Patent ID: 11923422
Assignee: GLOBALWAFERS CO., LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A semiconductor device, comprising:
a substrate;
an initial layer located on the substrate, the initial layer comprising aluminum nitride; and
a superlattice stack located on the initial layer, the superlattice stack comprising a plurality of first films, a plurality of second films, and at least one doped layer, the plurality of first films and the plurality of second films being alternately stacked on the initial layer, wherein the at least one doped layer is arranged in the plurality of first films and/or the plurality of second films, and dopants of the at least one doped layer are selected from a group consisting of carbon, iron, and the combination thereof;
a buffer stack located between the superlattice stack and the initial layer, wherein the buffer stack comprises a plurality of stack units, and each of the plurality of stack units comprises a first base layer, a first doped layer, a second base layer, a second doped layer and a third base layer,
wherein the first doped layer is positioned between and in contact with the first base layer and the second base layer, and the second doped layer is positioned between and in contact with the second base layer and the third base layer,
a concentration of aluminum in the first base layer, a concentration of aluminum in the second base layer and a concentration of aluminum in the third base layer are the same in a same stack unit of the plurality of stack units, the first base layer, the second base layer and the third base layer of each of the plurality of stack units comprise aluminum gallium nitride, and the first base layer, the second base layer and the third base layer of each of the plurality of stack units do not comprise carbon or irons,
wherein the plurality of stack units comprises a first stack unit and a second stack unit located between the first stack unit and the superlattice stack, and the concentration of aluminum in the first base layer of the first stack unit is larger than the concentration of aluminum in the first base layer of the second stack unit.