Semiconductor power device
A semiconductor power device includes a substrate, a buffer structure formed on the substrate, a barrier structure formed on the buffer structure, a channel layer formed on the barrier structure, and a barrier layer formed on the channel layer. The barrier structure includes a first functional layer on the buffer structure, a first back-barrier layer on the first functional layer, and an interlayer between the first back-barrier layer and the first functional layer. A material of the first back-barrier layer comprises Al x1 Ga 1-x1 N, a material of the first functional layer comprises Al x2 Ga 1-x2 N, 0<x1≤1, 0≤x2≤1, and x1≠x2. The interlayer includes a carbon doped or an iron doped material.
1. A semiconductor power device, comprising:
a substrate;
a buffer structure formed on the substrate;
a barrier structure formed on the buffer structure;
a channel layer formed on the barrier structure; and
a barrier layer formed on the channel layer;
wherein the barrier structure comprises a first functional layer on the buffer structure, a first back-barrier layer on the first functional layer, and an interlayer between the first back-barrier layer and the first functional layer;
wherein a material of the first back-barrier layer comprises Al x1 Ga 1-X1 N, a material of the first functional layer comprises Al x2 Ga 1-X2 N, a material of the interlayer comprises Al x3 Ga 1-x3 N, doped with carbon or iron, wherein 0<x1≤1, 0<x2≤1, x3≥0, and x3<x1<x2;
wherein a thickness of the interlayer is greater than a thickness of the first back-barrier layer and greater than a thickness of the first functional layer.
2. The semiconductor power device as claimed in claim 1 , wherein 0.5≤x2.
3. The semiconductor power device as claimed in claim 2 , wherein 0.5≤X1.
4. The semiconductor power device as claimed in claim 2 , wherein the thickness of the first back-barrier layer is less than or equal to 20 nm, and/or the thickness of the first functional layer is less than or equal to 20 nm.
5. The semiconductor power device as claimed in claim 4 , further comprises a second functional layer formed between the first functional layer and the buffer structure, wherein a material of the second functional layer comprises undoped Al x3 Ga 1-x3 N, wherein 0≤x3≤1; and wherein a thickness of the second functional layer is 200-1000 nm.
6. The semiconductor power device as claimed in claim 2 , wherein the first back-barrier layer and/or the first functional layer is undoped.
7. The semiconductor power device as claimed in claim 1 , wherein a two dimensional electron gas is formed near an interface of the channel layer and the barrier layer.
8. The semiconductor power device as claimed in claim 1 , wherein a thickness of the interlayer is less than or equal to 100 nm, and a material of the interlayer comprises GaN.
9. The semiconductor power device as claimed in claim 1 , further comprising a nucleation structure formed between the substrate and the buffer structure.
10. The semiconductor power device as claimed in claim 9 , wherein a material of the nucleation structure comprises AlN.
11. The semiconductor power device as claimed in claim 1 , wherein the buffer structure comprises a strain structure, and the strain structure comprises a superlattice structure of Al m Ga 1-m N and Al n Ga 1-n N, wherein 0≤m≤1, 0≤n≤1.
12. The semiconductor power device as claimed in claim 1 , wherein the buffer structure comprises a thick layer, a thickness of the thick layer is more than or equal to 2 um, and a material of the thick layer comprises a C-doped or a Fe-doped GaN.
13. The semiconductor power device as claimed in claim 1 , wherein a material of the barrier layer comprises Al k Ga 1-k N, wherein 0<k≤1, and a material of the channel layer comprises GaN.
14. The semiconductor power device as claimed in claim 1 , further comprises a first electrode formed on the barrier layer, and a second electrode formed on the barrier layer.
15. The semiconductor power device as claimed in claim 14 , further comprises a third electrode formed on the barrier layer.
16. The semiconductor power device as claimed in claim 15 , further comprising a cap layer formed between the barrier layer and the first electrode, the barrier layer and the second electrode, and/or the barrier layer and the third electrode.
17. The semiconductor power device as claimed in claim 16 , wherein a material of the cap layer comprises GaN, and a thickness of the cap layer is less than or equal to 10 nm.
18. The semiconductor power device as claimed in claim 1 , wherein 0.5<x2, and a material of the interlayer comprises GaN doped with carbon or iron.
19. The semiconductor power device as claimed in claim 18 , wherein the buffer structure comprises a thick layer and a strain structure, and the strain structure comprises a superlattice structure of Al m Ga 1-m N and Al n Ga 1-n N.