Trench gate lead-out structure and manufacturing method therefor
AssigneeCsmc Technologies Fab2 Co., Ltd.
InventorZheng Bian
Life of this patent
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Abstract
A trench gate lead-out structure comprises a substrate (10), a trench formed in the surface of the substrate (10) and a first dielectric layer (22) on the substrate (10), and also comprises a polysilicon gate (31) at the inner surface of the trench. The trench is partially filled by the polysilicon gate (31), so that a recess exists in the trench above the polysilicon gate (31). A second dielectric layer (41) is filled in the recess. The trench gate lead-out structure also comprises a metal plug (50). The metal plug (50) downwards penetrates through the first dielectric layer (22) and then is inserted between the second dielectric layer (41) and the polysilicon gate (31), and accordingly is connected to the polysilicon gate (31).
Claims10
A trench gate lead-out structure, comprising:
- a substrate;
- a trench located on a surface of the substrate;
- a first dielectric layer located on the substrate;
- a gate oxide layer located on an inner surface of the trench;
- a polysilicon gate located on the gate oxide layer, wherein the trench is partially filled with the polysilicon gate, such that a recess is formed on a surface of the polysilicon gate;
- a second dielectric layer filled in the recess;
- and
- a metal plug extending downwardly through the first dielectric layer and being inserted between the second dielectric layer and the polysilicon gate, such that the metal plug is connected to the polysilicon gate.
A method of manufacturing a trench gate lead-out structure, comprising:
- forming a trench on a surface of a substrate;
- forming a gate oxide layer on an inner surface of the trench;
- filling the inner surface of the trench with polysilicon without completely filling up the trench, forming a recess on a surface of the polysilicon in the trench;
- forming an insulating dielectric on the substrate and the trench;
- photoetching and etching the insulating dielectric to form a dielectric hole, thereby exposing the polysilicon of a side wall of the trench, and dividing the insulating dielectric into a first dielectric layer on the substrate and a second dielectric layer in the trench;
- performing a contact hole etch to partially remove the polysilicon surrounding the second dielectric layer, and forming a gap between the second dielectric layer and the polysilicon on both sides thereof;
- and
- performing a contact hole filling to fill a metal into the dielectric hole and the gap, and forming a metal plug connected to a polysilicon gate.
Dependencies are inferred from the claim text.