CVD seeding


The quality of thin diamond films grown by Chemical Vapor Deposition (CVD) depends on the uniformity, density, particle size distribution and disaggregation level of nanodiamonds used for initial nucleation.
RayND - nanodiamonds produced by RAY technology of Light Hydro-Dynamic Pulse (LHDP) are of high purity and homogeneity. Nano-crystalline diamond (NCD) films grown with RayND precursor exhibit a high level of quality.
Scanning Electron Microscopy (SEM) image of diamond
Fig.1 Scanning Electron Microscopy (SEM) image of diamond film of 500 nm thickness grown on silicon with ASTEX 1.5 KW microwave plasma deposition system using RayND precursor for initial nucleation.
 Atomic Force Microscope (AFM) image
Fig. 2. Atomic Force Microscope (AFM) image, scan size = 10 nm
The measured surface roughness: RMS 12.1 nm.

Raman shifts of 2 μm NCD layers on SiO2 obtained with RayND and DND precursors.
Raman shifts of 2 μm NCD layers on SiO2 obtained with RayND and DND precursors.
Fig. 3. Raman shifts of 2 μm NCD layers on SiO2 obtained with RayND and DND precursors.
Diamond peak observed at 1332 cm-1.
sp2 hump presents at around 1560 cm-1.
Si peak from SiO2 substrate appears at 504 cm-1.
At RayND shift (blue) the diamond peak is higher than the Si peak, while at DND shift (red) the diamond peak is lower than the Si one.

NCD/n-Si heterojunctions were characterized by current - voltage (I-V) for both kinds of synthesized films at 250.
NCD/n-Si heterojunctions were characterized by current - voltage (I-V) for both kinds of synthesized films at 250.
Fig. 4. NCD/n-Si heterojunctions were characterized by current - voltage (I-V) for both kinds of synthesized films at 250.
Current of RayND (blue) is higher than that of DND (red), perhaps due to metal impurities in DND seeds.
Ray Techniques fabricates highly concentrated and well dispersed nanodiamond suspensions in Isopropyl Alcohol for CVD seeding applications.