Near coalescent submicron polycrystalline diamond films deposited on silicon: Hydrogen bonding and thermal enhanced carbide formation

作者：Stacey A; Michaelson Sh; Orwa J; Rubanov S; Prawer S; Cowie B C C; Hoffman A^*

来源：Journal of Applied Physics, 2009, 106(10): 103503.

DOI：10.1063/1.3257255

The influence of high temperature annealing up to 1200 degrees C in vacuum on similar to 100 nm nearly continuous thick diamond films consisting of 30-50 nm crystallites, deposited onto silicon substrates is reported. The hydrogen bonding and phase composition of the films were studied with Raman spectroscopy, while the surface microstructure and composition were studied with high resolution scanning electron microscopy (SEM), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS), respectively. Annealing to 800-900 degrees C of similar to 100 nm thick films results in a decrease in the intensities of the peaks associated with hydrogen bonding (Raman), as well as changes to the morphological microstructure at the film surface. Heating the films to 1000 degrees C resulted in the complete disappearance of the Raman peaks associated with hydrogen bonding at grain boundaries, and an increase in the relative intensity of the diamond peak relative to the graphite-related D and G Raman peaks, concomitant with changes to the microstructure (SEM and TEM). Ex situ XP analysis of the films annealed to 800 and 1000 degrees C provides clear evidence for the formation of SiC on the films surface and near surface region. However a sharp SiC Raman peak at 796 cm(-1) appears only after annealing to 1200 degrees C and it is concomitant with a decrease in the Raman peaks associated with sp(2) bonded carbon. Our results suggest that formation of SiC phase preferentially consumes sp(2)/sp hybridized carbon matrix, produced by thermal desorption of hydrogen atoms at diamond grain boundary and at the diamond film-silicon substrate interface.

• 出版日期2009-11-15