Semiconductor device and method for fabricating the same

A method of fabricating a semiconductor device, the method comprising:

• forming a first electrode,
• stacking a pre second electrode, a pre first carbon layer, a pre tunneling oxide layer, a pre OTS layer, a pre second carbon layer, and a pre third electrode on the first electrode, sequentially,
• patterning the pre second electrode, the pre first carbon layer, the pre tunneling oxide layer, the pre OTS layer, the pre second carbon layer, and the pre third electrode to form a first memory cell, and
• forming a first mold layer surrounding the first memory cell,
• wherein the pre OTS layer contains a chalcogenide,
• wherein the pre tunneling oxide layer is formed with a first thickness, and
• wherein a threshold voltage of the first memory cell increases as the first thickness increases.

A method of fabricating a semiconductor device, the method comprising:

• forming a first word line extending in a first direction,
• forming a first memory cell on the first word line,
• forming a bit line on the first memory cell, extending in a second direction intersecting the first direction,
• forming a second memory cell on the bit line, and
• forming a second word line on the second memory cell, extending in the first direction,
• wherein the first memory cell comprises a first carbon layer, an OTS layer on the first carbon layer, a second carbon layer on the OTS layer, and at least one tunneling oxide layer between the first carbon layer and the second carbon layer, and
• wherein the OTS layer contains a chalcogenide.