Method for making electrical contact with a rear side of a semiconductor substrate during its processing

A method for electrically contacting a rear side of a semiconductor substrate when processing the semiconductor substrate, the method comprising:

• providing a substrate holder having a vacuum line for producing a vacuum;
• providing a semiconductor substrate having a substrate rear side and a substrate front side disposed opposite from the substrate rear side, the semiconductor substrate being doped with charge carrier having a first polarity;
• providing an electrically conductive contact layer formed of a semiconductor material doped with charge carriers having the first polarity;
• forming a first trench in the electrically conductive contact layer starting from a first surface of the electrically conductive contact layer;
• forming a second trench in the electrically conductive contact layer starting from a second surface of the electrically conductive contact layer;
• forming a hole in the electrically conductive contact layer extending from the first surface of the electrically conductive contact layer to the second surface of the electrically conductive contact layer;
• placing the semiconductor substrate with the substrate rear side on the substrate holder with the electrically conductive contact layer being disposed between the semiconductor substrate and the substrate holder for electrically contacting the substrate rear side when processing the semiconductor substrate, the first side of the electrically conductive contact layer facing the semiconductor substrate and the second side of the electrically conductive contact layer facing the substrate holder;
• and
• applying a vacuum to the vacuum line, feeding the vacuum through the hole from the second surface of the electrically conductive contact layer to the first surface of the electrically conductive contact layer, and distributing the
• vacuum uniformly over the rear side of the semiconductor substrate.

A method for electrically contacting a rear side of a semiconductor substrate when processing the semiconductor substrate, the method comprising:

• providing a substrate holder having a vacuum line for producing a vacuum;
• providing a semiconductor substrate having a substrate rear side and a substrate front side disposed opposite from the substrate rear side, the semiconductor substrate being doped with charge carriers having a first polarity;
• providing an electrically conductive contact layer formed of a semiconductor material doped with charge carriers having the first polarity;
• forming a first mesa in the electrically conductive contact layer starting from a first surface of the electrically conductive contact layer;
• forming a second mesa in the electrically conductive contact layer starting from a second surface of the electrically conductive contact layer;
• forming a hole in the electrically conductive contact layer extending from the first surface of the electrically conductive contact layer to the second surface of the electrically conductive contact layer;
• removing an insulating layer disposed on the substrate rear side;
• and
• placing the semiconductor substrate with the substrate rear side on the substrate holder with the electrically conductive contact layer being disposed between the semiconductor substrate and the substrate holder, the first side of the electrically conductive contact layer facing the semiconductor substrate and the second side of the electrically conductive contact layer facing the substrate holder;
• and
• applying a vacuum to the vacuum line, feeding the vacuum through the hole from the second surface of the electrically conductive contact layer to the first surface of the electrically conductive contact layer, and distributing the vacuum uniformly over the rear side of the semiconductor substrate.