Bonded films nitriding

Nitriding of steels is not in itself beneficial to bonded film performance, but Kawamura et al showed an interesting synergistic effect of soft nitriding and manganese phosphating on the wear life of a bonded molybdenum disulphide coating on an annealed steel. 

Efforts to synthesize C3N4 at high pressures have been much less extensive than those made to synthesize this material in the thin film form. A number of trials [214] indicate that it may be possible, through the use of pressure to incorporate nitrogen into sp -bonded carbon nitride. 

To obtain a metallurgical bond between two metals, the atoms of each metal must be brought sufficiently close so that their normal forces of interatomic attraction produce a bond. The surfaces of metals and alloys must not be covered with films of oxides, nitrides, or adsorbed gases. When such films are present, metal surfaces do not bond satisfactorily (see Metal surface treatments). 

There have been many other reports of single-source azido precursors, all aimed at achieving device-quality films using moderate deposition conditions. The azide precursors have the advantages of (i) having preformed Ga—N bonds and (ii) only a limited number of the undesirable Ga—C and N—C bonds which can lead to carbon incorporation into the nitride films.311 A list of azido-based precursors and deposition conditions is given in Table 14. 

In the case of H in low-temperature deposited silicon nitride films, ion beam techniques have again been used to calibrate IR absorption. The IR absorption cross sections most often quoted in the literature for Si—H and N—H bonds in plasma-deposited material are those of Lanford and Rand (1978) who used 15N nuclear reaction to calibrate their IR spectrometry. Later measurements in CVD nitride films, using similar techniques, confirmed these cross sections (Peercy et al., 1979). 

Anodic bonding can be modified to bond glass plates (i.e., Pyrex to Pyrex). To achieve this, a silicon nitride film (200 nm) was used as an adhesive layer, and the anodic bonding conditions of 1500 V, 450°C, 10 min, were used [144]. In another example, a 160- im Si3N4 film was used and the bonding conditions were 100 V, 400°C for 1 h [143],... 

When tungsten is deposited by means of CVD there is almost no adhesion to dielectric materials like silicon dioxide and silicon nitride. To overcome this problem an adhesion promoting layer prior to the tungsten deposition is deposited. Sputtered films such as TiW and TiN have received the most attention [Ellwanger et al.7, Rana et al.8] and have proven to provide adequate adhesion. With respect to this it must be emphasized that macroscopic adhesion (Scotch tape test or bond pull test) in itself is not a valid proof of adhesion. The ultimate evidence can only be obtained when... 

---