Furnace for continuous, high throughput diffusion processes from various diffusion sources

摘要

An open apparatus is described for the processing of planar thin semiconductor substrates, particularly for the processing of solar cells. The apparatus includes a first zone for the drying and burn-out of organic components from solid or liquid based dopant sources pre-applied to the substrates. The zone is isolated from the remaining zones of the apparatus by an isolating section to prevent cross-contamination between burn-out zone and the remaining processing zones. All the zones of the apparatus may be formed from a quartz tube around which heaters are placed for raising the temperature inside the quartz tube. Each zone may be purged with a suitable mixture of gases, e.g. inert gases such as argon, as well as oxygen and nitrogen. The zones may also be provided with gaseous dopants such as POCl3 and the present invention includes the sequential diffusion of more than one dopant into the substrates. Some of the zones may be used for driving-in the dopants alternatively, for other processes, e.g. oxidation. The present invention also includes a method of operating the apparatus and the use of the apparatus in processing solar cells.