Figure 3.
a) SEM images of VGs on ZrO2/Si substrates. The VGs were grown at a condition having 8 sccm CH4, 50 sccm H2, and 50 sccm Ar for 6 h. Reproduced with permission.27 Copyright 2017, Elsevier Ltd. Optical microscopy image of ≈750 nm HfO2 nanoparticle film grown on SiO2/Si substrate b) before and d) after CVD in CH4/H2 at 950 °C. HRTEM images of the HfO2 nanoparticles scratched from the film c) before and e–g) after CVD. Insets in (b) and (d) show the FFT analysis of the respective HfO2 nanoparticles. h) Raman spectra for the HfO2 nanoparticles before and after CVD with CH4 and H2 at 950 °C. Reproduced with permission.32 Copyright 2011, Wiley‐VCH.