Structure Of Boron Nitride Films Research Articles

Erratum to: The influences of filament temperature on the structure of boron nitride films and its tribological characterization for microforming die application

Boron nitride film was deposited on 〈1 0 0〉-oriented silicon substrate by hot filament assisted chemical vapor deposition. The B[N(CH 3 ) 2 ] 3 (Tris(dimetylamino)borane, TDMAB) was used as the single source precursor both for boron and nitride, and ammonia gas was used as the extra source to increase the N concentration in the films. Elemental composition of the films deposited under different filament temperatures were measured by energy dispersive X-ray (EDX) analysis, and the structure of the films were measured by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The boron nitride films deposited under lower filament temperature was amorphous, while BN films contain hexagonal structure were deposited at higher filament temperature. To verify whether the films can be applied to the microforming die, a ball on disk test was carried out using pure titanium ball as the counterpart to investigate the interfacial behavior between the films and pure titanium. The results show that the reaction between the films and pure titanium was low as there was no titanium adhesion on the wear track when the film was remained.

The influences of filament temperature on the structure of boron nitride films and its tribological characterization for microforming die application

Boron nitride film was deposited on 〈1 0 0〉-oriented silicon substrate by hot filament assisted chemical vapor deposition. The B[N(CH3)2]3 (Tris(dimetylamino)borane, TDMAB) was used as the single source precursor both for boron and nitride, and ammonia gas was used as the extra source to increase the N concentration in the films. Elemental composition of the films deposited under different filament temperatures were measured by energy dispersive X-ray (EDX) analysis, and the structure of the films were measured by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The boron nitride films deposited under lower filament temperature was amorphous, while BN films contain hexagonal structure were deposited at higher filament temperature. To verify whether the films can be applied to the microforming die, a ball on disk test was carried out using pure titanium ball as the counterpart to investigate the interfacial behavior between the films and pure titanium. The results show that the reaction between the films and pure titanium was low as there was no titanium adhesion on the wear track when the film was remained.

Research on the piezoelectric response of cubic and hexagonal boron nitride films

Boron nitride (BN) films for high-frequency surface acoustic wave (SAW) devices are deposited on Ti/Al/Si(111) wafers by radio frequency (RF) magnetron sputtering. The structure of BN films is investigated by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) spectra, and the surface morphology and piezoelectric properties of BN films are characterized by atomic force microscopy (AFM). The results show that when the flow ratio of nitrogen and argon is 2:18, the cubic BN (c-BN) film is deposited with high purity and c-axis orientation, and when the flow ratio of nitrogen and argon is 4:20, the hexagonal BN (h-BN) film is deposited with high c-axis orientation. Both particles are uniform and compact, and the roughnesses are 1.5 nm and 2.29 nm, respectively. The h-BN films have better piezoelectric response and distribution than the c-BN films.

Synthesis and characterization of BN thin films prepared by plasma MOCVD with organoboron precursors

Boron nitride (BN) films have contributed to improvement of tribological parts. For this study, we prepared films using plasma MOCVD with an organoborate precursor and investigated the mechanical properties and structure of BN films. The BN films were formed on specimens of silicon wafers and tungsten carbide (WC) substrates at low temperatures of less than 500 °C. Hardness tests were carried out to evaluate mechanical properties of BN films. The structure of BN films was investigated using XRD, Raman, and FT-IR spectra.

Stress measurement and stress relaxation during magnetron sputter deposition of cubic boron nitride thin films

Dynamic in situ analysis of stress and film thickness provide fast and more physical information on growth and stress evolution in cBN layers than integrating (ex situ) methods. Especially, features of the layered structure of boron nitride films, like the evolution of instantaneous stress and growth rates during deposition can be resolved by in situ methods. This work is concerned with dynamic in-situ stress measurement by means of cantilever bending during magnetron sputter deposition of cBN thin films. Laser deflection in combination with in situ ellipsometry is used to determine the instantaneous stress of the films. The results show in agreement with results that were obtained previously from ion beam assisted deposition (IBAD), that the hBN and cBN layers exhibit different levels of stress under constant deposition conditions. The stress increases from less than −4 GPa to very high values (−10 GPa) after the coalescence of the cBN nuclei. Therefore, it is possible to establish the point of cBN nucleation instantly. A simultaneous medium energy ion bombardment is used for stress relaxation during film deposition. A modified substrate bias voltage, combining negative high and low voltage pulses, is used to enable an ion bombardment of the growing film with energies up to 8 keV. In this way, cBN films with a stress as low as −1.7 GPa could be produced without destroying the sp 3-bonds significantly.

