P
USRE45672EExpiredUtilityPatentIndex 56

Nitride semiconductor device

Assignee: TANIZAWA KOJIPriority: Jun 7, 1999Filed: Jun 7, 2000Granted: Sep 22, 2015
Est. expiryJun 7, 2019(expired)· nominal 20-yr term from priority
Inventors:TANIZAWA KOJI
H01S 5/305H01S 5/309Y02E10/544H01S 5/3086H01S 5/34333H01S 5/3407B82Y 20/00H10H 20/8215H10H 20/825H10H 20/812H10F 77/1248H10F 77/146H10F 71/1276H10F 10/163H10F 77/1243H01L 31/0735H01L 31/035236H01L 33/06H01L 31/03042H01L 31/03046H01L 31/1852H01L 33/32H01S 5/343
56
PatentIndex Score
1
Cited by
70
References
43
Claims

Abstract

An nitride semiconductor device for the improvement of lower operational voltage or increased emitting output, comprises an active layer comprising quantum well layer or layers and barrier layer or layers between n-type nitride. semiconductor layers and p-type nitride semiconductor layers, wherein said quantum layer in said active layer comprises InxGa1−xN (0<x<1) having a peak wavelength of 450 to 540 nm and said active layer comprises laminating layers of 9 to 13, in which at most 3 layers from the side of said n-type nitride semiconductor layers are doped with an n-type impurity selected from the group consisting of Si, Ge and Sn in a range of 5×10 16 to 2×10 18 /cm 3 .

Claims

exact text as granted — not AI-modified
What is claimed is: 
     
       1. A nitride semiconductor device which comprises an active layer containing an n-type impurity and comprising a quantum well layer or layers and a barrier layer or layers between n-type nitride semiconductor layers and p-type nitride semiconductor layers, wherein at least said quantum well layer at the proximate side in said active layer to said n-type nitride semiconductor layers is doped with an n-type impurity and wherein at least said quantum well layer at the proximate side in said active layer to said p-type nitride semiconductor layers is not doped with an n-type impurity. 
     
     
       2. A nitride semiconductor device according to  claim 1 , wherein said active layer is a MQW structure having (i) laminated layers and at least one of 1st to j-th layers counting from the side proximate to said n-type nitride semiconductor layers is doped with n-type impurity; wherein
   j′=i/6+2
   
       where i is an integer of at least 4, and wherein j is the integer portion of j′. 
     
     
       3. A nitride semiconductor device according to  claim 1 , wherein said active layer contains an n-type impurity and comprises an MQW structure comprising quantum well layers and barrier layers between n-type nitride semiconductor layers and p-type nitride semiconductor layers, wherein at least said quantum well layer at the proximate side in said active layer to said n-type nitride semiconductor layers is doped with an n-type impurity and at least said quantum well layer at the proximate side in said active layer to said n-type nitride semiconductor layers is doped with an n-type impurity, and
 wherein said barrier layer and/or said quantum well layer at the proximate side to said p-type semiconductor layers are not doped with n-type impurity.   
     
     
       4. A nitride semiconductor device according to  claim 1 , wherein said active layer contains an n-type impurity and comprises an MQW structure comprising quantum well layers and barrier layers between n-type nitride semiconductor layers and p-type nitride semiconductor layers, wherein at least said quantum well layer and said barrier layer at the proximate side in said active layer to said n-type nitride semiconductor layers are doped with n-type impurity and wherein at least said quantum well layer and said barrier layer at the proximate side in said active layer to said p-type nitride semiconductor layers are not doped with n-type impurity. 
     
     
       5. A nitride semiconductor device according to  claim 1 , wherein said active layer is a MQW structure comprising a quantum well layer and barrier layer pairs sandwiching said quantum well layer, wherein said barrier layer at the proximate side to said n-type nitride semiconductor layers are doped with n-type impurity, and said quantum well layer and said barrier layer at the proximate side to said p-type semiconductor nitride layers are not doped with n-type impurity. 
     
     
       6. A nitride semiconductor device according to  claim 1 , wherein said active layer comprises 9 to 15 layers, at most 4 layers of which, counting from the proximate side to said n-type semiconductor layers, are doped with n-type impurity. 
     
     
       7. A nitride semiconductor device according to  claim 1 , wherein said quantum well layers in said active layer comprises In x Ga 1-x N (0<x<1) which is able to emit or receive a peak wavelength belonging to a range of 470 to 530 nm. 
     
     
       8. A nitride semiconductor device according to  claim 1 , wherein said n-type impurity is selected from the group consisting of Si, Ge and Sn. 
     
     
       9. A nitride semiconductor device according to  claim 8 , wherein said n-type impurity is Si. 
     
     
       10. A nitride semiconductor device according to  claim 1 , wherein said n-type impurity content of said active layer is lower than that of said n-type nitride semiconductor layers. 
     
