Metal-to-two-dimensional material interface for transistors and method for fabricating same

A field effect transistor (FET) comprising:

• a channel material comprising a two-dimensional material (2D material);
• the channel material defining a channel comprising a first source/drain region, a gate region, and a second source/drain region;
• a first sublayer of metal overlaid directly on the channel, such that an interface between the 2D material and the first sublayer of metal does not have carbon atoms;
• wherein the first sublayer of metal is oxidized at the gate region;
• and
• wherein, at the first source/drain region and at the second source/drain region, a second sublayer of metal is directly overlaid on the first sublayer of metal, and a third sublayer of metal is directly overlaid on the second sublayer of metal;
• wherein the second sublayer comprises ruthenium (Ru), and the third sublayer of metal comprises tungsten (W).

A method comprising:

• growing a two-dimensional channel material (2D channel material) on a first substrate, the 2D channel material comprising transition metal atoms and chalcogen atoms;
• growing a metal stack on the 2D channel material, the metal stack comprising a base metal layer and at least one upper metal layer;
• wherein the base metal layer is directly overlaid on the 2D channel material, thereby forming an interface between the 2D channel material and the base metal layer that excludes a carbon interlayer;
• transferring the metal stack and 2D material from the first substrate to a second substrate;
• wherein the second substrate includes an oxide layer;
• identifying, for a plurality of field effect transistors, respective gate locations in the 2D channel material;
• and
• oxidizing the 2D channel material at the respective gate locations.