N-polar iii-nitride device structures with a p-type layer
AssigneeMonde Wireless Inc.
InventorBrian ROMANCZYK
Life of this patent
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Abstract
An N-polar III-N high-electron mobility transistor device can include a III-N channel layer over an N-face of a III-N backbarrier, wherein a compositional difference between the channel layer and the backbarrier causes a 2DEG channel to be induced in the III-N channel layer adjacent to the interface between the III-N channel layer and the backbarrier. The device can further include a p-type III-N layer over the III-N channel layer and a thick III-N cap layer over the p-type III-N layer. The III-N cap layer can cause an increase in the charge density of the 2DEG channel directly below the cap layer, and the p-type III-N layer can serve to prevent a parasitic 2DEG from forming in the III-N cap layer.
Claims20
A semiconductor device, comprising:
- a III-N backbarrier comprising one or more III-N layers, the one or more III-N layers of the III-N backbarrier comprising a first III-N layer;
- a III-N channel layer over an N-face of the first III-N layer;
- a 2DEG channel in the III-N channel layer adjacent to an interface between the III-N channel layer and the first III-N layer;
- a p-type III-N layer over an N-face of the III-N channel layer;
- and
- a III-N cap layer over an N-face of the p-type III-N layer;
- wherein the III-N channel layer and the III-N cap layer each have respective bandgaps that are less than the bandgap of the III-N layer with the largest bandgap;
- and
- wherein the III-N cap layer is substantially depleted of free electrons.
A semiconductor device, comprising:
- a III-N backbarrier comprising one or more III-N layers, the one or more III-N layers of the III-N backbarrier comprising a first III-N layer;
- a III-N channel layer over an N-face of the first III-N layer, wherein the III-N channel layer comprises a gate region and a plurality of access regions on opposite sides of the gate region;
- a 2DEG channel in the III-N channel layer adjacent to an interface between the III-N channel layer and the first III-N layer;
- a p-type III-N layer over an N-face of the III-N channel layer in the access regions;
- and
- a III-N cap layer over an N-face of the p-type III-N layer;
- wherein the III-N channel layer and the III-N cap layer each have respective bandgaps that are less than the bandgap of the III-N layer with the largest bandgap;
- wherein the III-N cap layer is over the access regions of the III-N channel layer but not over the gate region of the III-N channel layer;
- wherein the semiconductor device further comprises a source contact, a drain contact, and a gate contact;
- and
- the gate contact is over the gate region of the III-N channel layer.
A semiconductor device, comprising:
- a III-N backbarrier comprising one or more III-N layers, the one or more III-N layers of the III-N backbarrier comprising a first III-N layer;
- a III-N channel layer over an N-face of the first III-N layer, the III-N channel layer comprising a gate region and plurality of access regions on opposite sides of the gate region;
- a 2DEG channel in the III-N channel layer adjacent to an interface between the III-N channel layer and the first III-N layer;
- a III-N cap layer over an N-face of the III-N channel layer;
- and
- a p-type III-N layer;
- wherein:
- the III-N channel layer and the III-N cap layer each have respective bandgaps that are less than the bandgap of the III-N layer with the largest bandgap;
- the III-N cap layer is over the access regions of the III-N channel layer but not over the gate region of the III-N channel layer, forming a recess with III-N cap layer edges between the plurality of access regions and gate region;
- and
- the p-type III-N layer is positioned over the gate region and along the III-N cap layer edges adjacent to the gate region.
Dependencies are inferred from the claim text.