Alpha Omega Semiconductor Inc.

Jongoh Kim

Hamza Yilmaz

Hong Chang

Madhur Bobde

Yeeheng Lee

John Chen

Daniel S Calafut

Anup Bhalla

Sik Lui

Daniel Ng

Yi Qiang Su

Lingpeng Guan

Yongping Ding

Ji Pan

Jun Hu

Lei Zhang

Gary Chen

Wenjun Li

Limin Weng

Xiaobin Wang

Madhur Bodbe

Yangping Ding

A semiconductor power device formed in a semiconductor substrate that includes a plurality of trenches formed at a top portion of the semiconductor substrate. The trenches extend laterally across the semiconductor substrate along a longitudinal direction and each trench has a nonlinear portion thus the nonlinear portion has a trench sidewall perpendicular to the longitudinal direction of the trench. A plurality of trench bottom dopant regions are formed below the trench bottom surface. A sidewall dopant region is formed along the perpendicular sidewall wherein the sidewall dopant region extends vertically downward along the perpendicular sidewall of the trench to reach the trench bottom dopant region and pick-up the trench bottom dopant region to the top surface of the semiconductor substrate.

Process method and structure for high voltage MOSFETs

A high density trench-gated MOSFET array and method are disclosed. It comprises semiconductor substrate partitioned into MOSFET array area and gate pickup area; epitaxial region, body region and source region; numerous precisely spaced active nitride-capped trench gate stacks (ANCTGS) embedded till the epitaxial region. Each ANCTGS comprises a stack of polysilicon trench gate with gate oxide shell and silicon nitride cap covering top of polysilicon trench gate and laterally registered to gate oxide shell. The ANCTGS forms, together with the source, body, epitaxial region, a MOSFET device in the MOSFET array area. Over MOSFET array area and gate pickup area, a patterned dielectric region atop the MOSFET array and a patterned metal layer atop the patterned dielectric region. Thus, the patterned metal layer forms, with the MOSFET array and the gate pickup area, self-aligned source and body contacts through the inter-ANCTGS separations.

High density MOSFET array with self-aligned contacts delimited by nitride-capped trench gate stacks and method

A semiconductor power device may include a lightly doped layer formed on a heavily doped layer. One or more devices are formed in the lightly doped layer. Each device includes a body region, a source region, and one or more gate electrodes formed in corresponding trenches in the lightly doped region. Each trench has a first dimension (depth), a a second dimension (width) and a third dimension (length). The body region is of opposite conductivity type to the lightly and heavily doped layers. An opening is formed between first and second trenches through an upper portion of the source region and a body contact region to the body region. A deep implant region of the second conductivity type is formed in the lightly doped layer below the body region. The deep implant region is vertically aligned to the opening and spaced away from a bottom of the opening.

Nano MOSFET with trench bottom oxide shielded and third dimensional P-body contact

This invention discloses a semiconductor power device disposed in a semiconductor substrate. The semiconductor power device comprises a plurality of trenches each having a trench endpoint with an endpoint sidewall perpendicular to a longitudinal direction of the trench and extends vertically downward from a top surface to a trench bottom surface. The semiconductor power device further includes a trench bottom dopant region disposed below the trench bottom surface and a sidewall dopant region disposed along the endpoint sidewall wherein the sidewall dopant region extends vertically downward along the endpoint sidewall of the trench to reach the trench bottom dopant region and pick-up the trench bottom dopant region to the top surface of the semiconductor substrate.

A plurality of gate trenches is formed into an epitaxial region of a first conductivity type over a semiconductor substrate. One or more contact trenches are formed into the epitaxial region, each between two adjacent gate trenches. One or more source regions of the first conductivity type are formed in a top portion of the epitaxial region between a contact trench and a gate trench. A barrier metal is formed inside each contact trench. Each gate trench is substantially filled with a conductive material separated from trench walls by a layer of dielectric material to form a gate . A heavily doped well region of a conductivity opposite the first type is provided in the epitaxial region proximate a bottom portion of each of the contact trenches. A horizontal width of a gap between the well region and the gate trench is about 0.05 &#x3bc;m to 0.2 &#x3bc;m.

Integrating enhancement mode depleted accumulation/inversion channel devices with MOSFETs

A semiconductor device includes a semiconductor substrate and epitaxial layer of a first conductivity type with the epitaxial layer on a top surface of the substrate. A body region of a second conductivity type opposite the first conductivity type is disposed near a top surface of the epitaxial layer. A first conductivity type source region is inside the body region and a drain is at a bottom surface of the substrate. An inslated gate overlaps the source and body regions. First and second trenches in the epitaxial layer are lined with insulation material and filled with electrically conductive material. Second conductivity type buried regions are positioned below the trenches. Second conductivity type charge linking paths along one or more walls of the first trench electrically connect a first buried region to the body region. A second buried region is separated from the body region by portions of the expitaxial layer.

