Enhanced n-type silicon material for epitaxial wafer substrate and method of making same

A method for preparing n+ silicon material comprising the steps of:

• applying a dopant of phosphorus to silicon melt in an amount sufficient to produce an n+ doping concentration of at least 1018 atoms cm−3;
• applying a co-dopant of carbon to the silicon melt in an amount effective to promote oxygen precipitation in the silicon material in the presence of said n+ doping concentration;
• and
• applying a seed crystal to said melt and growing a crystal therefrom by withdrawing the seed in the Czochralski technique, wherein said co-dopant of carbon is at a concentration of at least 1016 atoms cm−3.

A method for preparing n+ silicon material comprising the steps of:

• applying a dopant of phosphorus to silicon melt in an amount sufficient to produce an n+ doping concentration of at least 1019 atoms cm−3;
• applying a co-dopant of carbon to the silicon melt;
• and
• applying a seed crystal to said melt and growing a crystal therefrom by withdrawing the seed in the Czochralski technique;
• the co-dopant of carbon being applied in an amount sufficient to produce a carbon concentration of at least 1.9×1016 atoms cm−3.

A method for preparing n+ silicon material comprising the steps of:

• applying a dopant of phosphorus to silicon melt in an amount sufficient to produce an n+ doping concentration of at least 1019 atoms cm−3;
• applying a co-dopant of carbon to the silicon melt;
• and
• applying a seed crystal to said melt and growing a crystal therefrom by withdrawing the seed in the Czochralski technique;
• the co-dopant of carbon being applied in a concentration sufficient in the presence of said n+ doping concentration to produce oxygen-precipitation-related bulk defects in the material of at least 109 defects cm−3.

A method for preparing n+ silicon material comprising the steps of:

• applying a dopant of phosphorus to silicon melt in an amount sufficient to produce an n+ doping concentration of at least 1019 atoms cm−3;
• applying a co-dopant of carbon to the silicon melt in an amount sufficient to produce a carbon concentration in the n+ silicon material of at least 1.9×106 atoms cm−3;
• and
• applying a seed crystal to said melt and growing a crystal therefrom by withdrawing the seed in the Czochralski technique;
• slicing the crystal into wafers and manufacturing substrate wafers therefrom;
• and
• forming an epitaxial layer on a major surface of the substrate wafers, thereby providing an active device layer for active device layer formation decoupled from defects in the substrate wafer,
• the epitaxial layer having an n-type dopant concentration at least 3 orders of magnitude less than the n+ doping concentration.