Full text loading...
Raman spectra of SiC films deposited at various growth temperatures. The left vertical dotted line corresponds to the standard TO phonon at . The right vertical dashed line corresponds to the longitudinal optical phonon at . A representative XRD spectrum of the porous films grown at with flow rate ratio of 100 is shown in the inset.
SEM images of porous film deposited at (a) 875 and (b) at with flow rate ratio of 100. The circle highlights a pinhole while the square shows a pit. Scale bar: . Cross sectional SEM images of porous film deposited at and . The images clearly show the presence of (c) pinhole and (d) pit (the dotted line identifies original Si substrate surface). Scale bar: 500 nm.
The evolution of pore size and pore areal density of SiC films with deposition temperatures, , and growth time of 30 min.
Proposed formation mechanism for SiC porous film. (a) Flow of hydrogen gas in the reactor during the heating up stage and formation of etch pits due to etching. (b) Formation of SiC nuclei and a large amount of HCl byproduct gas upon MTS introduction to the reactor. (c) HCl gas further etches away Si substrate (the dotted line identifies original Si substrate surface) and makes the SiC nuclei grow along the voids to form pinholes and pits.
Article metrics loading...