Near-edge X-ray absorption fine structure spectroscopy of arcjet-deposited cubic boron nitride

Abstract Near-edge X-ray absorption fine structure (NEXAFS) spectroscopy was employed to help determine the structure of boron nitride films grown by bias-enhanced chemical vapor deposition in a low-density supersonic arcjet flow. BN films containing 0.90% cubic boron nitride were analyzed by NEXAFS and compared with c-BN and h-BN reference spectra. The mainly cubic films have been shown previously to be nanocrystalline, which leads to the inability to obtain structural information from Raman scattering spectra. However, with NEXAFS, the nanocrystalline nature of the films does not strongly affect the structural interpretation. It is shown that films deposited with a bias of −75 V are primarily sp 3 bonded. This high sp 3 bonding character agrees with previous measrements based on infraredtransmission and reflectance spectroscopy, as well as X-ray photoelectron spectroscopy.

Investigations on the structure of boron nitride films

Boron nitride films fabricated by ion beam assisted deposition (IBAD) have been analyzed using polarized infrared reflection spectroscopy (PIRR), generalized variable angle of incidence spectroscopic ellipsometry (gVASE), elastic recoil detection analysis (ERDA), and in situ ellipsometry during plasma etching. Hexagonal boron nitride (h-BN) films, with properties very similar to the interface material on top of which cubic boron nitride (c-BN) nucleates, have been prepared. PIRR and gVASE results show that these films are biaxially anisotropic. The h-BN basal planes are aligned to the surface normal and exhibit a preferential alignment parallel to the direction of the boron vapor stream. This behavior is unrelated to the substrate crystal orientation. The observed preferential alignment of the h-BN basal planes cannot be explained by compressive stress or ion beam induced processes. The biaxially anisotropic optical properties of these h-BN films can be employed to fabricate special optical thin film devices but require the application of generalized ellipsometry also for in situ measurements.

Evidence for Layered Structure of Boron Nitride Films Detected by Rutherford Backscattering

Evidence for Layered Structure of Boron Nitride Films Detected by Rutherford Backscattering

Room temperature synthesis of cubic boron nitride films by pulse high energy density plasma

Cubic boron nitride films have been prepared on the Si(100) oriented substrate at room temperature by a pulse high energy density plasma (PHEDP). The pulse plasma is generated in a coaxial plasma gun. The working gas was a mixture of 50%B 2H 6 + 50%N 2. The structure of boron nitride films strongly depends on the voltages between inner and outer electrodes. The boron nitride films were characterized by scanning electron microscopy, electron diffraction and infrared absorption spectroscopy.

Composition and structure of boron nitride films deposited by chemical vapor deposition from borazine

The composition and structure of boron nitride films prepared by thermal and plasma enhanced chemical vapor deposition (CVD) using borazine as a precursor have been studied. Thermal CVD at temperatures between 475 and 550 °C using either a hot-wall or cold-wall reactor results in amorphous boron-rich films of approximate composition BN0.67. Plasma enhanced CVD consistently gives films of 1:1 boron to nitrogen stoichiometry, but the hydrogen content of films deposited below 300 °C is so high that the films react with atmospheric moisture. Optimum conditions for the growth of stoichiometric BN with relatively low hydrogen content were found to be low plasma power, hydrogen–borazine gas mixtures, and a substrate temperature of 550 °C. Films deposited under these conditions are mixtures of poorly crystalline hexagonal and cubic boron nitride.