Group III-nitride-based transistor with gate dielectric including a fluoride -or chloride- based compound
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) and a barrier layer disposed on the buffer layer, the barrier layer including aluminum (Al) and nitrogen (N). The IC device may further include a gate terminal and a gate dielectric layer disposed between the gate terminal and the barrier layer and/or between the gate terminal and the buffer layer. In various embodiments, the gate dielectric layer may include a fluoride- or chloride-based compound, such as calcium fluoride (CaF 2 ).
1. An enhancement mode high electron mobility transistor (HEMT) device comprising:
a buffer layer disposed on a substrate, the buffer layer including a first nitride-based material;
a barrier layer disposed on the buffer layer, the barrier layer including a second nitride-based material and having a bandgap energy that is greater than a bandgap energy of the buffer layer;
a recess in the barrier layer that does not extend into the buffer layer;
a gate dielectric layer disposed in the recess, the gate dielectric layer formed of calcium fluoride (CaF 2 ), cadmium fluoride (CdF 2 ), or potassium chloride (KCI); and
a gate terminal disposed on the gate dielectric layer, wherein the gate dielectric layer is disposed between the gate terminal and the barrier layer or between the gate terminal and the buffer layer.
2. The enhancement mode HEMT device of claim 1 , wherein the buffer layer includes Gallium Nitride (GaN).
3. The enhancement mode HEMT device of claim 2 , wherein the barrier layer includes Aluminum Gallium Nitride (AIGaN), indium aluminum nitride (InAIN), or indium gallium aluminum nitride (InGaAIN).
4. The enhancement mode HEMT device of claim 1 , wherein the gate terminal is configured to control switching of the HEMT device.
5. The enhancement mode HEMT device of claim 1 , wherein the recess does not extend to the buffer layer.
6. The enhancement mode HEMT device of claim 1 , wherein a thickness of the gate dielectric layer is about 20 Angstroms to about 500 Angstroms.
7. The enhancement mode HEMT device of claim 1 , further comprising a source terminal and a drain terminal disposed on the barrier layer on opposite sides of the gate terminal, wherein the gate dielectric layer is separated from the source terminal and the drain terminal.
8. The enhancement mode HEMT device of claim 7 , further comprising:
a dielectric layer disposed on the barrier layer between the gate terminal and the source terminal and between the gate terminal and the drain terminal.
9. The enhancement mode HEMT device of claim 8 , wherein the gate dielectric layer is disposed between the gate terminal and the dielectric layer.
10. The enhancement mode HEMT device of claim 7 , wherein the gate terminal is configured to receive a control voltage to control switching of current in the barrier layer or buffer layer, and wherein the control voltage has an operating range up to 1.5 Volts or higher.
11. The enhancement mode HEMT device of claim 1 , wherein the gate dielectric layer has a higher bandgap energy than the bandgap energy of the barrier layer.