Comparative investigations of structure and properties of BCN coatings deposited by thermal and plasma-enhanced CVD

Abstract

Hard BCN films were deposited by chemical vapour deposition (CVD) on Si(100) substrates. TCVD (thermal activated) and PECVD (GD or RF microwave plasma-activated, respectively) were used. The films were analysed with respect to chemical state, composition, morphology and microstructure, oxidation behaviour and hardness. Wavelength dispersive X-ray spectroscopy (EPMA), infrared spectroscopy (IR), transmission electron microscopy (TEM), differential thermal analysis (DTA) and hardness evaluation were employed for film characterization. A correlation between deposition parameters and film composition, structure and hardness could be proved in every CVD process. Parallels between TCVD and PECVD films emerged in the case of chemical composition and the correlation between carbon content and hardness values. Considerable differences exist with regard to the microstructure, especially the texture of the films. Moreover in TCVD films the carbon is preferentially incorporated between the BN basal planes, whereas in PECVD films it is incorporated preferentially in as well as between the BN basal planes.

Plasma CVD of B–C–N thin films using triethylboron in argon–nitrogen plasma

“…, C and N content of the deposited films, from ERDA measurements, in this work (red filled circles) compared to previously reported atomic content of plasma CVD B-C-N films deposited below 500 1C, using TBBD (open circles),5 PB (plus signs),5 N-TEBA (filled squares),10,11 N-TMBA (stars),6,35 TMAB (open triangles),13 B 2 H 6 -CH 4 -N 2 mixtures (open squares)…”

“…The stoichiometries of deposited films are summarized in the ternary diagram in Fig. 2 (red filled circles) and with the compositions compared to selected studies using TBBD (open circles), 5 PB (plus signs), 5 N-TEBA (filled squares), 10,11 N-TMBA (stars), 6,35 TMAB (open triangles), 13 36 and BCl 3 -CH 4 -N 2 mixtures (crosses). 37 From XPS spectra in Fig.…”

“…13,14 The incorporation of nitrogen in the films has been found to be important to increase the bandgap in B-C-N materials, making them more insulating. 15 The highest nitrogen content achieved without additional nitrogen source in the plasma CVD process are 28 at% using N-TMBA, 6 43 at% using N-TEBA, 10 38 at% using TDMAB, 12 20 at% using triethylamineboron 7 and, 12 at% using trimethylamineboron. 13 Studies on the deposition chemistry suggest that the B-N bonds in the precursor molecules are not the major source of nitrogen in the film, 13,14 and ammonia (NH 3 ) or dinitrogen (N 2 ) are typically added to the plasma to increase the N content in the films.…”

Plasma CVD of B-C-N Thin Films Using Triethylboron in Argon-Nitrogen Plasma

“…The interaction between total flow and N/Ar ratio is ascribed to a higher dissociation of N2 at higher total flows, given the higher number of collisions with a higher number of molecules. Please do not adjust margins Please do not adjust margins (filled squares) 10,11 , N-TMBA (stars) 6,33 , TMAB (open triangles) 13 , B2H6-CH4-N2 mixtures (open squares) 34 and BCl3-CH4-N2 mixtures (crosses) 35 .…”

“…No correlation between the deposition parameters and the atomic composition of the films could be made. The stoichiometries of deposited films are summarized in the ternary diagram in Fig 2 (red filled circles) and with the compositions compared to selected studies using TBBD (open circles) 5 , PB (plus signs) 5 , N-TEBA (filled squares) 10,11 , N-TMBA (stars) 6,33 , TMAB (open triangles) 13 , B2H6-CH4-N2 mixtures (open squares) 34 and BCl3-CH4-N2 mixtures (crosses) 35 .…”