E. Mateeva et P. Sutter, Influence of the substrate bias on epitaxial growth of Si films by dc-discharge plasma chemical vapour deposition, SEMIC SCI T, 13(12), 1998, pp. 1426-1430
We report on the investigation of the influence of the substrate bias on th
e structure of epitaxial Si films grown on Si (100) by low-energy de-discha
rge plasma enhanced chemical vapour deposition in the temperature range bet
ween 410 degrees C and 600 degrees C. The effect of the substrate bias was
studied by reflection high-energy electron diffraction, cross-sectional tra
nsmission electron microscopy (XTEM) and scanning tunnelling microscopy (ST
M). The XTEM investigations showed that the Si films grown at a negative su
bstrate bias below 10 V are of good quality and defect free. In the films g
rown at a higher negative substrate bias a critical thickness was observed
up to which the films remain free of extended defects. This critical thickn
ess was found to be related to the ion bombardment of the surface during gr
owth and to be substrate temperature dependent. The STM studies showed that
the nucleation of stacking faults at this critical thickness is connected
to an evolution of the surface roughness and a change of the growth mode fr
om two- to three-dimensional at ion energies above 10 eV.