A high-sensitivity photon-counting laser-light-scattering method is applied to obtain information on initial growth of particles formed in low pressure and low power GeH4 RF discharges. Particles of about 1 nm in size are detected principally around the plasma/sheath boundary near the RF electrode at an early time of 0.2 s after the discharge initiation and the corresponding particle density of 2 × 1011 cm-3 is about two orders of magnitude higher than ion density. Spatial profiles of particle amount are very similar to those of Ge emission intensity, which indicates a radical production rate. These results suggest that short-lifetime radicals such as GeH2, having a high production rate, are candidates for key species contributing to the nucleation and initial growth of particles, even for a low pressure (8-13 Pa) and a low power density (0.04 W/cm2). Furthermore, surface reflection probabilities of particles 1-12 nm in size, measured after RF-power-off, are found to be more than 80%.
|Journal||Japanese Journal of Applied Physics, Part 2: Letters|
|Issue number||10 SUPPL. B|
|Publication status||Published - Oct 15 1998|
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)
- Physics and Astronomy(all)