Silicon wafer and a silicon epitaxial wafer having a polycrystal silicon layer formed on a major surface including boron concentration of the polycrystal silicon layer being 1×10¹⁵atom/cm³or less

摘要

Provided is a silicon wafer which is stabilized in quality exerting no adverse influence on device characteristics and manufactured by restricting a boron contamination from the environment, and a manufacturing process therefor. Concretely, the silicon wafer is characterized by an attached boron amount thereon being 1×1010 atoms/cm2 or less. In order to manufacture such a wafer as contains a small amount of boron attached on the wafer surface, the wafer is treated in an atmosphere of boron concentration of 15 ng/m3 or less. Boron-less filters and boron adsorbing filters are used as filters in a clean room and the like so as to lower the boron concentration in the atmosphere.

主权项

1. A silicon wafer, comprising:
a silicon wafer body having a flat silicon wafer surface and a silicon wafer boron concentration; and a polycrystal silicon body having a flat polycrystal silicon surface in contact with and connected to the flat silicon wafer surface forming an interface therebetween, the polycrystal silicon body having a thickness commencing at the interface and extending in a thickness direction away from the flat silicon wafer surface, the polycrystal silicon body including a polycrystal silicon boron concentration layer commencing at the interface and extending in the thickness direction at approximately 1 μm, the polycrystal silicon boron concentration layer having a polycrystal silicon boron concentration in a range greater than zero and less than or equal to 1×1015 atoms/cm3, the polycrystal silicon boron concentration at approximately 1 μm away from the interface being less than the polycrystal silicon boron concentration at the interface.