Semiconductor device

A semiconductor device comprising:

• a lower sheet structure having first-type conductivity and including a plurality of first lower semiconductor layers and a plurality of second lower semiconductor layers alternately stacked;
• an upper sheet structure having second-type conductivity and including a plurality of first upper semiconductor layers and a plurality of second upper semiconductor layers alternately stacked on the lower sheet structure;
• a lower semiconductor pattern on at least one side of the lower sheet structure;
• and
• a PN junction structure between the plurality of first lower semiconductor layers and the plurality of first upper semiconductor layers, the PN junction structure including a P-type and an N-type semiconductor material, and a same material as at least one of the plurality of second lower semiconductor layers and the plurality of second upper semiconductor layers,
• wherein the PN junction structure includes
• a first doped layer having the first-type conductivity on the lower sheet structure, and
• a second doped layer having the second-type conductivity between the first doped layer and the upper sheet structure.

A semiconductor device comprising:

• a base insulating layer;
• a lower sheet structure including a plurality of first lower semiconductor layers and a plurality of second lower semiconductor layers alternately stacked on the base insulating layer;
• an upper sheet structure including a plurality of first upper semiconductor layers and a plurality of second upper semiconductor layers alternately stacked on the lower sheet structure;
• a lower semiconductor pattern having first-type conductivity on at least one side of the lower sheet structure;
• an upper semiconductor pattern having second-type conductivity on at least one side of the upper sheet structure;
• a barrier structure between the lower semiconductor pattern and the upper semiconductor pattern;
• and
• a PN junction structure between the lower sheet structure and the upper sheet structure and overlapping the barrier structure, the PN junction structure including a P-type and an N-type semiconductor material,
• wherein the PN junction structure includes
• a first doped layer having the first-type conductivity on the lower sheet structure, and
• a second doped layer having the second-type conductivity on the first doped layer, and
• a doping concentration of first-type conductivity impurities in the first doped layer is less than or equal to a doping concentration of the first-type conductivity impurities in the lower semiconductor pattern.