Y. Takamura et al., CLUSTER-SIZE MEASUREMENT USING MICROTRENCH IN A THERMAL PLASMA FLASH EVAPORATION PROCESS, Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena, 15(3), 1997, pp. 558-565
Soft-vacuum plasma processes have been increasing in importance for hi
gh-quality, large-area, and high-rate fabrication of thin films for pr
actical applications. In such processes, the characteristics of the de
posited species (considered to be clusters) have been of interest. How
ever, even their size has not been sufficiently investigated because o
f the many difficulties arising due to the high pressure conditions an
d the steep temperature and concentration gradients in the boundary la
yer, especially when the species change easily during measurements. In
this work, we describe a new method of using a microtrench, to determ
ine the mean cluster size d(c), diffusivity D, and sticking probabilit
y eta without any disturbances to the plasma or the boundary layer con
ditions. Using this method, the cluster size in the deposition of YBa2
Cu3O7-x high-T-c superconductor by plasma flash evaporation is success
fully measured as 1-9 nm, with the parameters of source powder feeding
rate from 60 to 350 mg/min, torch substrate distance from 270 to 360
mm in 200 Torr, 50 kW 95%O-2-5%Ar inductively coupled rf plasma. (C) 1
997 American Vacuum Society.