High voltage field balance metal oxide field effect transistor (FBM)

Embodiments of the present disclosure provide a contact structure in a split-gate trench transistor device for electrically connecting the top electrode to the bottom electrode inside the trench. The transistor device comprises a semiconductor substrate and one or more trenches formed in the semiconductor substrate. The trenches are lined with insulating materials along the sidewalls inside the trenches. Each trench has a bottom electrode in lower portions of the trench and a top electrode in its upper portions. The bottom electrode and the top electrode are separated by an insulating material. A contact structure filled with conductive materials is formed in each trench in an area outside of an active region of the device to connect the top electrode and the bottom electrode. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Split poly connection via through-poly-contact (TPC) in split-gate based power MOSFETs

A semiconductor power device disposed on a semiconductor substrate comprises a plurality of trenches formed at a top portion of the semiconductor substrate extending laterally across the semiconductor substrate along a longitudinal direction each having a nonlinear portion comprising a sidewall perpendicular to a longitudinal direction of the trench and extends vertically downward from a top surface to a trench bottom surface. The semiconductor power device further includes a trench bottom dopant region disposed below the trench bottom surface and a sidewall dopant region disposed along the perpendicular sidewall wherein the sidewall dopant region extends vertically downward along the perpendicular sidewall of the trench to reach the trench bottom dopant region and pick-up the trench bottom dopant region to the top surface of the semiconductor substrate.

Process method and structure for high voltage MOSFETS

A semiconductor power device may include a lightly doped layer formed on a heavily doped layer. One or more devices are formed in the lightly doped layer. Each device may include a body region, a source region, and one or more gate electrodes formed in corresponding trenches in the lightly doped region. Each of the trenches has a depth in a first dimension, a width in a second dimension and a length in a third dimension. The body region is of opposite conductivity type to the lightly and heavily doped layers. The source region is formed proximate the upper surface. One or more deep contacts are formed at one or more locations along the third dimension proximate one or more of the trenches. The contacts extend in the first direction from the upper surface into the lightly doped layer and are in electrical contact with the source region.

Semiconductor power devices can be formed on substrate structure having a lightly doped semiconductor substrate of a first conductivity type or a second conductivity type opposite to the first conductivity type. A semiconductive first buffer layer of the first conductivity type formed above the substrate. A doping concentration of the first buffer layer is greater than a doping concentration of the substrate. A second buffer layer of the second conductivity type formed above the first buffer layer. An epitaxial layer of the second conductivity type formed above the second buffer layer. One or more heavily doped regions of the second conductivity type are formed through portions of the first buffer layer from the second buffer layer and into corresponding portions of the substrate. This abstract is provided with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Injection control in semiconductor power devices

Aspects of the present disclosure describe a high density trench-based power. The active devices may have a two-step gate oxide. A lower portion may have a thickness that is larger than the thickness of an upper portion of the gate oxide. A lightly doped sub-body layer may be formed below a body region between two or more adjacent active device structures of the plurality. The sub-body layer extends from a depth of the upper portion of the gate oxide to a depth of the lower portion of the gate oxide It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Device structure and methods of making high density MOSFETs for load switch and DC-DC applications

A plurality of gate trenches is formed into an epitaxial region of a first conductivity type over a semiconductor substrate. One or more contact trenches are formed into the epitaxial region, each between two adjacent gate trenches. One or more source regions of the first conductivity type are formed in a top portion of the epitaxial region between a contact trench and a gate trench. A barrier metal is formed inside each contact trench. Each gate trench is substantially filled with a conductive material separated from trench walls by a layer of dielectric material to form a gate. A heavily doped well region of a conductivity opposite the first type is provided in the epitaxial region proximate a bottom portion of each of the contact trenches. A horizontal width of a gap between the well region and the gate trench is about 0.05 &#x3bc;m to 0.2 &#x3bc;m.

Aspects of the present disclosure describe a high density trench-based power MOSFET with self-aligned source contacts. The source contacts are self-aligned with a first insulative spacer and a second insulative spacer, wherein the first spacer is resistant to an etching process that will selectively remove the material the second spacer is made from. It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Growing community of inventors

Portland, OR, United States of America

Jongoh Kim