Abstract: Embodiments of the present invention are directed to a termination structure provided for a trench DMOS device to reduce occurrence of current leakage resulting from electric field crowding at the border of the active area and a method of manufacturing the same. In one embodiment, the termination structure for the trench DMOS device comprises a substrate of a first type conductivity and an epitaxial layer of the first type conductivity over the substrate. The epitaxial layer has a lower doping concentration than the substrate. A body region of a second type conductivity is provided within the epitaxial layer. A trench extends through the body region between an active area and an edge of the substrate. A gate oxide layer lines the trench and extends to the upper surface of the body region between the trench and the active area. A passivation layer is formed on the gate oxide layer, including sidewalls and a bottom surface of the trench.

Abstract: Embodiments of the present invention are directed to a termination structure provided for a trench DMOS device to reduce occurrence of current leakage resulting from electric field crowding at the border of the active area and a method of manufacturing the same. In one embodiment, the termination structure for the trench DMOS device comprises a substrate of a first type conductivity and an epitaxial layer of the first type conductivity over the substrate. The epitaxial layer has a lower doping concentration than the substrate. A body region of a second type conductivity is provided within the epitaxial layer. A trench extends through the body region between an active area and an edge of the substrate. A gate oxide layer lines the trench and extends to the upper surface of the body region between the trench and the active area. A passivation layer is formed on the gate oxide layer, including sidewalls and a bottom surface of the trench.

Abstract: Embodiments of the present invention are directed to a termination structure provided for a trench DMOS device to reduce occurrence of current leakage resulting from electric field crowding at the border of the active area and a method of manufacturing the same. In one embodiment, the termination structure for the trench DMOS device comprises a substrate of a first type conductivity and an epitaxial layer of the first type conductivity over the substrate. The epitaxial layer has a lower doping concentration than the substrate. A body region of a second type conductivity is provided within the epitaxial layer. A trench extends through the body region between an active area and an edge of the substrate. A gate oxide layer lines the trench and extends to the upper surface of the body region between the trench and the active area. A passivation layer is formed on the gate oxide layer, including sidewalls and a bottom surface of the trench.

Abstract: Embodiments of the present invention are directed to a termination structure provided for a trench DMOS device to reduce occurrence of current leakage resulting from electric field crowding at the border of the active area and a method of manufacturing the same. In one embodiment, the termination structure for the trench DMOS device comprises a substrate of a first type conductivity and an epitaxial layer of the first type conductivity over the substrate. The epitaxial layer has a lower doping concentration than the substrate. A body region of a second type conductivity is provided within the epitaxial layer. A trench extends through the body region between an active area and an edge of the substrate. A gate oxide layer lines the trench and extends to the upper surface of the body region between the trench and the active area. A passivation layer is formed on the gate oxide layer, including sidewalls and a bottom surface of the trench.

Abstract: A process for forming a gate oxide layer of a trench power MOSFET is provided. The process includes steps of providing a silicon substrate, forming a mask layer on the silicon substrate, removing a portion of the mask layer to expose a portion of the silicon substrate, removing the exposed portion of the silicon substrate to form the trench, removing remaining portion of the mask layer, forming a sacrificial oxide layer on the silicon substrate and on the bottom and sidewall of the trench by thermal oxidation under an operating temperature ranged from 1150 to 1300° C. and an operating time ranged from 20 to 60 minutes, removing the sacrificial oxide layer, and forming a gate oxide layer on the silicon substrate and on the bottom and sidewall of the trench.

Abstract: In the invention, a photoresist layer is first spread on a semiconductor structure, and then using a photomask with a specially designed pattern exposes the photoresist layer. Next, the photoresist layer is developed to form a patterned photoresist layer. Thereafter, using the patterned photoresist layer as a mask, a trench is formed in the semiconductor structure by selective etching. The pattern of the photomask according to the invention is formed as in the following steps. At first, a first pattern extending in a first direction and having a first side and a second side that is opposite to the first side is formed. Next, a second pattern extending in a second direction that is perpendicular to the first direction is formed in such a way that an end of the second pattern is connected with the first side of the first pattern. Thereafter, a concave edge is formed on the second side to substantially face the second pattern.

Abstract: A method for forming a self-aligned contact for a trench DMOS transistor comprises: providing a semiconductor substrate; etching a trench into the semiconductor substrate at a selected location on the surface of the semiconductor substrate; forming a first dielectric layer that covers the semiconductor substrate and walls of the trench; forming a plug in the trench, which comprises a step of depositing a semiconductor layer that covers the semiconductor substrate and fills in the trench, and a step of etching the semiconductor layer until the plug is below the trench for about 0.2 to 0.3 micron; forming a second dielectric layer on the plug; and forming a conductive layer over the second dielectric layer and the surface of the semiconductor substrate for ohmic contact regions.