Abstract: A Schottky rectifier includes a semiconductor structure having first and second opposing faces each extending to define an active semiconductor region and a termination semiconductor region. The semiconductor structure includes a cathode region of the first conductivity type adjacent the first face and a drift region of the first conductivity type adjacent the second face. The drift region has a lower net doping concentration than that of the cathode region. A plurality of trenches extends from the second face into the semiconductor structure and defines a plurality of mesas within the semiconductor structure. At least one of the trenches is located in each of the active and the termination semiconductor regions. A first insulating region is located adjacent the semiconductor structure in the plurality of trenches. A second insulating region electrically isolates the active semiconductor region from the termination semiconductor region.

Abstract: In a first aspect of the invention, a modified semiconductor substrate is provided. The modified substrate comprises: (1) a semiconductor substrate; (2) at least one buffer layer provided over at least a portion of the substrate; and (3) a plurality of trenches comprising (a) a plurality of internal trenches that extend into the semiconductor substrate and (b) at least one shallow peripheral trench that extends into the at least one buffer layer but does not extend into the semiconductor substrate. In another aspect, a method of selectively providing trenches in a semiconductor substrate is provided. According to a further aspect of the invention, a trench DMOS transistor structure that includes at least one peripheral trench and a plurality of internal trenches is provided.

Abstract: A trench MOSFET includes a plurality of trench segments in an upper surface of an epitaxial layer, extending through a second conductivity type region into a first conductivity type epitaxial region, each segment at least partially separated from an adjacent segment by a terminating region, and the trench segments defining a plurality of polygonal body regions within the second conductivity type region. A first insulating layer at least partially lines each trench and a plurality of first conductive regions are provided within the trench segments adjacent to the first layer. Each of the conductive regions is connected to an adjacent conductive region by a connecting conductive region, overlying the terminating region, that bridges at least one of the terminating regions, and a plurality of first conductivity source regions are within upper portions of polygonal body regions and adjacent the trench segments, the source regions positioned outside the terminating regions.

Abstract: A trench MOSFET device and process for making the same are described. The trench MOSFET has a substrate of a first conductivity type, an epitaxial layer of the first conductivity type over the substrate, the epitaxial layer having a lower majority carrier concentration than the substrate, a plurality of trenches within the epitaxial layer, a first insulating layer, such as an oxide layer, lining the trenches, a conductive region, such as a polycrystalline silicon region, within the trenches adjacent to the first insulating layer, and one or more trench body regions and one or more termination body regions provided within an upper portion of the epitaxial layer, the termination body regions extending into the epitaxial layer to a greater depth than the trench body regions.

Abstract: A trenched field effect transistor suitable especially for low voltage power applications provides low leakage blocking capability due to a gate controlled barrier region between the source region and drain region. Forward conduction occurs through an inversion region between the source region and drain region. Blocking is achieved by a gate controlled depletion barrier. Located between the source and drain regions is a fairly lightly doped body region. The gate electrode, located in a trench, extends through the source and body regions and in some cases into the upper portion of the drain region. The dopant type of the polysilicon gate electrode is the same type as that of the body region. The body region is a relatively thin and lightly doped epitaxial layer grown upon a highly doped low resistivity substrate of opposite conductivity type. In the blocking state the epitaxial body region is depleted due to applied drain-source voltage, hence a punch-through type condition occurs vertically.

Abstract: A trench DMOS transistor cell includes a substrate of a first conductivity type and a body region located on the substrate, which has a second conductivity type. At least one trench extends through the body region and the substrate. An insulating layer lines the trench and a conductive electrode is placed in the trench overlying the insulating layer. A source region of the first conductivity type is located in the body region adjacent to the trench. The source region includes a first layer and a second layer disposed over the first layer. The first layer has a lower dopant concentration of the first conductivity type relative to the dopant concentration of the second layer.

Abstract: The preset invention discloses an improved method for fabricating a MOSFET transistor on a substrate to improve the device ruggedness. The fabrication method includes the steps of: (a) forming an epi-layer of a first conductivity type as a drain region on the substrate and then growing an gate oxide layer over the epi-layer; (b) depositing an overlaying polysilicon layer thereon and applying a polysilicon mask for etching the polysilicon layer to define a plurality of polysilicon gates; (c) removing the polysilicon mask and then carrying out a body implant of a second conductivity type followed by performing a body diffusion for forming a plurality of body regions; (d) performing a high-energy body-conductivity-type-dopant implant, eg., boron implant, to form a plurality of shallow low-concentration regions of source-conductivity-type, e.g., n-regions, under each of e gates.

Abstract: In a first aspect of the invention, a modified semiconductor substrate is provided. The modified substrate comprises: (1) a semiconductor substrate; (2) at least one buffer layer provided over at least a portion of the substrate; and (3) a plurality of trenches comprising (a) a plurality of internal trenches that extend into the semiconductor substrate and (b) at least one shallow peripheral trench that extends into the at least one buffer layer but does not extend into the semiconductor substrate. In another aspect, a method of selectively providing trenches in a semiconductor substrate is provided. According to a further aspect of the invention, a trench DMOS transistor structure that includes at least one peripheral trench and a plurality of internal trenches is provided.

Abstract: A trench Schottky barrier rectifier and a method of making the same in which the rectifier has a semiconductor region having first and second opposing faces; the semiconductor region having a drift region of first conductivity type adjacent the first face and a cathode region of the first conductivity type adjacent the second face; the drift region having a lower net doping concentration than that of the cathode region. The rectifier also has a plurality of trenches extending into the semiconductor region from the first face; the trenches defining a plurality of mesas within the semiconductor region, and the trenches forming a plurality of trench intersections.

