S. Terakado et al., SYNCHROTRON RADIATION-ASSISTED ETCHING OF SI IN THE PRESENCE OF REACTIVE SPECIES PRODUCED BY MICROWAVE-DISCHARGE, Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena, 11(5), 1993, pp. 1890-1894
The photochemical etching of Si has been studied using synchrotron rad
iation (SR) in the presence of reactive species produced by 2.45 GHz m
icrowave discharge in a mixture of SF6 and Ar. The effect of SR irradi
ation was investigated, and it was found that the SR-irradiated region
was etched at a rate one order of magnitude faster than was the nonir
radiated region. A clear fringe pattern appeared parallel to the edge
of the replicated mask pattern on the Si surface. These fringes were i
nterpreted as caused by the diffraction effect of the incident beam at
the mask. By comparing the etched fringe pattern with the calculated
one of the Fresnel diffraction, it was clarified that the etched patte
rn agreed with the diffraction one. That is, the spatial distribution
of the photointensity was replicated on the etched surface. Therefore,
it was concluded that the main effect of SR irradiation was to activa
te the etching reaction on the sample surface.