Method of manufacturing semiconductor device with a gettering sink material layer
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorKenji Kusakabe
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Abstract
Silicon substrate is provided with silicon single-crystalline wafer, natural oxide film and poly-crystalline silicon film. The thickness of natural oxide film is controlled to be less than 10 .ANG.. Since the thickness of natural oxide film is made less than 10 .ANG., heavy metals travel smoothly from silicon single-crystalline wafer to poly-crystalline silicon film in the process of gettering. In other words, it is possible to enhance gettering effect.
Claims15
A method of manufacturing a semiconductor substrate from a wafer of semiconductor material, comprising the steps of:
- using a first etching solution to smooth a surface of the wafer;
- washing the wafer in water to remove said first etching solution;
- reducing the thickness of an oxide film naturally formed on the rear surface of said wafer as a result of washing;
- and
- forming a gettering sink material directly on the remaining natural oxide film.
A method of manufacturing a semiconductor substrate from a semiconductor wafer having a main surface and a rear surface, comprising the steps of:
- reducing the thickness of a natural oxide film formed on said rear surface to no more than 10 .ANG.;
- and
- forming a layer of gettering sink material directly on said natural oxide film.
Dependencies are inferred from the claim text.