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We investigated the post-deposition heating (PDH) effect on OH content in SiOx films deposited by atmospheric-pressure CVD using a deposition source of silicone oil (SO) with O3 and TCE vapor at a temperature Td of 180 °C–250 °C. The PDH is performed in situ for 5 min in the deposition chamber just after film deposition without any supply of SO, where the heating temperature is the same as Td. The OH content in the films deposited normally decreases with increasing Td. In contrast, those with PDH decrease with deceasing Td from 220 °C, and, at Td = 190 °C, a minimum OH content can be obtained. This means that lower OH content remains at a lower deposition temperature. The PDH effect on OH reduction can be explained by easily reconstructible structure of SiOx films deposited at low temperature. Furthermore, we discuss the mechanism of the PDH effect from other points of view.

We investigated the dependences of the deposition rate and residual OH content of SiO_2 films on the concentration of trichloroethylene (TCE), which was added during deposition at low temperatures of 160-260 °C with the reactant gases of silicone oil (SO) and O_3. The deposition rate depends on the TCE concentration and is minimum at a concentration of ~0.4 mol/m^3 at 200 °C. The result can be explained by surface and gas-phase reactions. Experimentally, we also revealed that the thickness profile is strongly affected by gas-phase reaction, in which the TCE vapor was blown directly onto the substrate surface, where it mixed with SO and O_3. Furthermore, it was found that adding TCE vapor reduces residual OH content in the SiO_2 film deposited at 200 °C because TCE enhances the dehydration reaction.

A low-temperature silcon oxide film was deposited at 160 to 220 °C using an atmospheric pressure CVD system with silicone oil vapor and ozone gases. It was found that the deposition rate is markedly increased by adding trichloroethylene (TCE) vapor, which is generated by bubbling TCE solution with N_2 gas flow. The increase is more than 3 times that observed without TCE, and any contamination due to TCE is hardly observed in the deposited Si oxide films from Fourier transform infrared spectra., identifier:https://dspace.jaist.ac.jp/dspace/handle/10119/15344

Amorphous Si thin films on yttria-stabilized zirconia (YSZ) layers were crystallized widely in solid phase by the two-step method with a pulsed laser, moving the sample stage. The crystalline quality, impurity diffusion, and electrical properties of the crystallized Si films were investigated. It was found that the crystallinity of the Si thin films was improved and their surface was smooth without an incubation layer at the interface, indicating the uniform crystallinity of Si on YSZ. The diffusion of Zr and Y into the Si thin films was as small as or smaller than the order of 1017 atoms/cm3. We evaluated the electrical properties of carrier concentration and Hall mobility of the Si thin films with/without YSZ layers by using the resistivity and AC Hall effect measurements. The temperature and doping concentration dependences were measured for both undoped and P-doped films. It was found that both the undoped and P-doped Si/YSZ/glass films showed higher mobilities and carrier concentrations (and therefore higher conductivities), which indicate a smaller number of defects, than the Si/glass films. This suggested that the Si film crystallized on the YSZ layer is more suitable for application to electronic devices than the Si film on glass.

Crystalline quality of pulse-laser annealed micocrystalline silicon (poly-Si) films on yttria-stabilized zirconia [(ZrO_2)_<1-x>(Y_2O_3)_x: YSZ] crystallization-induction (CI) layers is further improved by a new two-step irradiation method, in which amorphous silicon (a-Si) films are irradiated using two kinds of energy density. Firstly, they were irradiated at a low energy density for a short time to generate nuclei, following by irradiation at a high energy density to complete crystallization. Crystalline fraction and grain size of the Si film crystallized by the two-step method were found to be larger while its FWHM was smaller than those by the conventional one. Moreover, grain size of the Si/YSZ/glass was more uniform than that of the Si/glass. This indicates not only effectiveness of the YSZ CI layer but also usefulness of the two-step method on improving Si film quality., identifier:https://dspace.jaist.ac.jp/dspace/handle/10119/12612

We investigated the crystallization-induction (CI) effect of yttria-stabilized zirconia (YSZ) on the solid phase crystallization of amorphous Si (a-Si) films. The incubation time τ_i for crystallization on a polycrystalline YSZ layer was shorter than that on a glass substrate. From the result of Arrhenius plots of 1/τ_i, it is suggested that the CI effect is not due to the difference in the activation energy E_i but to a higher nucleation site area density on the YSZ layer. Also, preheating the YSZ layer prior to a-Si film deposition was effective to shorten the incubation time τ_i because E_i was reduced.

The solid-phase crystallization of amorphous Si films with/without a crystallization-induction (CI) layer of yttria-stabilized zirconia (YSZ) was performed using a Nd:YAG pulse laser. We investigated the crystallinity of the Si films by Raman spectroscopy. It was found that, at the same crystalline fraction, the FWHM of the c-Si peak for Si/YSZ/glass was smaller than that for Si/glass. The result is considered owing to the CI effect of the YSZ layer. This was confirmed by scanning electron microscopy observation, which showed that the grain size of Si on YSZ layers was more uniform than that on glass substrates. On the other hand, at a lower beam energy, the crystalline quality of the Si films was found to be better although the increase in the crystallization rate with the pulse number N is smaller. On the basis of the above results, the crystallization model of an a-Si film on a YSZ layer is speculated., identifier:https://dspace.jaist.ac.jp/dspace/handle/10119/11938

Si films were deposited at low temperatures on glass substrates covered with poly-yttria-stabilized zirconia (YSZ) layers. We investigated the dependences of crystallization on the Y content and cleaning solution for the YSZ layers. Transmission electron microscopy showed that some regions of the Si film deposited at 430 °C were directly crystallized on a YSZ layer without an amorphous region, where Si lattice fringes were tightly connected to YSZ lattice fringes. The crystallization of Si films on YSZ layers occurred at deposition temperatures lower than that on glass substrates by more than 100 °C. Zr, Y, and F concentrations in the Si film were negligible, except the Zr concentration near the interface. The discussion on the crystallization mechanism gave the following suggestions on the method of obtaining a high crystalline fraction. The YSZ layer should be chemically cleaned using a solution containing HF before Si film deposition, and the content ratio Y/(Zr+Y) of YSZ should be ≳ 0.2., identifier:https://dspace.jaist.ac.jp/dspace/handle/10119/9218