Selective gate oxide formation on 2D material based transistor devices

A transistor structure, comprising:

• a semiconductor layer comprising a 2D material;
• a gate dielectric structure on the semiconductor layer, the gate dielectric structure comprising a first metal, nitrogen, and oxygen;
• a first source or drain structure in contact with the gate dielectric structure and on the semiconductor layer, the first source or drain structure comprising the first metal and nitrogen;
• a second source or drain structure on the first source or drain structure, the second source or drain structure comprising a body comprising a second metal and a layer on a sidewall of the body adjacent the gate dielectric structure, the layer comprising the second metal and oxygen;
• and
• a gate electrode, wherein the gate dielectric structure is between the gate electrode and the semiconductor layer.

A method, comprising:

• forming a first layer on a semiconductor layer, the semiconductor layer comprising a 2D material and the first layer comprising a first metal;
• forming a second layer over the first layer, the second layer comprising a second metal;
• forming a patterned layer over the second layer;
• removing a portion of the second layer within an opening of the patterned layer to expose a portion of the first layer;
• oxidizing the exposed portion of the first layer to form a gate dielectric structure comprising the first metal and oxygen;
• and
• removing the patterned layer.