Abstract: A field-effect transistor having cells (18) each having a source region (22), source body region (26), drift region (20), drain body region (28) and drain region (24) arranged longitudinally, laterally alternating with structures to achieve a reduced surface field. In embodiments, the structures can include longitudinally spaced insulated gate trenches (35) defining a gate region (31) adjacent the source or drain region (22, 24) and a longitudinally extending potential plate region (33) adjacent the drift region (20). Alternatively, a separate potential plate region (33) or a longitudinally extending semi-insulating field plate (50) may be provided adjacent the drift region (20). The transistor is suitable for bi-directional switching.

Abstract: The invention relates to a method of manufacturing a semiconductor device (1.

Abstract: Consistent with an example embodiment, a reduced surface field effect type (RESURF) semiconductor device is manufactured having a drift region over a drain region. Trenches are formed through openings in mask. A trench insulating layer is deposited on the sidewalls and base of the trenches followed by an overetching step to remove the trench insulating layer from the base of the trenches as well as the top of the sidewalls of the trenches adjacent to the first major surface leaving exposed silicon at the top of the sidewalls of the trench and the base of the trenches. Silicon is selectively grown plugging the trenches with silicon plug (18) leaving void.

Abstract: A method of manufacturing a trench-gate semiconductor device (1), the method including forming trenches (20) in a semiconductor body (10) in an active transistor cell area of the device, the trenches (20) each having a trench bottom and trench sidewalls, and providing silicon oxide gate insulation (21) in the trenches such that the gate insulation (33) at the trench bottoms is thicker than the gate insulation (21) at the trench sidewalls in order to reduce the gate-drain capacitance of the device.

Abstract: Semiconductor devices are fabricated using nanowires 16. A conductive gate 22 may be used to control conduction along the nanowires 16, in which case one of the contacts is a drain 12 and the other a source 18. The nanowires 16 may be grown in a trench or through-hole 8 in a substrate 2 or in particular in epilayer 3 on substrate 2. The gate 22 may be provided only at one end of the nanowires 16. The nanowires 16 can be of the same material along their length; alternatively different materials can be used, especially different materials adjacent to the gate 22 and between the gate 22 and the base of the trench.

Abstract: A semiconductor device is formed with a lower field plate (32) and optional lateral field plates (34) around semiconductor (20) in which devices are formed, for example power FETs or other transistor or diode types. The semiconductor device is manufactured by forming trenches with insulated sidewalls, etching cavities (26) at the base of the trenches which join up and then filling the trenches with conductor (30).

Abstract: A vertical semiconductor device, for example a trench-gate MOSFET power transistor (1), has a drift region (12) of one conductivity type containing spaced vertical columns (30) of the opposite conductivity type for charge compensation increase of the device breakdown voltage. Insulating material (31) is provided on the sidewalls only of trenches (20) in the drift region (12) and the opposite conductivity type material is epitaxially grown from the bottom of the trenches (20). The presence of the sidewall insulating material (31) reduces the possibility of defects during the epitaxial growth and hence excessive leakage currents in the device (1). The insulating material (31) also prevents epitaxial growth on the trench sidewalls and hence substantially prevents forming voids in the trenches which would lessen the accuracy of charge compensation. The epitaxial growth by this method can be well controlled and may be stopped at an upper level (21) below the top major surface (10a).

Abstract: Consistent with an example embodiment, a reduced surface field effect type (RESURF) semiconductor device is manufactured having a drift region over a drain region. Trenches are formed through openings in mask. A trench insulating layer is deposited on the sidewalls and base of the trenches followed by an overetching step to remove the trench insulating layer from the base of the trenches as well as the top of the sidewalls of the trenches adjacent to the first major surface leaving exposed silicon at the top of the sidewalls of the trench and the base of the trenches. Silicon is selectively grown plugging the trenches with silicon plug (18) leaving void.

Abstract: A vertical insulated gate transistor is manufactured by providing a trench (26) extending through a source layer (8) and a channel layer (6) towards a drain layer (2). A spacer etch is used to form gate portions (20) along the trench side walls, a dielectric material (30) is filled into the trench between the sidewalls gate portions (20), and a gate electrical connection layer (30) is formed at the top of the trench electrically connecting the gate portions (20) across the trench.

Abstract: A trench-gate semiconductor device (100) has a trench network (STR1, ITR1) surrounding a plurality of closed transistor cells (TCS). The trench network comprises segment trench regions (STR1) adjacent sides of the transistor cells (TCS) and intersection trench regions (ITR1) adjacent corners of the transistor cells. As shown in FIG. 16 which is a section view along the line II-II of FIG. 11, the intersection trench regions (ITR1) each include insulating material (21D) which extends from the bottom of the intersection trench region with a thickness which is greater than the thickness of the insulating material (21B1) at the bottom of the segment trench regions (STR1). The greater thickness of the insulating material (21D) extending from the bottom of the intersection trench regions (ITR1) is effective to increase the drain-source reverse breakdown voltage of the device (100).

