Semiconductor device with super junction region

Abstract

A semiconductor device includes a first-conductivity-type semiconductor layer which includes a cell region portion and a junction terminating region portion. The junction terminating region portion is a region portion which is positioned in an outer periphery of the cell region portion to maintain a breakdown voltage by extending a depletion layer to attenuate an electric field.

What is claimed is: 
     
       1. A semiconductor device comprising:
 a first—first conductivity type semiconductor layer which includes a cell region portion and a junction terminating region portion, said junction terminating region portion being a region portion which is positioned in an outer periphery of the cell region portion to maintain a breakdown voltage by extending a depletion layer to attenuate an electric field; 
 a second-first conductivity type semiconductor layer which is formed on one surface of the first—first conductivity type semiconductor layer; 
 a first main electrode which is electrically connected to the second-first conductivity type semiconductor layer; 
 first-second conductivity type semiconductor layers, which are formed in the cell region portion of the first—first conductivity type semiconductor layer to extend in substantially vertical directions to said one surface of the first—first conductivity type semiconductor layer, respectively, and which are periodically disposed in a first direction, which is an arbitrary direction parallel to said one surface; 
 a second—second conductivity type semiconductor layer which is selectively formed in the other surface portion of the first—first conductivity type semiconductor layer so as to contact the first-second conductivity type semiconductor layers; 
 a third-first conductivity type semiconductor layer which is selectively formed in the surface portion of the second—second conductivity type semiconductor layer; 
 a second main electrode which is formed so as to contact the second—second conductivity type semiconductor layer and the third-first conductivity type semiconductor layer; 
 a control electrode which is formed on the surface of the first—first conductivity type semiconductor layer sandwiched by the adjacent portions of the second—second conductivity type semiconductor layers layer, the surface of the adjacent portions of the second—second conductivity type semiconductor layers layer and the surface of the third-first conductivity type semiconductor layer, with a gate insulating film interposed therebetween; and 
 third-second conductivity type semiconductor layers which are formed in the junction terminating region portion and are periodically disposed in at least one direction of the first direction and a second direction perpendicular to the first direction; 
 a fourth-second conductivity type semiconductor layer which is formed in the vicinity of a boundary with the cell region portion in said junction terminating region portion; and 
 a fifth-second conductivity type semiconductor layer which is formed in the other surface portion of the first—first conductivity type semiconductor layer, wherein 
 the fourth-second conductivity type semiconductor layer is directly connected to the second main electrode. 
 
     
     
       2. The semiconductor device according to  claim 1 , wherein the third-second conductivity type semiconductor layers are respectively formed in a direction which is substantially perpendicular to said one surface of the first—first conductivity type semiconductor layer. 
     
     
       3. The semiconductor device according to  claim 1 , wherein the third second conductivity type semiconductor layers are formed so as to have a polygonal or circular cross-sectional shape. 
     
     
       4. The semiconductor device according to  claim 1 , wherein at least one of the first-second conductivity type semiconductor layers and the third-second conductivity type semiconductor layers has a polygonal or circular plane shape. 
     
     
       5. The semiconductor device according to  claim 1 , wherein the first-second conductivity type semiconductor layers and the third-second conductivity type semiconductor layers have a stripe-shaped plane shape. 
     
     
       6. The semiconductor device according to  claim 1 , which further comprises an insulating film which is formed in at least any of the first-second conductivity type semiconductor layer, the third-second conductivity type semiconductor layer, a region portion of the first—first conductivity type semiconductor layers layer which region portion is sandwiched by the first-second conductivity type semiconductor layers, a region portion of the first—first conductivity type semiconductor layer which region portion is sandwiched by the third-second conductivity type semiconductor layers, a boundary surface between the first-second conductivity type semiconductor layers and the first—first conductivity type semiconductor layer, and a boundary surface between the third-second conductivity type semiconductor layers and the first—first conductivity type semiconductor layer. 
     
