A method for manufacturing an electronic device includes locally implanting ionic species into a first region of a silicon nitride layer and into a first region of an electrically insulating layer located under the first region of the silicon nitride layer. A second region of the silicon nitride layer and a region of the electrically insulating layer located under the second region of the silicon nitride layer are protected from the implantation. The electrically insulating layer is disposed between a semi-conducting substrate and the silicon nitride layer. At least one trench is formed extending into the semi-conducting substrate through the silicon nitride layer and the electrically insulating layer. The trench separates the first region from the second region of the electrically insulating layer. The electrically insulating layer is selectively etched, and the etch rate of the electrically insulating layer in the first region is greater than the etch rate in the second region.

A method of manufacturing a semiconductor device having a combination structure of a horizontal oxide layer structure and a vertical oxide layer structure, can include: etching from an upper surface of the semiconductor substrate to inside of the semiconductor substrate to form a trench; depositing oxides in the trench to form the vertical oxide layer structure; etching the vertical oxide layer structure from an upper surface thereof to decrease height of the vertical oxide layer structure, and to make a top surface of the vertical oxide layer structure be below the upper surface of the semiconductor substrate, in order to expose side surfaces of the trench; and forming, by an oxidation process, the horizontal oxide layer structure to cover part of the upper surface of the semiconductor substrate and the upper surface of the vertical oxide layer structure.

The present disclosure describes a fabrication method that prevents divots during the formation of isolation regions in integrated circuit fabrication. In some embodiments, the method of forming the isolation regions includes depositing a protective layer over a semiconductor layer; patterning the protective layer to expose areas of the semiconductor layer; depositing an oxide on the exposed areas the semiconductor layer and between portions of the patterned protective layer; etching a portion of the patterned protective layer to expose the semiconductor layer; etching the exposed semiconductor layer to form isolation openings in the semiconductor layer; and filling the isolation openings with a dielectric to form the isolation regions.

A method of forming a semiconductor structure and the semiconductor structure are provided. The method includes the following operations. A semiconductor substrate is provided, in which a plurality of isolation grooves distributed at intervals are provided in the semiconductor substrate, and each of the isolation grooves includes a top region isolation groove and a bottom region isolation groove. A first protective layer covering the side wall of the top region isolation groove and the top of the semiconductor substrate is formed. Oxidation treatment is performed on the bottom region isolation groove to oxidize a part of the semiconductor substrate close to the bottom region isolation groove to form a second substrate isolation layer. A dielectric layer filling the isolation groove is formed. The first protective layer and the dielectric layer higher than the top of the semiconductor substrate are etched to form an isolation structure.

A method for manufacturing a semiconductor device includes providing a substrate structure including a substrate having multiple structures. Each of the structures includes an active region isolated by trenches in the substrate, an insulating layer on the active region, and a hardmask layer on the insulating layer. The method also includes performing a first ion implantation into a first structure configured to form a first type device, performing a pull-back process on the hardmask layer and on the insulating layer of the first structure to form a receded hardmask layer and a receded insulating layer and expose a corner portion of the active region, and performing a rounding process on the exposed corner portion. The rounded corner portion of the active region has an increased curvature radius that reduces the concentration of the electric field and improves the reliability of the semiconductor device.

A method for making a high-voltage thick gate oxide, which includes depositing a pad silicon oxide on a silicon substrate and depositing a pad silicon nitride on the pad silicon oxide; performing shallow trench isolation photolithography, etching, silicon oxide filling and chemical mechanical polishing; sequentially depositing a mask silicon nitride and a mask silicon oxide on a silicon wafer; removing the mask silicon oxide and the mask silicon nitride in a high-voltage thick gate oxide region, and remaining the pad silicon nitride between two shallow trench isolations in the high-voltage thick gate oxide region; performing first thermal oxidation growth; removing the pad silicon nitride between the two shallow trench isolations in the high-voltage thick gate oxide region; performing second thermal oxidation growth to produce a high-voltage thick gate oxide.

A method for manufacturing a trench isolation structure comprising forming a shallow trench having a wider upper section and a narrower lower section in a wafer surface, removing part of the silicon oxide by etching, forming a silicon oxide corner structure at a corner at a top corner of the shallow trench by thermal oxidation, depositing silicon nitride on the wafer surface to cover surfaces of the shallow trench silicon oxide and the silicon oxide corner structure, dry etching the silicon nitride on the shallow trench silicon oxide surface thereby forming masking silicon nitride residues extending into the trench, etching downwards to form a deep trench, forming silicon oxide layers on a side wall and the bottom of the deep trench, depositing polycrystalline silicon in the shallow and deep trenches, removing the silicon nitride, and forming silicon oxide in the shallow trench to cover the polycrystalline silicon.

A method of making a semiconductor device can include: etching a substrate to form a trench in the substrate; forming a liner oxide layer on side surfaces and a process bottom portion of the trench through an oxide layer formation method; and where an oxidation time of a junction between an upper surface of the semiconductor substrate and side walls of the trench is increased by the oxide layer formation process, in order to smoothen the junction.

A semiconductor device has a semiconductor material in a substrate. The semiconductor device has an MOS transistor. A trench in the substrate extends from a top surface of the substrate) into the semiconductor material. A shield is disposed in the trench. The shield has a contact portion which extends toward a top surface of the trench. A gate of the MOS transistor is disposed in the trench over the shield. The gate is electrically isolated from the shield. The gate is electrically isolated from the contact portion of the shield by a shield isolation layer which covers an angled surface of the contact portion extending toward the top of the trench. Methods of forming the semiconductor device are disclosed.

The present application discloses a method for fabricating the semiconductor device. The method for fabricating the semiconductor device includes forming a first dielectric layer on a substrate; forming a feature opening to exposing the substrate; performing a pre-cleaning treatment including a pre-cleaning solution to the feature opening; performing a cleaning process to the feature opening; and forming a conductive feature in the feature opening. The pre-cleaning solution includes a chelating agent and a corrosion inhibitor.