Effective silicon production from SiCl₄ source using hydrogen radicals generated and transported at atmospheric pressure

Figures & data

Figure 1. Schematic of an apparatus for H-radical generation and transportation.

Figure 2. Schematic of (a) the apparatus used for reduction of SiCl₄ and (b) the position of the quartz glasses.

Table 1. Pressures of generation and detection chambers.

Generation chamber (kPa)	Detection chamber (kPa)	Difference between two chambers (kPa)
10	9	1
20	19	1
40	38	2
60	58	2
80	78	2
101	98	3
105	101	4

Figure 3. Dependence of the estimated H-radical density on (a) the pressures in the H-radical generation chamber and the detection chamber (the pressures represented in the graph are the pressures in the detection chamber), (b) currents applied to the W filaments (the temperatures indicated in the graph are estimated W filament temperatures), and (c) the transportation distance.

Figure 4. (a) Appearance of quartz tubes and quartz glasses after the reduction of SiCl₄. (b) XRD pattern and (c) cross-sectional SEM image of the quartz glass placed at the position B during the experiment with an applied current of 30 A. The pressure in the H-radical generation chamber and the reaction chamber were ~3 kPa and ~1.8 kPa, respectively.

Figure 5. Appearances of quartz tubes and quartz glasses after the reduction of SiCl₄ with H₂ and H-radicals at 900°C, and cross-sectional SEM images of the quartz glasses placed at position B. The pressures in the H-radical generation chamber and the reaction chamber were ~105 kPa and ~101 kPa, respectively.

Figure 6. (a) Appearances of the quartz tubes and quartz glasses after the reduction of SiCl₄ with H₂ and H-radicals at 850°C, and cross-sectional SEM images of the quartz glasses placed at positions A–D. (b) XRD pattern and (c) Raman spectrum of the quartz glass placed at position D during the H-radical reduction of SiCl₄. The pressures in the H-radical generation chamber and the reaction chamber were ~105 kPa and ~101 kPa, respectively.