Title :
Two-dimensional spatial profiles of size and density of particulates grown in RF silane plasmas
Author :
Shiratani, Masaharu ; Kishigaki, Nobuhiro ; Kawasaki, Hiroharu ; Fukuzawa, Tsuyoshi ; Watanabe, Yukio
Author_Institution :
Dept. of Electr. Eng., Kyushu Univ., Fukuoka, Japan
fDate :
2/1/1996 12:00:00 AM
Abstract :
Two-dimensional (2-D) spatial profiles of size and density of particulates in RF silane plasmas have been measured simultaneously using a newly developed in situ polarization-sensitive laser light scattering method. Particulates are observed principally in the annular region, around the plasma/sheath boundary near the RF electrode. Their size and density are in ranges of 50~110 nm and 106~108 cm-3, respectively. Furthermore, larger particulates tend to be localized nearer to the RF electrode and to about 10 mm off the discharge-column-axis. The observed profiles of particulates along the discharge-column-axis can be explained by a balance between electrostatic and ion drag forces exerted on them. Their annular radial profiles may be explained by taking into account that the ion density has the radial distribution, and the electric field around the plasma/sheath boundary has the radial component
Keywords :
ion density; light scattering; plasma density; plasma diagnostics; plasma impurities; plasma sheaths; silicon compounds; 50 to 110 nm; RF SiH4 plasmas; RF electrode; SiH4; annular radial profiles; discharge-column-axis; electrostatic forces; in situ polarization-sensitive laser light scattering method; ion density; ion drag forces; particulate density; particulate growth; particulate size; plasma/sheath boundary; two-dimensional spatial profiles; Density measurement; Electrodes; Optical polarization; Particle measurements; Plasma density; Plasma measurements; Plasma sheaths; Radio frequency; Size measurement; Two dimensional displays;
Journal_Title :
Plasma Science, IEEE Transactions on
