Growth of silicon nanoclusters on different substrates by plasma enhanced chemical vapor deposition.
We report an atomic force microscopy study of the early stages of growth of silicon nanoclusters formed on different substrates by plasma-enhanced chemical vapor deposition, using dichlorosilane (SiH2CI2) and hydrogen (H2) as reactive gases. (100) n-type single crystalline silicon, fused silica, amorphous silicon nitride and corning glass, were used as substrates for the growth of the nanoclusters, which were formed at low substrate temperature (200 degrees C). The diameter, height and number density of the clusters were controlled by the deposition time and pressure. It was found that not only the plasma conditions but also the surface characteristics of the substrate influence the cluster density, shape, and size. For the ordered silicon surface and the amorphous fused silica, the nanoclusters result oval in shape and exhibit preferential growth along the surface. When deposited over amorphous silicon nitride and corning glass, the density of nanoclusters increases and there is a tendency toward columnar growth since the diameter of the nanoclusters tends to decrease. We conclude that although the specific features of the nanoclusters originate from the chlorine chemistry introduced by the SiHxCly deposition precursor and the chemical stability of chlorine-terminated surfaces under hydrogen plasma, the surface quality and roughness also plays an important role on the nucleation and mobility of the species. The combination of both effects gives rise to the different nanostructured growths observed.
Monroy
B M
BM
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Cd. Universitaria, A.P 70-360, Coyoacán 04510, D.F México.
Santana
G
G
Fandiõ
J
J
Ortiz
A
A
Alonso
J C
JC
D000327:Adsorption; D003460:Crystallization / Q000379:methods*; D005740:Gases / Q000737:chemistry; D006358:Hot Temperature; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008567:Membranes, Artificial; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D012821:Silanes / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
D005740:Gases; D046911:Macromolecular Substances; D008567:Membranes, Artificial; D012821:Silanes; C005625:monosilane; D012825:Silicon