     
       7. The semiconductor device according to  claim 6 , wherein said insulating film has a stripe-shaped plane shape. 
     
     
       8. The semiconductor device according to  claim 7 , wherein said insulating films film is provided as plurality of portions that are positioned so as to be separated from one another at a predetermined intervals interval. 
     
     
       9. The semiconductor device according to  claim 1 , wherein, assuming that an impurity amount of the third-second conductivity type semiconductor layers is N 1  and that an impurity amount of the first-second conductivity type semiconductor layers is N 2 , N 1  is greater than N 2 . 
     
     
       10. The semiconductor device according to  claim 9 , wherein the ratio N 1 /N 2  of the impurity amount N 1  of the third-second conductivity type semiconductor layers and the impurity amount N 2  of the first-second conductivity type semiconductor layers satisfies the following expression:
   1<N 1 /N 2 <1.63. 
 
     
     
       11. The semiconductor device according to  claim 1 , wherein, assuming that an arrangement interval of the third-second conductivity type semiconductor layers is CP 1  and that an arrangement interval of the first-second conductivity type semiconductor layers is CP 2 , CP 1  is narrower than CP 2 . 
     
     
       12. The semiconductor device according to  claim 11 , wherein the ratio CP 2 /CP 1  of the arrangement interval CP 1  of the third-second conductivity type semiconductor layers and the arrangement interval CP 2  of the first-second conductivity type semiconductor layers satisfies the following expression:
   1<CP 2 /CP 1 <2,. 
 
     
     
       13. The semiconductor device according to  claim 1 , wherein the first—first conductivity type semiconductor layer is formed such that an impurity concentration in said junction terminating region portion is lower than an impurity concentration in the cell region portion. 
     
     
       14. The semiconductor device according to  claim 1 , which further comprises a fourth-first conductivity type semiconductor layer which is provided between the first—first conductivity type semiconductor layer and the second-first conductivity type semiconductor layer, the impurity concentration of the fourth-first conductivity type semiconductor layer being lower than that of the first—first conductivity type semiconductor layer. 
     
     
       15. The semiconductor device according to  claim 1 , which further comprises a fourth-second conductivity type semiconductor layer which is formed in the vicinity of a boundary with the cell region portion in said junction terminating region portion so as to surround the cell region portion and which is connected to the first main electrode and the second main electrode. 
     
     
       16. The semiconductor device according to  claim 1 , which further comprises a junction terminating structure including a field plate electrode which is provided on the first—first conductivity type semiconductor layer in said junction terminating region portion with an insulating film interposed therebetween. 
     
     
       17. The semiconductor device according to  claim 1 , which further comprises a junction terminating structure including a resurf layer which is formed in surface portions of the first—first conductivity type semiconductor layer and of the third-second conductivity type semiconductor layers in said junction terminating region portion. 
     
     
       18. The semiconductor device according to  claim 1 , which further comprises a junction terminating structure including a plurality of guard ring layers which are formed in surface portions of the first—first conductivity type semiconductor layer in said junction terminating region portion, or in surface portions of the first—first conductivity type semiconductor layer and of the third-second conductivity type semiconductor layers. 
     
     
       19. The semiconductor device according to claim 1, wherein the fifth-second conductivity type semiconductor layer contacts at least one third-second conductivity type semiconductor layer. 
     
     
       20. The semiconductor device according to claim 1, wherein the fifth-second conductivity type semiconductor layer is a guard ring layer. 
     
     
       21. The semiconductor device according to claim 20, wherein the fifth-second conductivity type semiconductor layer is floating potential. 
     
     
       22. The semiconductor device according to claim 1, wherein the fifth-second conductivity type semiconductor layer is floating potential. 
     
     
       23. The semiconductor device according to claim 1, wherein the fifth-second conductivity type semiconductor layer has a first portion having a first impurity amount and a second portion having a second impurity amount, the first portion being at the other surface side of the fifth-second conductivity type semiconductor layer, the second portion being at the one surface side of the fifth-second conductivity type semiconductor layer, and the first impurity amount is greater than the second impurity amount. 
     
