Sputtering boron nitrides

Within an N/B ratio of 1 to 0.3 (at%) the N 1s and B Is peaks consisted of at least two well distinguishable branches. This splitting has been attributed to isolated structures occurring in deposits formed either by a neutral process without ion enhancement or in radiofrequency-sputtered boron nitride. Intensity changes after ion milling are probably due to the abundance of hydrogen in the films [15]. 

The effects of substrate temperature (Ts b) on cubic boron nitride (c-BN) films synthesized using magnetron sputtering were studied. Fourier transform infrared (FTIR) spectroscopy. X-ray photoelectron spectroscopy (XPS) were employed to characterize the structure and composition of the films. It is found that Ts , plays a crucial role on the formation of cubic phase, and an appropriate T, , can lead to a high content. A tentative explanation on the mechanism of such Ts b effects is reported with the most details. 

Simultaneous ion-enhanced deposition leads to a more homogeneous coating. Such processes are described in a number of articles and patents [88 to 100]. While ions are accelerated to energies of 120 keV, a modification of such methods involves the use of low-energy nitrogen ion beams (from 200 to 5000 eV) [101 to 106]. The dependence of the formation of p-BN on the bias voltage has been studied in the reactive diode sputtering of boron nitride [107]. Sputter-deposition of BN layers is also mentioned in patents [89 to 110]. 

Cubic boron nitride films have also been prepared by activated reactive evaporation of boric acid in an NH3 plasma formed between a hot filament and an anode [119 to 121]. Other reports on ionized deposition of BN layers [122,123] and on p-BN deposited by sputtering in an NH3 or N2/Ar atmosphere [124, 125] show that the formation of the different BN phases in the resultant coatings depends critically on the conditions of the process. About the effects of the total gas pressure and the type of sputtering gas on the stresses of thin p-BN films, see [138]. 

By cosputtering Cr and BN by magnetron radiofrequency sputtering, amorphous Cr/BN films are obtained which have superconducting transition temperatures up to 1.14 K and an orbital contribution (i.e., (dHc2 /dT)jc) as large as 49 kOe/K. In order to be amorphous, the boron nitride content in the film must be >15%. The same behavior is observed with Mo/BN films [53]. 

Ceramic materials such as Si3N4 [50] or TiN [51] can be coated with p-BN by plasma-enhanced or sputter chemical vapor deposition (CVD), or diamond coatings (by excited CVD) can be doped with boron upon admixture of B2H6 to the CH4/H2 plasma [52]. See Section 4.1.1.2.3, p. 13, for hard boron nitride coatings. 

Polytetrafluoroethylene coatings deposited together with boron nitride by radiofrequency sputtering are applied to molded rubber parts in order to reduce their dynamic friction [27] the same holds true for perfluoropolyether compositions [28]. 

As a boron nitride film, a B-C-N passivation film can also be deposited by plasma-enhanced CVD in semiconductor devices [9], and hydrogenated boron nitride carbide films are applied for X-ray mask membranes. The radiofrequency (13.56 MHz) plasma-enhanced CVD process uses B2H6, CH4, and Ng or NH3 as source gases, or in a sputtering process with a boron target, CH4, N2, and Ar are used [10 to 18]. A B-C-N mixed phase can also be prepared by N" ion implantation into B4C at 100 keV [19]. 

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