Papers by Keyword: Trichlorosilane

Abstract: Preliminary results of 150mm SiC 4H 4°off have been obtained with the new 150mm automatic horizontal hot wall reactor PE1O6, using chlorinated chemistry (SiHCl₃ + C₂H₄). A new injection system has been tested in two configurations and results will be shown in this paper. AFM surface roughness measurements and epi defect density have been reported.

Abstract: In order to reduce the production cost of polysilicon, the raw material of the photovoltaic industry, applying heat integrated distillation technology of two towers in trichlorosilane distillation process consisting of removal of light components after removing heavy components. By assistant of a chemical process software, the new energy-saving process is simulated, the main parameters of two towers are optimized and the best implementation solution are provided. The optimum parameters for the first tower are the operation pressure of 500 kPa, the number of theoretical plates of 32, the position of feed plate of 24, reflux ratio of 4.2 and the distillate to feed ratio of 0.8516. For the second tower, the operation pressure, the number of theoretical plates, the position of feed plate, the reflux ratio and the bottoms to feed ratio are 250 kPa, 74, 15, 111 and 0.9652 respectively.The results showed that the new process can save energy consumption up to 50%, the coefficient of recovery for trichlorosilane is up to 98.7% while the high purity of trichlorosilane can ensure the resulted polysilicon excellent photovoltaic properties.

Abstract: The new two-tower process of thrichlorosilane distillation consisting of removal of light components after removing heavy components is analyzed by assistant of a chemical process simulation software. In order to achieve lower energy consumption, the parameters for each tower in the new process are optimized, such as the number of theoretical plates, the position of feed plate, reflux ratio and distillate (bottoms) to feed ratio. The results show that the optimum parameters for the first tower are the number of theoretical plates of 32, the position of feed plate of 24, reflux ratio of 2.5 and the distillate to feed ratio of 0.8516. For the second tower, the number of theoretical plates, the position of feed plate, the reflux ratio and the bottoms to feed ratio are 80, 16, 143 and 0.9652 respectively. Applying the optimized results in practical production, mass fraction of PCl3 in overhead of the first tower is reduced by two orders of magnitude, condenser duty and reboiler duty of the second tower are dropped by more than eight percent while obtaining higher purity trichlorosilane products.

Abstract: 4H-SiC epitaxial growth on 2˚ off-axis substrates using trichlorosilane (TCS) is presented. Good surface morphology was obtained for epilayers with C/Si ratios of 0.6 and 0.8 at a growth temperature of 1600°C. The triangle defect density was reduced to a level below 5 cm^-2 at 1600°C and below 1 cm^-2 at 1625°C for a C/Si ratio of 0.8. Photoluminescence (PL) measurements were carried out with band-pass filters of 420 nm, 460 nm, and 480 nm to detect stacking faults. A stacking fault density of below 5 cm^-2 was achieved at 1600°C and 1625°C with a C/Si ratio of 0.8. The optimal conditions for TCS growth were a C/Si ratio of 0.8 and a growth temperature of 1600°C. The evaluation of stacking faults and etch pit density indicated that the use of 2˚ off-axis substrates and TCS is effective for reducing basal plane dislocations. Comparing these results to those using silane (SiH₄) with HCl added, it was demonstrated that TCS is much more suitable for obtaining high-quality epilayers on 2º off-axis substrates.

Abstract: A process has been developed to grow multi-epy high doped structure. Trichlorosilane (TCS) and Ethylene have been used as precursor; Nitrogen (N2) and trimethylaluminum (TMA) as doping source. The SIMS and SCM analysis show that using this silicon precursor very abrupt N++/P+/N+ junctions (40-60 nm) can be obtained with low background doping concentration in a single epitaxial growth run.

Abstract: The growth rate of 4H-SiC epi layers has been increased up to 100 µm/h with the use of trichlorosilane instead of silane as silicon precursor. The epitaxial layers grown with this process have been characterized by electrical, optical and structural characterization methods. Schottky diodes, manufactured on the epitaxial layer grown with trichlorosilane at 1600 °C, have higher yield and lower defect density in comparison to diodes realized on epilayers grown with the standard epitaxial process.

Abstract: The aim of this work is to improve the heteroepitaxial growth process of 3C-SiC on Si substrates using Trichlorosilane (SiHCl3) as the silicon growth precursor. With this precursor it has been shown that it is possible to simultaneously increase the growth rate of the process and avoid the nucleation of silicon droplets in the gas phase. Growth experiments were conducted on three (3) Si substrate orientations in order to assess the impact of the Si substrate on the resulting 3C-SiC film. X-ray Diffraction (XRD), Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM) analysis show the important role of the substrate orientation for the growth process. The different orientation of the substrate modifies the morphology of the 3C-SiC crystalline structure, mostly by changing the density of micro-twins and stacking faults inside the film.