of The Adhesion Society, Inc., Myrtle Beach, South Carolina, USA, 23–26 February 2003.
The adhesion data are relative to the Ni film maximum thickness, which is obtained without any metal squares removed (cross-hatched tape test: Test Value (TV) = 5). Routes (a), (b), and (c) are relative to schemes given in .
The adhesion data are relative to the Ni film maximum thickness, which is obtained without any metal squares removed (cross-hatched tape test: Test Value (TV) = 5).