     
       24. The semiconductor device according to claim 1, wherein the third-second conductivity type semiconductor layer contacts the second-first conductivity type semiconductor layer. 
     
     
       25. The semiconductor device according to claim 1, wherein the third-second conductivity type semiconductor layers are disposed in the second direction. 
     
     
       26. The semiconductor device of claim 1, wherein third-second conductivity type semiconductor layer extends between portions of the first-first conductivity type semiconductor layer from the junction terminating region and into the cell region portion. 
     
     
       27. The semiconductor device of claim 1, wherein the fourth-second conductivity type semiconductor layer surrounds the cell region portion. 
     
     
       28. The semiconductor device of claim 27, wherein the second-second conductivity type semiconductor layer is spaced from the fourth-second conductivity type semiconductor layer. 
     
     
       29. A semiconductor device comprising:
 a first-first conductivity type semiconductor layer which includes a cell region portion and a junction terminating region portion, said junction terminating region portion being a region portion which is positioned in an outer periphery of the cell region portion to maintain a breakdown voltage by extending a depletion layer;   a second-first conductivity type semiconductor layer which is formed on one surface of the first-first conductivity type semiconductor layer;   a first main electrode which is electrically connected to the second-first conductivity type semiconductor layer;   first-second conductivity type semiconductor layers, which are formed in the cell region portion of the first-first conductivity type semiconductor layer to extend in substantially vertical directions to said one surface of the first-first conductivity type semiconductor layer, respectively, and which are periodically disposed in a first direction, which is an arbitrary direction parallel to said one surface;   a second-second conductivity type semiconductor layer which is selectively formed in the other surface portion of the first-first conductivity type semiconductor layer so as to contact the first-second conductivity type semiconductor layers;   a third-first conductivity type semiconductor layer which is selectively formed in the surface portion of the second-second conductivity type semiconductor layer;   a second main electrode which is formed so as to contact the second-second conductivity type semiconductor layer and the third-first conductivity type semiconductor layer;   a control electrode which is formed on the surface of the first-first conductivity type semiconductor layer sandwiched by adjacent portions of the second-second conductivity type semiconductor layer, the surface of the adjacent portions of the second-second conductivity type semiconductor layer and the surface of the third-first conductivity type semiconductor layer, with a gate insulating film interposed therebetween;   third-second conductivity type semiconductor layers which are formed in the junction terminating region portion and are periodically disposed in at least one direction of the first direction and a second direction perpendicular to the first direction, at least one of the third-second conductivity type layers extending from the junction terminating region portion inwardly of the cell region portion; and   a fourth-second conductivity type semiconductor layer which is formed in the vicinity of a boundary with the cell region portion in said junction terminating region portion, and is directly connected to the second main electrode.   
     
     
       30. The semiconductor device of claim 29, wherein the portion of the at least one third-second conductivity type semiconductor layer extending from the junction terminating region portion inwardly of the cell region portion extends between either the third-first conductivity type semiconductor layer and the first main electrode or the second main electrode and the first main electrode. 
     
     
       31. The semiconductor device of claim 29, further comprising:
 a first third-second conductivity type semiconductor layer extending from the junction terminating region portion inwardly of the cell region portion and between the third-first conductivity type semiconductor layer and the first main electrode; and   a second third-second conductivity type semiconductor layer spaced from the first third-second conductivity type semiconductor layer with a portion of the first-first conductivity type semiconductor layer disposed therebetween, the second third-second conductivity type semiconductor layer extending from the junction terminating region portion inwardly of the cell region portion and between the first main electrode and the second main electrode.   
     
