A simple, direct route to preparation of surface immobilized hydrogel films is described. Specifically, low pressure RF pulsed plasma polymerization of 1-amino-2-propanol and 2-(ethylamino)ethanol monomers produced thin hydrogel films deposited on substrates located in the plasma reactor. The successful syntheses were carried out under plasma conditions which not only yield the hydrogel but are also sufficiently energetic to produce films strongly grafted to the substrates. The polymer films obtained exhibit the thermoresponsive property of hydrogels, as shown by film color change with temperature. Additional evidence for the phase transition properties of these films was obtained using water contact angle and capillary rise measurements. The plasma polymerization approach provides an unusually simple route to synthesis of hydrogels in which the films are pin-hole free and are of easily controlled thickness. An important added advantage, particularly for applications involving biomaterials, is the conformal property of the plasma generated polymer films. The results obtained suggest that this approach should be applicable to a variety of other monomers and, based on differences observed with the present two monomers, suggest synthesis of films which exhibit a range of phase transition temperatures.

On-chip microscopic corrosion, originating from contact of dissimilar metals, can cause serious reliability issues for integrated circuits and microelectromechanical devices. A new micropattern corrosion screening method combined with Tafel plots were employed to study Cu bimetallic corrosion in acid and base solutions relevant to the chemical-mechanical planarization process. The results demonstrated that Cu corrosion on Ru is much more severe compared to Cu corrosion on Ta substrates. Tafel plots confirm the nobility trend of Ru [ Cu [ Ta. The micropattern corrosion study shows the Cu bimetallic corrosion depends on specific chemicals and bimetallic contacts. Strong complexing ligands like NH 3 combined with energetically favorable Cu/Ru bimetallic contact promote faster Cu corrosion under alkaline conditions (9 B pH B 11.4). Micropattern corrosion screening was shown to be useful in identifying the metastable surface layer during Cu corrosion and determining the optimal benzotriazole concentration for Cu corrosion inhibition.

On-chip corrosion within Cu interconnect microstructures can result in increased defectivity that causes serious reliability issues and decreases production yield. This active bimetallic corrosion is especially of concern when Cu/barrier contacts are directly exposed to corrosive chemicals during CMP and post CMP clean processes. In this paper, a new, rapid, corrosion screening metrology was developed using both micropattern corrosion testing and high resolution 3-D optical profilometry. Micropattern screening revealed that gallic acid, often perceived as anti-oxidant, is actually rather corrosive to Cu at pH ≥ 9. Increased Cu corrosion rates were found in oxygen rich ambients and with direct contact to nobler barriers like Ru. Efficient micropattern screening also enabled the discovery of new Cu corrosion inhibitors. The initial inhibition activation on the Cu surface was studied by 3-D optical profilometry.

Plasma etching and ashing processes on intricate porous low-k dielectrics are known to introduce high levels of defects that may cause serious reliability issues. Post etch cleans to remove polymer residues could also further damage the porous low-k dielectrics. Compounding the difficulty of handling weak porous ULK materials, a lack of sensitive metrology to evaluate such damage is a serious hindrance to systematic development of plasma etching, restoration and cleaning processes. In this paper, a new metrology tool using Multiple Internal Reflection Infrared Spectroscopy (MIR-IR) was developed and tested using silicon wafer based IR waveguides. Our data demonstrates the capability of MIR-IR spectroscopy to monitor removal of thin polymeric post-plasma etch residues from porous low-k dielectrics and characterize plasma-induced dielectric damage.

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