Nucleation behaviour of diamond particles on silicon substrates in a hot-filament chemical vapour deposition

Studies on nucleation process in diamond CVD: an overview of recent developments

“…The precursors are adsorbed on the substrate mainly by physical adsorption below 900 ˚C and predominantly by chemical adsorption above this temperature, resulting in an abrupt increase in the diffusion length of the precursors around 900 ˚C [96]. As a result, the capture rate of the precursors (sticking probability) on the substrate surface, and hence the nucleation rate and density, drastically increase when the substrate temperature approaches 860 C. [18] Suppresses nucleation [17] Decreases nucleation density, 33% O 2 [133] 0.75-0.9 O 2 /C 2 H 2 [21] The effect of filament temperature in HFCVD on nucleation is similar to that of substrate temperature, i.e., with increasing filament temperature, nucleation density initially increases, reaches a maximum at 2100 ˚C and decreases thereafter, with 2100 ˚C being a possible optimum value [43]. The drop-off for T > 2100 ˚C is explained by the observation that the etching of nucleation sites is enhanced with increasing filament temperature [47].…”

“…Nucleation density has been increased from <10 5 cm -2 on untreated substrates up to 10 11 cm -2 on scratched or biased substrates [39,40]. The effects of surface conditions and deposition parameters on the nucleation process have been investigated [12,16,18,21,[41][42][43][44][45][46][47][48][49][50] to provide the guideline for the selection of optimum surface pretreatment methods and deposition parameters. Recent advances in experimental measurement methods make it possible to directly observe the nucleation stage, and in some cases in-situ and/or in vacuo measurements [23,40].…”

A review of nucleation, growth and low temperature synthesis of diamond thin films

“…The nucleation density increased with increasing filament temperature, reached the maximum at 2100uC and then decreased thereafter in HFCVD. 112 The decreased nucleation beyond 2100uC was attributed to the enhanced etching of the nucleation sites. A number of examples of enhanced nucleation with temperature are found in for different deposition methods and an optimum temperature has been found to exist y860uC where the nucleation density becomes maximum.…”

Diamond growth on faceted sapphire and the charged cluster model

“…The atomic hydrogen from the dissociation of molecular hydrogen is actively involved in the etching process of non-diamond carbon and thus could also be the cause of the observed etch pits on the sapphire surface. Park and Lee [12] attributed the formation of etch pits on mirror-polished silicon substrates to the process of etching by atomic hydrogen. Thus, the observation of etch pits on the substrate surface suggests that atomic hydrogen is involved in the etching of the sapphire substrate [13].…”