Method for removing a top corner of a trench
Patent 5933749 Issued on August 3, 1999. Estimated Expiration Date: 
December 30, 2017. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
December 30, 2017. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesProcess for the production of electrical isolation zones in a CMOS integrated circuit Sucrose alkyl 4,6-orthoacylates Use of polymer spacers for the fabrication of shallow trench isolation regions with rounded top corners Trench isolation process Patent #: 5880004 InventorAssigneeApplicationNo. 000964 filed on 12/30/1997US Classes:438/435, Multiple insulative layers in groove257/E21.549, Of trenches having shape other than rectangular or V shape, e.g., rounded corners, oblique or rounded trench walls (EPO)438/424, Grooved and refilled with deposited dielectric material438/437, Conformal insulator formation438/978FORMING TAPERED EDGES ON SUBSTRATE OR ADJACENT LAYERSExaminersPrimary: Dang, TrungAttorney, Agent or FirmInternational ClassH01L 021/76Foreign Application Priority Data1997-10-27 TWAbstractA method for removing the top corner of the trench is disclosed. After the formation of an oxide layer and then a nitride layer over a substrate, a portion of the nitride layer, the oxide layer and the substrate are removed to form a trench. A mask is next formed on the nitride layer, wherein the opening of the mask is larger than the corresponding trench. A dry etching is performed to etch the exposed nitride layer and the substrate, using said mask. After removing the mask and the nitride layer, a liner oxide layer is then formed. The dry etching process removes the top corner to form a grading corner which consequently avoids charge accumulation and point discharging.Field of SearchGrooved and refilled with deposited dielectric materialRefilling multiple grooves of different widths or depths And deposition of polysilicon or noninsulative material into groove Multiple insulative layers in groove Conformal insulator formation FORMING TAPERED EDGES ON SUBSTRATE OR ADJACENT LAYERS | |
