Amorphous SiO 2 (a-SiO 2 ) films were deposited at 300 • C by plasma-enhanced chemical vapor deposition using SiH 4 -O 2 mixtures. The [O 2 ]/[SiH 4 ] ratio was maintained at 1.5, in which oxide films having a stoichiometric composition could be obtained. The Si-O-Si stretching mode, stress, the density of Si dangling bonds and buffered HF (BHF) etch rate were investigated as a function of film thickness. It was found that the peak frequency of Si-O-Si stretching mode centered at around 1050 cm −1 increased from 1050 to 1075 cm −1 with increasing film thickness from 0.1 to 1.1 µm. By comparison with calculations based on the effect of multiple reflections in film/substrate system, it was found that the shift of the Si-O-Si stretching mode to high frequencies was due not only to the effect of multiple reflections, but also to the physical effect of thermal heating and/or ion bombardment during film growth, which would contribute to rearrangement of the Si-O-Si bonding network. The experimental results for the stress behavior, the density of Si dangling bonds and BHF etch rate confirmed this finding.

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Decorated stacking faults in (100) silicon were distinguished from clean faults by Sirtl etch at any etching stage. The decorated faults were delineated as hillocks, while the clean faults were delineated as flat and geometric pit‐features by Sirtl etch. These observations were confirmed by transmission electron microscopy. The formation of the different etch features of the faults can be explained in terms of the solution etch rate and the activity of the etch agent on the decorating precipitates.

The temperature rise of an X-ray mask irradiated by synchrotron radiation (SR) emitted from the SORTEC storage ring has been measured in situ using the thermography technique. In order to detect IR rays in the range of 2.5-5.6 µ m wavelength, emissivities for masks with and without an absorber were measured in advance by using Fourier transform infrared spectroscopy. After measuring the temperature rise of the mask as a function of helium (He) pressure, the heat transfer coefficient was analyzed for estimating the thermal effect on the mask-wafer assembly. Using this heat transfer coefficient, the temperature rises of 20 and 0.3° C in vacuum and under atmospheric He pressure were successfully calculated at a ring current of 200 mA, respectively. The He pressure above 10 Torr in the exposure chamber is sufficient in SR lithography to minimize the temperature rises of the mask membrane and wafer.

Temperature rises in a wafer and an X-ray mask membrane have been investigated by means of synchrotron radiation (SR) lithography, using, respectively, experimental and theoretical methods. When considering temperature rise in an X-ray mask, the wafer has been assumed to act as a heat-sink during exposure. In-situ temperature measurement was performed using a wafer with an embedded thermocouple at a 200 mA beam current. The temperature rise to be measured was simulated by a heating model based on a lumped heat capacity system. It was found that SR exposure increased the wafer temperature as well as that of the X-ray mask membrane. The assumption that the wafer acts as a heat-sink during exposure is not valid. The mask temperature rise of ∼0.3°C is estimated from the wafer temperature measurement.