The mechanisms of bias enhanced nucleation (BEN) of diamond on silicon
substrates are investigated by means of electrical measurements, OES
investigations, and macroscopic as well as local characterization of B
EN films. Based on electrical investigations we propose that the repro
ducibility and homogeneity problems often found in BEN are caused by d
iamond coated surfaces in the vicinity of the substrate. We further sh
ow that tile nucleation enhancement does not rely on changes in gas ph
ase chemistry but rather on direct bombardment of the surface by ions
with a mean energy of about 15 to 20 eV. The influence of bias voltage
, carbon concentration in the gas phase: and substrate temperature on
the nucleation process is investigated. Finally, the Films obtained by
BEN are investigated by FTIR and stress measurements. A nucleation se
quence (SiC formation: deposition of a hydrocarbon film, formation of
diamond and simultaneous development of stress) is established and com
pared with SEM images of the Films. The role of each step of the seque
nce is discussed in detail.