K. Goshima et al., Lower temperature deposition of polycrystalline silicon films from a modified inductively coupled silane plasma, JPN J A P 1, 38(6A), 1999, pp. 3655-3659
An inductively coupled plasma (ICP) is successfully modified to deposit pol
ycrystalline silicon (poly-Si) films on a glass substrate (< 300 degrees C)
with SiH4 diluted by hydrogen. The modification includes a gas residence t
ime control and a dielectric cover on an internal metal antenna. A metal an
tenna discharge in 2% SiH4 at a total pressure of 2.0 Pa results in a monot
onically increasing deposition rate up to 0.4 nm/s with a decrease in the r
esidence time to 18 ms. The dielectric-covered antenna makes the deposition
rate two times higher than the metal antenna. The higher crystallinity of
the deposited film is achieved with a lower residence time and/or a smaller
percentage of SiH4: both of which decrease the deposition rate. For exampl
e, a 600W 0.3% SiH4 discharge by the dielectric cover antenna gives a poly-
Si grain size of 140 nm fi om the X-ray diffraction (XRD) spectra and a cry
stallization factor of 0.98 from the Raman spectra.