Abstract: The invention relates to a trench MOSFET with drain (8), drift (10) body (12) and source (14) regions. The drift region is doped to have a high concentration gradient. A field plate electrode (34) is provided adjacent to the drift region (10) and a gate electrode (32) next to the body region (12).

Abstract: An electric device is disclosed comprising a pn-heterojunction (4) formed by a nanowire (3) of 111-V semiconductor material and a semiconductor body (1) comprising a group IV semiconductor material. The nanowire (3) is positioned in direct contact with the surface (2) of the semiconductor body (1) and has a first conductivity type, the semiconductor body (1) has a second conductivity type opposite to the first conductivity type, the nanowire (3) forming with the semiconductor body (1) a pn-heterojunction (4). The nanowire of III-V semiconductor material can be used as a diffusion source (5) of dopant atoms into the semiconductor body. The diffused group III atoms and/or the group V atoms from the III-V material are the dopant atoms forming a region (6) in the semiconductor body in direct contact with the nanowire (3).

Abstract: The invention relates to a trench MOSFET with drain (8), d? ft region (10) body (12) and source (14).

Abstract: A method of making a trench MOSFET includes forming a nitride liner 50 on the sidewalls 28 of a trench and a plug of doped polysilicon 26 at the bottom of a trench. The plug of polysilicon 26 may then be oxidised to form a thick oxide plug 30 at the bottom of the trench whilst the nitride liner 50 protects the sidewalls 28 from oxidation. This forms a thick oxide plug at the bottom of the trench thereby reducing capacitance between gate and drain.

Abstract: A RESURF trench gate MOSFET has a sufficiently small pitch (close spacing of neighbouring trenches) that intermediate areas of the drain drift region are depleted in the blocking condition of the MOSFET. However, premature breakdown can still occur in this known device structure at the perimeter/edge of the active device area and/or adjacent the gate bondpad. To counter premature breakdown, the invention adopts two principles: the gate bondpad is either connected to an underlying stripe trench network surrounded by active cells, or is directly on top of the active cells, and a compatible 2D edge termination scheme is provided around the RESURF active device area. These principles can be implemented in various cellular layouts e.g.

Abstract: A method of manufacturing a trench-gate semiconductor device (1), the method including forming trenches (20) in a semiconductor body (10) in an active transistor cell area of the device, the trenches (20) each having a trench bottom and trench sidewalls, and providing silicon oxide gate insulation (21) in the trenches such that the gate insulation (33) at the trench bottoms is thicker than the gate insulation (21) at the trench sidewalls in order to reduce the gate-drain capacitance of the device.

Abstract: A trench-gate semiconductor device (100) has a trench network (STR1), ITR1) surrounding a plurality of closed transistor cells (TCS). The trench network comprises segment trench regions (STR1) adjacent sides of the transistor cells (TCS) and intersection trench regions (ITR1) adjacent corners of the transistor cells. As shown in FIG. 16 which is a section view along the line II-II of FIG. 11, the intersection trench regions (ITR1) each include insulating material (21D) which extends from the bottom of the intersection trench region with a thickness which is greater than the thickness of the insulating material (21B1) at the bottom of the segment trench regions (STR1). The greater thickness of the insulating material (21D) extending from the bottom of the intersection trench regions (ITR1) is effective to increase the drain-source reverse breakdown voltage of the device (100).

Abstract: In semiconductor devices which include an insulated trench electrode (11) in a trench (20), for example, trench-gate field effect power transistors and trenched Schottky diodes, a cavity (23) is provided between the bottom (25) of the trench electrode (11) and the bottom (27) of the trench (20) to reduce the dielectric coupling between the trench electrode (11) and the body portion at the bottom (27) of the trench in a compact manner. In power transistors, the reduction in dielectric coupling reduces switching power losses, and in Schottky diodes, it enables the trench width to be reduced.

Abstract: A vertical insulated gate transistor is manufactured by providing a trench (26) extending through a source layer (8) and a channel layer (6) towards a drain layer (2). A spacer etch is used to form gate portions (20) along the trench side walls, a dielectric material (30) is filled into the trench between the sidewalls gate portions (20), and a gate electrical connection layer (30) is formed at the top of the trench electrically connecting the gate portions (20) across the trench.

Abstract: A method of making a trench MOSFET includes forming a layer of porous silicon (26) at the bottom of a trench and then oxidizing the layer of porous silicon (26) to form a plug (30) at the bottom of the trench. This forms a thick oxide plug at the bottom of the trench thereby reducing capacitance between gate and drain.