Plasma-deposited nitride

Titanium alloys may be very abrasive to forging dies. Die lives are improved with surface treatments such as welding (MIG, TIG, etc.), gas and ion nitriding, carbon nitriding, plasma deposition, and surface alloying. 

Plasma-deposited siUcon nitride contains large amounts of hydrogen, typically in the range of 20—25 atomic % H, and has polymer-like properties. The electrical resistivity of the film depends on the deposition temperature, the film stoichiometry, and the amounts of hydrogen and oxygen in the film. 

Ming, Y. and Kramer, D. J., Properties of Carbon Nitride Films Deposited With and Without Electron Resonance Plasma Assistance, Thin Solid Films, Vol. 382, 2001, pp. 4-12. 

Popov, C., Zambov, L. M., Plass, M. R, and Kulisch, W., Optical, Electrical and Mechanical Properties of Nitrogen-rich Carbon Nitride Films Deposited by Inductively Coupled Plasma Chemical Vapor Deposition," Thin Solid Films, Vol. 377-378,2000, pp. 156-162. 

Research on plasma-deposited a-C(N) H films has been frequently included in the general discussion of carbon nitride solids [2, 3]. However, the presence of hydrogen in its composition, and the complexity of the deposition process, which introduces the nitrogen species in the already intricate hydrocarbon plasma-deposition mechanism, make a-C(N) H films deserve special consideration. This is the aim of the present work to review and to discuss the main results on the growth, structure, and properties of plasma-deposited a-C(N) H films. As this subject is closely related to a-C H films, a summary of the main aspects relative to the plasma deposition of a-C H films, their structure, and the relationship between the main process parameters governing film structure and properties is presented... 

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). 

Experiments like those described above have been performed to evaluate sodium ion barrier properties of Hitachi PIQ and DuPont PI 2540 polyimide films. Also included in the comparison were silicon nitride coatings plasma deposited in both tensile and compressive stress modes. The structure of the samples is illustrated in Figure 9. N-type, (111) oriented silicon substrates were cleaned and oxidized in dry oxygen ambient at 1100°C to form a 1060 A Si02 film. Wafers intended for polyimide characterization were coated with an organic silane film (gamma glycidal amino propyl trimethoxysilane) to promote adhesion of the polyimide to the oxide surface. The polyimide resins were spun onto the wafers at speeds to produce final... 

Osenbach, J. W. Sodium diffusion in plasma-deposited amorphous oxygen-doped silicon-nitride (alpha-SiON H) films. Journal of Apphed Physics 63, 4494—4500 (1988). 

Although CVD and plasma deposited films offer excellent properties as a passivation layer, the inability to reproduce chemical and physical properties has been a problem. Depending on gas flow rates and deposition conditions, free Si, H, C and 0 may be Incorporated into the films. Characterization of these films has been restricted almost exclusively to surface analytical techniques and ellipsometry. AES and XPS have been used to determine the C, N, 0, and Si content of CVD silicon nitride. 

Silicon nitride films deposited in para 11 el-pi ate, plasma-enhanced CVD reactors will be discussed in greater detail in a later chapter. However, they typically have a refractive index on the order of 2.0, partly because of hydrogen incorporated into the layer, and the ECR films appear similar. Also, as... 

Silicon nitride is deposited by PECVD using typically SiH4/NHj mixtures [238]. As with any PECVD process, the film composition and properties are a strong function of the feedstock gas composition and the plasma parameters (pressure, gas flow. 

Amorphous silicon nitride films, which are resistant to water vapor, salts, and other chemicals and, therefore, are applied as a final encapsulating layer for ICs, are effectively produced using PECVD. A typical feed-gas mixture for PECVD is SiH4-NH3. The process is performed in plasma at pressures of 0.25-3 Torr conventional substrate temperatures are in the range 250-500°C. Deposition rates of silicon nitride films under such conditions are about 20-50 nm/min. The plasma deposited silicon nitride film can usually be characterized... 

Chromium nitride layers (fabricated by, e.g. cathodic arc plasma deposition) are interesting because of their corrosion properties as well as because of their excellent adhesion properties and fine-grained structure. They are applied for die-casting moulds where excellent edge properties are necessary [115,116] some of these layer can have a multiphase character composed of Cr(N), Cr2N, and CrNi t [117]. Sputter deposited ternary chromium nitrides such as Cr fMe (N with Me = Ti, Nb, Mo, and W additions and with grain sizes of up to 25 nm have been found [118] to show either a hardness minimum (Me = Mo, Ti) or a maximum of up to 27GPa (Me-W, Nb). 

Laser-assisted CVD of BN can originate from a gaseous reactant [58], or the plasma can be formed by irradiating a target consisting mainly of BN [59 to 63, 139]. The cluster distribution of boron nitride in a laser plasma and the structure of the BN phases in the case of laser-induced plasma deposition have been studied [64]. It is also reported that a combination of an electron cyclotron plasma with laser irradiation produces a coating which consists of p-BN and y-BN [65]. 

CVD processes are well suited for the deposition of refractory coatings such as titanium carbides or nitrides, as well as for the fabrication of amorphous or microcrystalline carbon coatings. Conventional CVD processes normally require high temperatures, which limits the number of substrates that can be treated. To circumvent this problem a number of processes have been developed that use a plasma to enhance the reaction rate (plasma enhanced CVD). These processes combine chemical reactions typical for CVD with plasma deposition typical for PVD and therefore the two types of processes increasingly overlap. 

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