Abstract: A trench Schottky barrier rectifier and a method of making the same are disclosed.

Abstract: A trench Schottky barrier rectifier and a method of making the same are disclosed.

Abstract: This invention discloses a semiconductor substrate supports a semiconductor power device. The semiconductor substrate includes a plurality of polysilicon segments disposed over a gate oxide layer including two outermost segments and inner segments wherein each of the inner segments functioning as a gate and the two outermost segments functioning as a field pate and an equal potential ring separated by an oxide-plug gap having an aspect ratio greater or equal to 0.5. Each of the inner segments functioning as a gate having a side wall spacer surrounding edges of the inner segments, and the oxide plug gap being filled with an oxide plug for separating the field plate from the equal potential ring. A plurality of power transistor cells disposed in the substrate for each of the gates covered by an overlying insulation layer having a plurality of contact openings defined therein.

Abstract: A Schottky rectifier is provided. The Schottky rectifier comprises: (a) a semiconductor region having first and second opposing faces, with the semiconductor region comprising a cathode region of first conductivity type adjacent the first face and a drift region of the first conductivity type adjacent the second face, and with the drift region having a lower net doping concentration than that of the cathode region; (b) one or more trenches extending from the second face into the semiconductor region and defining one or more mesas within the semiconductor region; (c) an insulating region adjacent the semiconductor region in lower portions of the trench; (d) and an anode electrode that is (i) adjacent to and forms a Schottky rectifying contact with the semiconductor at the second face, (ii) adjacent to and forms a Schottky rectifying contact with the semiconductor region within upper portions of the trench and (iii) adjacent to the insulating region within the lower portions of the trench.

Abstract: A method for making trench DMOS is provided that improves the breakdown voltage of the oxide layer in a device having at least a first trench disposed in the active region of the device and a second trench disposed in the termination region of the device. In accordance with the method, mask techniques are used to thicken the oxide layer in the vicinity of the top corner of the second trench, thereby compensating for the thinning of this region (and the accompanying reduction in breakdown voltage) that occurs due to the two-dimensional oxidation during the manufacturing process.

Abstract: A trenched field effect transistor suitable especially for low voltage power applications provides low leakage blocking capability due to a gate controlled barrier region between the source region and drain region. Forward conduction occurs through an inversion region between the source region and drain region. Blocking is achieved by a gate controlled depletion barrier. Located between the source and drain regions is a fairly lightly doped body region. The gate electrode, located in a trench, extends through the source and body regions and in some cases into the upper portion of the drain region. The dopant type of the polysilicon gate electrode is the same type as that of the body region. The body region is a relatively thin and lightly doped epitaxial layer grown upon a highly doped low resistivity substrate of opposite conductivity type. In the blocking state the epitaxial body region is depleted due to applied drain-source voltage, hence a punch-through type condition occurs vertically.

Abstract: A method of manufacturing one or more trench DMOS transistors is provided. In this method, one or more or more body regions adjacent one or more trenches are provided. The one or more trenches are lined with a first insulating layer. A portion of the first insulating layer is removed along at least the upper sidewalls of the trenches, exposing portions of the body regions. An oxide layer is then formed over at least the exposed portions of the body regions, resulting in regions of reduced majority carrier concentration within the body regions adjacent the oxide layer. This modification of the majority carrier concentration in the body regions is advantageous in that a low threshold voltage can be established within the DMOS transistor without resorting to a thinner gate oxide (which would reduce yield and switching speed) and without substantially increasing the likelihood of punch-through.

Abstract: This invention discloses a semiconductor substrate supports a semiconductor power device. The semiconductor substrate includes a plurality of polysilicon segments disposed over a gate oxide layer including two outermost segments and inner segments wherein each of the inner segments functioning as a gate and the two outermost segments functioning as a field pate and an equal potential ring separated by an oxide-plug gap having an aspect ratio greater or equal to 0.5. Each of the inner segments functioning as a gate having a side wall spacer surrounding edges of the inner segments, and the oxide plug gap being filled with an oxide plug for separating the field plate from the equal potential ring. A plurality of power transistor cells disposed in the substrate for each of the gates covered by an overlying insulation layer having a plurality of contact openings defined therein.

Abstract: In a first aspect of the invention, a modified semiconductor substrate is provided. The modified substrate comprises: (1) a semiconductor substrate; (2) at least one buffer layer provided over at least a portion of the substrate; and (3) a plurality of trenches comprising (a) a plurality of internal trenches that extend into the semiconductor substrate and (b) at least one shallow peripheral trench that extends into the at least one buffer layer but does not extend into the semiconductor substrate. In another aspect, a method of selectively providing trenches in a semiconductor substrate is provided. According to a further aspect of the invention, a trench DMOS transistor structure that includes at least one peripheral trench and a plurality of internal trenches is provided.

Abstract: A trench MOSFET device and process for making the same are described.

Abstract: This invention discloses a MOSFET power device supported on a substrate. The MOSFET power device includes a plurality metal-polysilicon gate segments disposed over a gate oxide layer and a plurality of source/drain metal segments each disposed over a corresponding drain or source region in the substrate. The MOSFET power device further includes a plurality of insulating oxide blocks each disposed between a corresponding gap between the source/drain metal segment and the metal-polysilicon gate segment Each of the metal-polysilicon gate segments includes a metal layer disposed above a polysilicon layer wherein a thickness TM of the metal layer is greater than or equal to half of the width WG of the metal-polysilicon gate, i.e., TM≧0.5(WG). And, each of the insulating oxide blocks having a thickness TO greater than or equal to half of the width of the oxide block WO, i.e., TO≧0.5(WO).