     
       11. A nitride semiconductor device according to  claim 1 , wherein the n-type impurity content of the active layer decreases as the distance from said n-type nitride semiconductor layers increases. 
     
     
       12. A nitride semiconductor device according to  claim 1 , wherein the n-type impurity content of said active layer is in a range of 5×10 16  to 2×10 18 /cm 3 . 
     
     
       13. A nitride semiconductor device according to  claim 12 , wherein the n-type impurity content of said barrier layer in said active layer is in a range of 5×10 16  to 2×10 18 /cm 3 . 
     
     
       14. A nitride semiconductor device according to  claim 12 , wherein the n-type impurity content of said quantum well layer in said active layer is in a range of 5×10 16  to 2×10 18 /cm 3 . 
     
     
       15. A nitride semiconductor device according to  claim 9 , wherein the n-type impurity content of said barrier layer in said active layer is in a range of 5×10 16  to 2×10 18 /cm 3 , whereas the n-type impurity content of said quantum well layer in said active layer is in a range of 5×10 16  to 2×10 18 /cm 3  and lower than that of said barrier layer. 
     
     
       16. A nitride semiconductor device according to  claim 9 , wherein the n-type impurity content of said barrier layer in said active layer is in a range of 5×10 16  2×10 18 /cm 3 , whereas the n-type impurity content of said quantum well layer in said active layer is less than 5×10 16  to 2×10 18 /cm 3  and lower than that of said barrier layer. 
     
     
       17. A nitride semiconductor device according to  claim 2 , wherein the thickness of said barrier layer or quantum well layer close or proximate to said n-type semiconductor layers is larger than that of said barrier layer or quantum well layer close or proximate to said p-type semiconductor layers. 
     
     
       18. A nitride semiconductor device according to  claim 2 , wherein the thickness of said barrier layer or quantum well layer close or proximate to said n-type semiconductor layers is smaller than that of said barrier layer or quantum well layer close or proximate to said p-type semiconductor layers. 
     
     
       19. A nitride semiconductor emitting device which comprises an active layer comprising quantum well layer or layers and barrier layer or layers between n-type nitride semiconductor layers and p-type nitride semiconductor layers, wherein said quantum layer in said active layer comprises InxGa1−xN (0<x<1) having a peak wavelength of 450 to 540 nm and said active layer comprises laminating layers of 9 to 13, in which at most 3 layers from the side of said n-type nitride semiconductor layers are doped with an n-type impurity selected from the group consisting of Si, Ge and Sn at a range of 5×10 16  to 2×10 18 /cm 3 , and the other layers are not doped with an n-type impurity. 
     
     
       20. A nitride semiconductor emitting device according to  claim 19 , wherein the thickness of said barrier layer or quantum well layer close or proximate to said n-type semiconductor layers is larger than that of said barrier layer or quantum well layer proximate to said p-type semiconductor layers. 
     
     
       21. A nitride semiconductor emitting device according to  claim 19 , wherein the thickness of said barrier layer or quantum well layer close or proximate to said n-type semiconductor layers is smaller than that of said barrier layer or quantum well layer close or proximate to said p-type semiconductor layers. 
     
     
       22. A nitride semiconductor emitting device according to  claim 19 , wherein said n-type impurity is Si. 
     
     
       23. A nitride semiconductor emitting device according to  claim 19 , wherein said quantum well layer in said active layer comprises In x Ga 1-y N (0<x<1) having a peak wavelength of 490 to 510 nm. 
     
     
       24. A nitride semiconductor emitting device according to  claim 23 , wherein said barrier layer in said active layer comprises In y Ga 1-y N (0≦y<1, y<x). 
     
     
       25. A nitride semiconductor emitting device according to  claim 19 , wherein said active layer comprises an MQW of In x Ga 1-x N (0<x<1)/In y Ga 1-y N (0≦y<1, y<x) lamination and is formed on an n-type multi-layer. 
     
     
       26. A nitride semiconductor emitting device according to  claim 25 , wherein said multi-layer is a buffer super lattice layer undoped with n-type impurity and comprising In z Ga 1-z N (0<z<1)/GaN lamination or Al w Ga 1-w N (0<w<1)/GaN lamination. 
     
     
       27. A nitride semiconductor emitting device according to  claim 26 , wherein said GaN layer of said buffer super lattice layer has a thickness of less than 70 Å and said barrier layer of said active layer has a thickness of more than 70 Å. 
     
     
       28. A nitride semiconductor emitting device according to  claim 27 , wherein said multi-layer are doped with n-impurity and comprises lamination of GaN layer and a layer selected from the group consisting of a In z Ga 1-z  (0<z<1, z<y) layer having a larger band gap energy than that of said quantum well layer and a Al w Ga w N (0<w<1) layer. 
     
