The atomic layer control of SiO2 growth can be accomplished using bina
ry reaction sequence chemistry. To achieve this atomic layer growth, t
he binary reaction SiCl4 + 2H(2)O --> SiO2 + 4 HCl can be divided into
separate half-reactions: (A) Si-OH + SiCl4 --> SiO-Si-Cl-3* + HCl, (
B) Si-Cl + H2O --> Si-OH* + HCl, where the asterisks designate the su
rface species. Under the appropriate conditions, each half-reaction is
complete and self-limiting and repetitive ABAB... cycles should produ
ce layer-by-layer-controlled SiO2 deposition. The atomic layer growth
of SiO2 thin films on Si(100) was achieved tit temperatures from 600-6
80 K with reactant pressures from 1-50 Torr. These experiments were pe
rformed in a small high pressure chamber situated in an ultrahigh vacu
um (UHV) apparatus. This design couples high pressure conditions for f
ilm growth with an UHV environment for surface analysis using laser-in
duced thermal desorption (LITD), temperature-programmed desorption (TP
D) and Auger electron spectroscopy (AES). The controlled growth of a s
toichiometric and chlorine-free SiO2 film on Si(100) was demonstrated
using these techniques. SiO2 growth rates of approximately 0.73 ML of
oxygen (1.1 Angstrom of SiO2) per AB cycle were obtained at 600-680 K.
Additional vibrational spectroscopic studies performed in a second va
cuum chamber utilized transmission Fourier transform infrared (FTIR) e
xperiments on high surface area, oxidized porous silicon to monitor th
e surface species during the binary reaction sequence chemistry. These
FTIR measurements observed the Si-Cl stretching vibration at 625 cm(-
1) and the SiO-H vibration at 3740 cm(-1) and confirmed that each half
-reaction was complete and self-limiting. These studies illustrate the
feasibility of atomic-layer-controlled SiO2 growth and have determine
d the reactant pressures and substrate temperatures required for the S
iO2 binary reaction sequence chemistry.