Distributed current low-resistance diamond ohmic contacts
In some embodiments, a semiconductor structure can include: a diamond substrate having a surface conductive layer; a heavily doped region formed in the diamond substrate; and a metal contact positioned over the conductive surface layer such that a first portion of the heavily doped region is covered by the metal contact and a second portion of the heavily doped region is not covered by the metal contact.
1. A semiconductor structure comprising:
a diamond substrate having a surface conductive layer, the surface conductive layer comprising an H-terminated surface of the diamond substrate and a material that contains negative charge;
a heavily doped region formed in the diamond substrate; and
a metal contact positioned over the conductive surface layer such that a first portion of the heavily doped region is covered by the metal contact and a second portion of the heavily doped region is not covered by the metal contact.
2. The structure of claim 1 , wherein the heavily doped region comprises diamond doped with Boron in a concentration greater than 10 19 cm −3 .
3. The structure of claim 1 , wherein the heavily doped region has a width in the range of 0.1 to 10 μm and a depth in the range 0.2 to 0.4 μm.
4. The structure of claim 1 , wherein the heavily doped region has a width greater than 10 μm.
5. The structure of claim 1 , wherein the metal contact comprises at least one of Molybdenum (Mo), Tungsten (W), Titanium (Ti), or Tantalum (Ta), or other carbide forming material.
6. The structure of claim 1 , wherein the metal contact comprises a plurality of metal layers, wherein the plurality of metal layers includes an interface layer in contact with the heavily doped region and a bonding layer for contact with wire.
7. The structure of claim 6 , wherein the interface layer comprises Molybdenum (Mo) and the bonding layer comprises Gold (Au).