Semiconductor device and a method for manufacturing a semiconductor device
AssigneeNexperia B.V.
InventorsSteven Peake, Md Imran Siddiqui
Life of this patent
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Abstract
A method of creating a vertical semiconductor device, the method includes the steps of performing a LOCal Oxidation of Silicon, LOCOS, process in a vertical trench of a semiconductor material so that oxide material is formed inside the vertical trench, and ledges are formed by the oxide material, inside the vertical trench, as a result of the LOCOS process, so that a lower region of reduced lateral distance is formed between the oxide material, at a base of the trench, depositing the trench with polysilicon and etching the polysilicon downward up to the oxide material using interferometric end point detection, so that polysilicon remains in the lower region.
Claims7
A method of creating a vertical semiconductor device, the method comprising the steps of:
- etching a vertical trench in a semiconductor material;
- depositing oxide at the bottom of the trench and forming an oxide layer at sidewalls of the trench;
- depositing nitride in the vertical trench;
- performing a LOCal Oxidation of Silicon (LOCOS) process in a vertical trench of a semiconductor material so that oxide material is formed inside the vertical trench, wherein the oxide material forms ledges, inside the vertical trench, as a result of the LOCOS process, so that a lower region of reduced lateral distance is formed between the oxide material, at a base of the trench and the ledges start at the end of the nitride,
- depositing the trench with polysilicon;
- and
- etching the polysilicon downward up to the oxide material using interferometric end point detection, so that polysilicon remains in the lower region, and subsequently, etching the polysilicon further downward for a predetermined time period after the oxide material is detected by the interferometric end point detection so that an etch depth is beyond the nitride.
Dependencies are inferred from the claim text.