Group III-nitride transistor using a regrown structure
Embodiments of the present disclosure describe apparatuses, methods, and systems of an integrated circuit (IC) device. The IC device may include a buffer layer disposed on a substrate, the buffer layer including gallium (Ga) and nitrogen (N), a barrier layer disposed on the buffer layer, the barrier layer including aluminum (Al) and nitrogen (N), a regrown structure disposed in and epitaxially coupled with the barrier layer, the regrown structure including nitrogen (N) and at least one of aluminum (Al) or gallium (Ga) and being epitaxially deposited at a temperature less than or equal to 600° C., and a gate terminal disposed in the barrier layer, wherein the regrown structure is disposed between the gate terminal and the buffer layer. Other embodiments may be described and/or claimed.
1. An apparatus comprising:
a buffer layer disposed on a substrate, the buffer layer including gallium (Ga) and nitrogen (N);
a barrier layer disposed on the buffer layer, the barrier layer including aluminum (Al) and nitrogen (N);
a resistive regrown structure disposed in and epitaxially coupled with the barrier layer, the resistive regrown structure including nitrogen (N) and at least one of aluminum (Al) or gallium (Ga) and being epitaxially deposited at a temperature less than or equal to 600° C. such that material of the resistive regrown structure is substantially polycrystalline or amorphous; and
a gate terminal disposed in the barrier layer, wherein the resistive regrown structure is disposed between the gate terminal and the buffer layer to provide an insulating layer between the buffer layer and the gate terminal.
2. The apparatus of claim 1 , wherein the resistive regrown structure includes gallium nitride (GaN), aluminum nitride (AlN), indium gallium nitride (InGaN), indium aluminum nitride (InAlN), aluminum gallium nitride (AlGaN), or indium gallium aluminum nitride (InGaAlN).
3. The apparatus of claim 1 , wherein:
the barrier layer is composed of multiple layers including a first layer and a second layer;
the first layer is epitaxially coupled with the buffer layer and includes aluminum nitride (AlN);
the second layer is epitaxially coupled with the first layer and includes indium aluminum nitride (InAlN), aluminum gallium nitride (AlGaN), or indium gallium aluminum nitride (InGaAlN); and
the resistive regrown structure is in direct physical contact with the first layer and the second layer.
4. The apparatus of claim 1 , wherein the barrier layer is composed of a single layer of aluminum gallium nitride (AlGaN).
5. The apparatus of claim 1 , wherein a thickness of the barrier layer between the resistive regrown structure and the buffer layer is in a range of 10 angstroms to 50 angstroms.
6. The apparatus of claim 1 , wherein:
the resistive regrown structure has a bandgap energy that is greater than or equal to 5 electron volts (eV).
7. The apparatus of claim 6 , wherein:
the bandgap energy of the resistive regrown structure is a first bandgap energy;
the barrier layer has a second bandgap energy that is less than the first bandgap energy; and
the buffer layer has a third bandgap energy that is less than the second bandgap energy.
8. The apparatus of claim 1 , wherein the resistive regrown structure has a thickness that is less than or equal to 200 angstroms.
9. The apparatus of claim 1 , wherein:
the resistive regrown structure has a work function that inhibits formation of a two-dimensional electron gas (2DEG) at a gate region disposed between the gate terminal and the buffer layer; and
the gate terminal is configured to control switching of an Enhancement mode (E-mode) high electron mobility transistor (HEMT) device.
10. The apparatus of claim 1 , wherein the gate terminal is coupled with material of the barrier layer to form a Schottky junction or a metal-insulator-semiconductor (MIS) junction.
11. The apparatus of claim 1 , further comprising:
a source coupled with the barrier layer; and
a drain coupled with the barrier layer, wherein the source and the drain extend through the barrier layer into the buffer layer.
12. The apparatus of claim 11 , further comprising:
a dielectric material disposed on the barrier layer, the dielectric material encapsulating a portion of the gate terminal.
13. The apparatus of claim 12 , wherein:
the gate terminal is a T-shaped field-plate gate; and
the gate terminal includes nickel (Ni), platinum (Pt), iridium (Ir), molybdenum (Mo), or gold (Au).
14. The apparatus of claim 13 , further comprising:
a field-plate disposed on the dielectric material, the field-plate being electrically coupled with the source and capacitively coupled with the gate terminal through the dielectric material.
15. The apparatus of claim 1 , further comprising:
the substrate, the substrate including silicon (Si), silicon carbide (SiC), sapphire (Al 2 O 3 ), gallium nitride (GaN), or aluminum nitride (AlN).
16. The apparatus of claim 1 , wherein the resistive regrown structure is configured to increase a sheet resistivity of the barrier layer.
17. The apparatus of claim 9 , wherein the resistive regrown structure is configured to increase a sheet resistivity of the gate region.