Superjunction semiconductor device with different effective epitaxial layer thicknesses and method of manufacturing same
AssigneeDB HiTek Co., Ltd.
InventorsWon Kook CHO, Myeong Bum PYUN
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Abstract
A superjunction semiconductor device with an epitaxial layer having different effective thicknesses and a method of manufacturing the same are disclosed. The superjunction semiconductor device includes an epitaxial layer having different thicknesses in a cell region and a ring region to decrease a breakdown voltage of the cell region relative to a breakdown voltage of the ring region so as to reveal a characteristic of the breakdown voltage of the cell region.
Claims18
A superjunction semiconductor device, comprising:
- a substrate;
- an epitaxial layer comprising a first epi-layer in a cell region, a second epi-layer in a transition region, and a third epi-layer in a ring region;
- first pillars in the cell region, second pillars in the transition region, third pillars in the ring region, alternating with portions of the epitaxial layer;
- body regions in the first epi-layer and respectively connected to the first pillars;
- a connection region in the second epi-layer, connected to the second pillars;
- a gate oxide film on the first epi-layer;
- and
- a gate electrode on the gate oxide film,
- wherein at least part of an uppermost surface of the second epi-layer is higher than an entire uppermost surface of the first epi-layer.
A superjunction semiconductor device, comprising:
- a second conductive type epitaxial layer comprising a first epi-layer in a cell region, a second epi-layer in a transition region, and a third epi-layer in a ring region;
- first conductive type pillars comprising first pillars in the cell region, second pillars in the transition region, and third pillars in the ring region, and alternating with portions of the epitaxial layer;
- first conductive type body regions in the first epi-layer, respectively connected to the first pillars;
- and
- a first conductive type connection region in the second epi-layer, connected to the second pillars,
- wherein the first epi-layer has a substantially flat uppermost surface, the second epi-layer has an inclined surface extending upward from the cell region to the ring region, and the third epi-layer has a substantially flat uppermost surface.
A method of manufacturing a superjunction semiconductor device, the method comprising:
- providing an epitaxial layer on a substrate, the epitaxial layer comprising a first epi-layer in a cell region, a second epi-layer in a transition region, and a third epi-layer in a ring region;
- forming first pillars in the cell region, second pillars in the transition region, and third pillars in the ring region alternating with portions of the epitaxial layer;
- decreasing a height of the first epi-layer;
- providing a gate oxide film on the first epi-layer;
- and
- providing a gate electrode on the gate oxide film.
A method of manufacturing a superjunction semiconductor device, the method comprising:
- providing a second conductive type epitaxial layer on a substrate, the epitaxial layer comprising a first epi-layer in a cell region, a second epi-layer in a transition region, and a third epi-layer in a ring region;
- forming first conductive type pillars alternating with portions of the epitaxial layer, the pillars comprising first pillars in the cell region, second pillars in the transition region, and third pillars in the ring region;
- decreasing a thickness of the first epi-layer by oxidizing the first epi-layer;
- and
- removing an oxide film formed by oxidizing the first epi-layer.
Dependencies are inferred from the claim text.