Measurement of ion energy distributions in the bias enhanced nucleation of chemical vapor deposited diamond

Abstract

In situ, real-time, mass selective energy analysis of the incoming ions has been carried out during bias enhanced nucleation for diamond chemical vapor deposition. The dependence of ion energies and fluxes as a function of the bias voltage and CH4 concentration was measured. The main ionic species that strike the substrate surface during bias enhanced nucleation have energies between 50 and 80 eV and are characterized by a low H content. When the bias is lowered to the value at which nucleation enhancement becomes negligible (100 V in our system), ions have an energy of about 30–40 eV, which is the critical value for penetrating below the surface of a hydrogenated amorphous carbon layer. These findings strongly support the subplantation model of bias enhanced nucleation.

Diamond Nucleation and Seeding Techniques: Two Complementary Strategies for the Growth of Ultra-thin Diamond Films

“…100 The second pertinent parameter to consider is the ion flux, which bombards the surface. According to Kátai et al 99 it is closely related to the bias voltage and the methane content ( Figure 10.7).…”

“…Indeed, the energy provided by the bias voltage is not totally transferred to the positively charged species as reported in the literature. 99,100 On the other hand, the kinetic energy of accelerated H y 1 and C x H y 1 ions is a critical parameter. In situ, real-time, mass-selective energy analysis of the incoming ions has been carried out during BEN by Kátai et al 99 For example, the ion energy distributions were measured for a bias voltage of :200 V and a methane content of 4%.…”

Study on formation and shape of carbon nanotips depending on ion bombardment

“…In Ref. [14], the energy of hydrogen and methane ions in the CH 4 -H 2 plasma at the bias of 200 V is about 80 and 32.5 eV when the content of methane is 8% and the energy is not greatly changed with increasing of the content of methane, which the plasma is produced at 2.5 Â 10 3 Pa and 800 8C. By these data and the conditions in the experiments, it can be speculated that the energy of hydrogen and nitrogenous ions are over 80 and 32.5 eV in the process of growing the carbon nanotips when the bias is over 300 V, respectively.…”

“…From Table 1, the bias is increased with increasing of the bias current. Thus, the ion energy is increased [14] and that the reaction of the hydrogen and nitrogenous ions with the hydrogen atoms in the surface of the carbon film is improved. By the formation condition of the carbon nanotips, Eq.…”

Effects of the bias enhanced nucleation hot-filament chemical-vapor deposition parameters on diamond nucleation on iridium

“…Contrary to MWCVD, 23 the HFCVD technique provides less atomic hydrogen and less ionic species. Consequently, a glow discharge is hardly stable under usual experimental conditions.…”