No abstract

In this study, the effect of deposition conditions and the temperature thermal treatment on the oxide parameters of two structures of silicon layers were investigated. The study present the evolution of boron profiles following a dry thermal oxidation in poly-Si/SiO2/c-Si films deposited at 520°C and 605°C temperatures and thermally oxidized in dry oxygen at respectively temperature 840°C, 945°C and 1050°C for tr=1h33’duration. The results show that the deposition conditions and the temperature treatment make a very important impact on the obtained films, which affect the redistribution and localization of dopants. It has been observed that the obtained value of the linear and the parabolic rate constant, the diffusion coefficient and the oxidation thickness are higher in the films deposited at Td = 520°C than those deposited at Td = 605°C. Also, the X-ray diffraction is strongly affected by the oxide thickness deposited between poly-silicon layers and crystalline substrates.

In this study, the effect of deposition conditions and the temperature thermal treatment on the oxide parameters of two structures of silicon layers were investigated. The study present the evolution of in situ boron profiles following a dry thermal oxidation in poly-Si/SiO2/c-Si films deposited at 520°C and 605°C temperatures and thermally oxidized in dry oxygen at respectively temperature 840°C, 945°C and 1050°C for duration tr=1h33’. The results show that the deposition conditions and the temperature treatment make a very important impact on the obtained films, which affect the redistribution and localization of dopants. It has been observed that the obtained value of the linear and the parabolic rate constant, the diffusion coefficient and the oxidation thickness are higher in the films deposited at Td = 520°C than those deposited at Td = 605°C. Also, the X-ray diffraction is strongly affected by the oxide thickness deposited between poly-silicon layers and crystalline substrates.

This work studies the effect of carrier trapping and the recombination activity at the grain boundaries in the p-layer of polysilicon solar cells with respect to the deposition temperature. The dependence of the grain size on the deposition temperature was studied in different samples of boron-doped low-pressure chemical vapor deposition (LPCVD) silicon deposits, conducted in a horizontal low-pressure atmospheric pressure reactor where the temperature varied over a range from 520 °C to about 605 °C. The obtained results show clear evidence of dependence on effective changes in the trapping effect as a function of the trapping density states, the doping level and the thickness dimension of the deposited layer.

In this work, a representative graphical method was used to estimate the potential barrier at grain boundaries in polycrystalline materials. The used equation for the determination of trapping density states is closely related to the doping concentration in the layer. The obtained results showed that this density is a crucial parameter for estimating the maximum barrier value. This parameter strongly depends on the grain size and, consequently, on the grain boundary width. The conduction (or transport) properties represented by the thermionic current and the effective mobility also prove this dependence. Also, the obtained results are in good agreement with the experientially measured values from previous works.