Method of screening materials using forward conducting modes

A method for determining a figure of merit (FOM) for a material for use in a semiconductor device, the material having a unit cell and a crystal structure, the method comprising:

• selecting the canonical transport orientation for the unit cell;
• creating a first plurality of unit cells along the canonical transport orientation;
• providing a second plurality of unit cells along at least one transverse orientation for each of a plurality of nanowires, the at least one transverse orientation being perpendicular to the canonical transport orientation, the second plurality of unit cells corresponding to the cross-sectional area of each of the plurality of nanowires, each of the plurality of nanowires having the cross-sectional area different from the cross-sectional area of another of the plurality of nanowires;
• and
• determining the electronic structure for each of the plurality of nanowires using the first and second plurality of unit cells.
• determining a Fermi level for the electronic structure and the canonical transport orientation for each of the plurality of nanowires;
• determining a number of bands crossing the Fermi level for the electronic structure of each of the plurality of nanowires, the number of bands being the number of the forward conducting modes for the canonical transport orientation for the nanowire;
• linearly fitting the number of forward conducting modes versus a cross-sectional area of the nanowire for the plurality of nanowires to provide a slope of the number of forward conducting modes versus the cross-sectional area;
• determining a canonical transport orientation FOM for the material based on the slope, the canonical transport orientation FOM being a resistivity multiplied by a mean free path for the canonical transport orientation;
• repeating the steps of selecting the canonical transport orientation, providing the first plurality of unit cells, providing the second plurality of unit cells, determining the electronic structure, determining the Fermi level, determining the number of bands crossing the Fermi level, linearly fitting and determining the canonical transport orientation FOM for each of a plurality of remaining canonical transport orientations of the material;
• determining an FOM for the material using the canonical transport orientation FOM for the canonical transport orientation and the plurality of remaining canonical transport orientations.

A semiconductor device comprising:

• a substrate;
• and
• a plurality of interconnects on the substrate having a conductive portion, the conductive portion being a material selected by
• determining a figure of merit (FOM) for the material using only forward conducting modes for the unit cell, the FOM being a resistivity multiplied by a mean free path;
• and
• using the FOM to determine a suitability of the material for use in the semiconductor device.