Silicon powder has been produced by means of square-wave modulated rf silane plasma. The plasma conditions were: 30°C of reaction chamber temperature, 70 Pa of pressure, 80 W of rf power and 0. 1 Hz of square-wave modulation frequency. The gas flow rate was varied from 5 to 90 sccm.
The distribution and size of the powder grains were determined by transmission electron microscopy. The compositional and microstructural analysis of the powder was performed by FTIR spectroscopy. This analysis has revealed the dominant presence of SiH2 groups (2100 cm−1), in a highly polymeric form (850 and 890 cm−1), as well as the existence of an absorption band (1000-1100 cm−1) associated with oxidation of the powder.
These results have shown the great influence of the flow rate, through the gas residence time, on the composition and microstructure of silicon powder.