Non-uniform lateral profile of two-dimensional electron gas charge density in type III nitride HEMT devices using ion implantation through gray scale mask
A high electron mobility field effect transistor (HEMT) includes a two dimensional electron gas (2DEG) in the drift region between the gate and the drain that has a non-uniform lateral 2DEG distribution that increases in a direction in the drift region from the gate to the drain.
1. A high electron mobility field effect transistor (HEMT) comprising:
lattice damage in a drift region of a carrier supply layer between a gate and a drain; wherein the lattice damage increases linearly along the drift region from near the drain to near the gate; and
a two dimensional electron gas (2DEG) in the drift region between the gate and the drain that has a non-uniform lateral 2DEG distribution that increases in a direction in the drift region from the gate to the drain.
2. The HEMT of claim 1 :
wherein the lattice damage decreases linearly in a direction in the drift region from the gate to the drain.
3. The HEMT of claim 1 wherein a flat electric field along the drift region results from the 2DEG distribution.
4. The HEMT of claim 1 further comprising:
a substrate;
a channel carrier traveling layer on the substrate; and
a carrier supply layer on the channel carrier traveling layer.
5. The HEMT of claim 4 wherein:
the substrate comprises silicon (Si), sapphire, silicon carbide (SiC), OR bulk single crystal gallium nitride (GaN);
the channel carrier traveling layer comprises a GaN layer; and
the carrier supply layer comprises a AlGaN layer.
6. The HEMT of claim 5 further comprising:
a passivation layer over the AlGaN layer; and
wherein the gate comprises:
gate metal extending through the passivation layer and into the AlGaN layer; and
a gate dielectric layer surrounding the gate metal extending through the passivation layer and into the AlGaN layer.
7. The HEMT of claim 5 further comprising:
a passivation layer over the AlGaN layer; and
wherein the gate comprises:
gate metal extending through the passivation layer and the AlGaN layer and into the GaN layer; and
a gate dielectric layer surrounding the gate metal extending through the passivation layer and the AlGaN layer and into the GaN layer.
8. A field effect transistor (FET) comprising:
lattice damage in a drift region of a carrier supply layer between a gate and a drain;
wherein the lattice damage increases linearly along the drift region near the drain to near the gate.
9. The FET of claim 8 further comprising:
a two dimensional electron gas (2DEG) in the drift region between the gate and the drain that has a non-uniform lateral 2DEG distribution that increases in a direction in the drift region from the gate to the drain.
10. The FET of claim 9 wherein a flat electric field along the drift region results from the 2DEG distribution.
11. The FET of claim 8 further comprising:
a substrate;
a channel carrier traveling layer on the substrate; and
a carrier supply layer on the channel carrier traveling layer.
12. The FET of claim 11 wherein:
the substrate comprises silicon (Si), sapphire, silicon carbide (SiC), or bulk single crystal gallium nitride (GaN);
the channel carrier traveling layer comprises a GaN layer; and
the carrier supply layer comprises a AlGaN layer.
13. The FET of claim 12 further comprising:
a passivation layer over the AlGaN layer; and
wherein the gate comprises:
gate metal extending through the passivation layer and into the AlGaN layer; and
a gate dielectric layer surrounding the gate metal extending through the passivation layer and into the AlGaN layer.
14. The FET of claim 12 further comprising:
a passivation layer over the AlGaN layer; and
wherein the gate comprises:
gate metal extending through the passivation layer and the AlGaN layer and into the GaN layer; and
a gate dielectric layer surrounding the gate metal extending through the passivation layer and the AlGaN layer and into the GaN layer.