Setsuo Nakajima

Incubation-Free Growth of Polycrystalline Si Films by Plasma-Enhanced Chemical Vapor Deposition Using Pulsed Discharge under Near Atmospheric Pressure

By using the plasma-enhanced chemical vapor deposition (PE-CVD) under near-atmospheric pressures, we have achieved a high rate growth, 1 nm/s, of polycrystalline Si films on glass substrates without incubation layers for the first time. We have employed a short-pulse based system for a stable operation of discharge at atmospheric pressures without inert gas dilution. This feature enabled us to employ an extremely high dilution of monosilane by hydrogen, which should be the origin of the incubation-free growth of our films, in addition to the basic advantage for the high rate growth inherent in atmospheric reaction systems. The films are mainly consisted of polycrystalline Si with grain size ranging from 5 nm to above 10 nm, as observed by Raman scattering, X-ray diffractions and cross sectional transmission electron microscopy.

Low Temperature Deposition of Si-based Thin Films on Plastic Films Using Pulsed-Discharge PECVD under Near Atmospheric Pressure

Low temperature (150 °C) deposition of doped and undoped polycrystalline Si (poly-Si) as well as SiN X films on polyethylene terephthalate (PET) films has been achieved with practical deposition rates by using pulsed-plasma CVD under near-atmospheric pressure. The precursor is SiH 4 diluted in H 2 for poly-Si while N 2 has been additionally used for SiN x . No inert gases such as He was used. A short-pulse based power system has been employed to maintain a stable discharge in the near-atmospheric pressures. With this technique, deposition of poly-Si thin film with virtually no incubation layer is possible, which in the case of P-doped poly-Si shows a Hall mobility (μ H ) of 1.5 cm 2 /V·s.