     
       29. A nitride semiconductor emitting device according to  claim 28 , wherein said n-type impurity for doping into said active layer and said n-type clad layer is Si and the Si content of said active layer is in a range of 5×10 16  to 2×10 18 /cm 3 whereas the Si content of said n-clad layer is in a range of more than 5×10 17 /cm 3  and larger than that of said active layer. 
     
     
       30. A nitride semiconductor emitting device according to  claim 19 , wherein the first layer form the side of said n type nitride semiconductor layers is doped with the n type impurity and the other layers are not doped with the n type impurity. 
     
     
       31. A nitride semiconductor emitting device according to  claim 6 , wherein the first and second layers from the side of said n type nitride semiconductor layers are doped with the n type impurity. 
     
     
       32. A nitride semiconductor device which comprises an active layer comprising quantum well layers and barrier layers, n-type nitride semiconductor layers and p-type nitride semiconductor layers, said active layer being between said n-type nitride semiconductor layers and said p-type nitride semiconductor layers,
 wherein a thickness of each of said quantum well layers is not less than 10 Å and not more than 100 Å and a thickness of each of said barrier layers is 70 to 500 Å,   a total number of said quantum well layers and said barrier layers is 9 to 15, in which at most 4 layers from a side of said n-type nitride semiconductor layers are doped with an n-type impurity selected from the group consisting of Si, Ge and Sn in a range of 5×10 16  to 2×10 18 /cm 3 ,   the other layers of said quantum well layers and barrier layers are not doped with an n-type impurity and   wherein said quantum well layers comprise In x Ga 1-x N (0<x<1) and said barrier layers comprise In y Ga 1-y N (0≦y<1), wherein y<x.   
     
     
       33. The nitride semiconductor device according to claim 32, wherein an n-type semiconductor layer of said n-type semiconductor layers at a proximate side of said n-type semiconductor layers to said active layer is a superlattice layer. 
     
     
       34. The nitride semiconductor device according to claim 33, wherein said superlattice layer is undoped with n-type impurity and comprises In z Ga 1-z N (0<z<1)/GaN or Al w Ga 1-w N (0<w<1)/GaN. 
     
     
       35. The nitride semiconductor device according to claim 34, wherein GaN layer of said superlattice layer has a thickness of less than 70 Å. 
     
     
       36. The nitride semiconductor device according to claim 33, wherein said superlattice layer is doped with n-type impurity and comprises GaN layer and a layer selected from the group consisting of an In z Ga 1-z N (0<z<1) layer having a larger band gap energy than a band gap energy of said quantum well layers and an Al w Ga 1-w N (0<w<1) layer. 
     
     
       37. A nitride semiconductor device which comprises an active layer comprising quantum well layers and barrier layers, n-type nitride semiconductor layers and p-type nitride semiconductor layers, said active layer being between said n-type nitride semiconductor layers and said p-type nitride semiconductor layers,
 wherein a thickness of each of said quantum well layers is not less than 10 Å and not more than 100 Å and a thickness of each of said barrier layers is 70 to 500 Å and   a total number of said quantum well layers and said barrier layers is 9 to 15, in which at most 4 layers from a side of said n-type nitride semiconductor layers are doped with an n-type impurity selected from the group consisting of Si, Ge and Sn in a range of 5×10 16  to 2×10 18 /cm 3 , and the other layers of said quantum well layers and barrier layers are not doped with an n-type impurity and   wherein an overall thickness of said active layer is 500 to 5000 Å.   
     
     
       38. The nitride semiconductor device according to claim 37 wherein said quantum well layers comprise In x Ga 1-x N (0<x<1) and said barrier layers comprise In y Ga 1-y N (0≦y<1), wherein y<x. 
     
     
       39. The nitride semiconductor device according to claim 37, wherein an n-type semiconductor layer of said n-type semiconductor layers at a proximate side of said n-type semiconductor layers to said active layer is a superlattice layer. 
     
     
       40. The nitride semiconductor device according to claim 39, wherein said superlattice layer is undoped with n-type impurity and comprises In z Ga 1-z N (0<z<1)/GaN or Al w Ga 1-w N (0<w<1)/GaN. 
     
     
       41. The nitride semiconductor device according to claim 40, wherein said GaN layer of said superlattice layer has a thickness of less than 70 Å. 
     
     
       42. The nitride semiconductor device according to claim 39, wherein said superlattice layer is doped with n-type impurity and comprises a GaN layer and a layer selected from the group consisting of an In z Ga 1-z N (0<z<1) layer having a larger band gap energy than a band gap energy of said quantum well layers and an Al w Ga 1-w N (0<w<1) layer. 
     
     
       43. The nitride semiconductor device according to claim 37 wherein an n-type semiconductor layer contacting said active layer is undoped with an n-type impurity.

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