     
       32. A semiconductor device, comprising:
 a first semiconductor layer of a first conductivity type which includes a cell region portion and a junction terminating region portion, said junction terminating region portion being positioned in an outer periphery of the cell region portion and extending a depletion layer to the outer periphery of the cell region portion;   a second semiconductor layer of the first conductivity type which is formed on one surface of the first semiconductor layer;   a first main electrode which is electrically connected to the second semiconductor layer;   a plurality of third semiconductor layers of a second conductivity type, which are formed in the cell region portion of the first semiconductor layer to extend in substantially vertical directions to said one surface of the first semiconductor layer, respectively, and which are periodically disposed in a first direction, which is an arbitrary direction parallel to said one surface;   a fourth semiconductor layer of the second conductivity type which is selectively formed in the other surface portion of the first semiconductor layer so as to contact the third semiconductor layers;   a fifth semiconductor layer of the first conductivity type which is selectively formed in the surface portion of the fourth semiconductor layer;   a second main electrode which is formed so as to contact the fourth semiconductor layer and the fifth semiconductor layer;   a control electrode which is formed on the surface of the first semiconductor layer sandwiched by adjacent portions of the fourth semiconductor layer, the surface of the adjacent portions of the fourth semiconductor layer and the surface of the fifth semiconductor layer, with a gate insulating film interposed therebetween;   a plurality of sixth semiconductor layers of the second conductivity type, which are formed in the junction terminating region portion of the first semiconductor layer to extend in substantially vertical directions to said one surface of the first semiconductor layer, respectively, and which are periodically disposed in at least one direction of the first direction and a second direction perpendicular to the first direction; and   a seventh semiconductor layer of the second conductivity type formed in the vicinity of the boundary with the cell region portion in the junction terminating region portion, the seventh semiconductor layer being directly connected to the second main electrode, wherein   the junction terminating region portion comprises a field plate electrode which is provided on the first semiconductor layer with an insulating film interposed therebetween, and   the insulating film has a substantially uniform thickness.   
     
     
       33. A semiconductor device, comprising:
 a first semiconductor layer of a first conductivity type which includes a cell region portion and a junction terminating region portion, said junction terminating region portion being positioned in an outer periphery of the cell region portion and extending a depletion layer to the outer periphery of the cell region portion;   a second semiconductor layer of the first conductivity type which is formed on one surface of the first-first conductivity type semiconductor layer;   a first main electrode which is electrically connected to the second semiconductor layer;   a plurality of third semiconductor layers of a second conductivity type, which are formed in the cell region portion of the first semiconductor layer to extend in substantially vertical directions to said one surface of the first semiconductor layer, respectively, and which are periodically disposed in a first direction, which is an arbitrary direction parallel to said one surface;   a fourth semiconductor layer of the second conductivity type which is selectively formed in the other surface portion of the first semiconductor layer so as to contact the third semiconductor layers;   a fifth semiconductor layer of the first conductivity type which is selectively formed in the surface portion of the fourth semiconductor layer;   a second main electrode which is formed so as to contact the fourth semiconductor layer and the fifth semiconductor layer;   a control electrode which is formed on the surface of the first semiconductor layer sandwiched by adjacent portions of the fourth semiconductor layer, the surface of the adjacent portions of the fourth semiconductor layer and the surface of the fifth semiconductor layer, with a gate insulating film interposed therebetween;   a plurality of sixth semiconductor layers of the second conductivity type, which are formed in the junction terminating region portion of the first semiconductor layer to extend in substantially vertical directions to said one surface of the first semiconductor layer, respectively, and which are periodically disposed in at least one direction of the first direction and a second direction perpendicular to the first direction;   a plurality of seventh semiconductor layers of the second conductivity type, each of which is selectively formed in the other surface portion of the first semiconductor layer in the junction terminating region portion; and   an eighth semiconductor layer of the second conductivity type formed in the vicinity of a boundary with the cell region portion in the junction terminating region portion and directly connected to the second main electrode.   
     
     
       34. The semiconductor device according to claim 33, wherein the plurality of seventh semiconductor layers are connected to the sixth semiconductor layers. 
     
     
       35. The semiconductor device according to claim 33, further comprising a ninth semiconductor layer of the second conductivity type which is formed in the other surface portion of the first semiconductor layer in the outer periphery of the junction terminating region portion and spaced away from the cell region portion in a substantially vertical direction to the surface of the first semiconductor layer.