Super-junction device and method of forming the same
AssigneeShanghai Hua Hong NEC Electronics Co., Ltd.
InventorShengan Xiao
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Abstract
A super-junction device including a unit region is disclosed. The unit region includes a heavily doped substrate; a first epitaxial layer over the heavily doped substrate; a second epitaxial layer over the first epitaxial layer; a plurality of first trenches in the second epitaxial layer; an oxide film in each of the plurality of first trenches; and a pair of first films on both sides of each of the plurality of first trenches, thereby forming a sandwich structure between every two adjacent ones of the plurality of first trenches, the sandwich structure including two first films and a second film sandwiched therebetween, the second film being formed of a portion of the second epitaxial layer between the two first films of a sandwich structure. A method of forming a super-junction device is also disclosed.
Claims17
A super-junction device comprising a unit region, the unit region comprising:
- a heavily doped substrate having a first type of conductivity;
- a first epitaxial layer having the first type of conductivity over the heavily doped substrate;
- a second epitaxial layer having a second type of conductivity over the first epitaxial layer;
- a plurality of first trenches in the second epitaxial layer;
- an oxide film in each of the plurality of first trenches;
- and
- a pair of first films having the first type of conductivity on both sides of each of the plurality of first trenches, thereby forming a sandwich structure between every two adjacent ones of the plurality of first trenches, the sandwich structure including two first films and a second film having the second type of conductivity sandwiched therebetween, the second film being formed of a portion of the second epitaxial layer between the two first films of a sandwich structure.
A method of forming a super-junction device, comprising the steps of:
- providing a heavily doped substrate having a first type of conductivity;
- forming a first epitaxial layer having the first type of conductivity over the heavily doped substrate;
- forming a second epitaxial layer having a second type of conductivity over the first epitaxial layer;
- forming a plurality of first trenches in the second epitaxial layer;
- forming an oxide film in each of the plurality of first trenches;
- and
- forming a pair of first films having the first type of conductivity on both sides of each of the plurality of first trenches, thereby forming a sandwich structure between every two adjacent ones of the plurality of first trenches, the sandwich structure including two first films and a second film having the second type of conductivity sandwiched therebetween, the second film being formed of a portion of the second epitaxial layer between the two first films of a sandwich structure.
Dependencies are inferred from the claim text.