Texas Instruments Corporation

James Robert Todd

Henry Litzmann Edwards

Binghua Hu

Shanjen Pan

Sameer P Pendharkar

Louis N Hutter

Xiaoju Wu

Pinghai Hao

Michael C Smayling

Andrew Marshall

Imran Khan

Ralf Peter Brederlow

Andrew Derek Strachan

Joe R Trogolo

Eric G Soenen

Roy Clifton Jones, Iii

Tobias Bernhard Fritz

David R Cotton

William E Nehrer

Michael Szelong

Stephanie Leanne Hilbun

Tsutomu Kubota

Taylor R Efland

Seetharaman Sridhar

Alexei Sadovnikov

Jozef C Mitros

Tathagata Chatterjee

John P Erdeljac

Weidong Tian

Georges Falessi

Steven Loveless

Dhanoop Varghese

John K Lee

Manuel Torreno

Jozef D Mitros

An integrated circuit comprises a semiconductor substrate having a surface. A lateral resistor is arranged in a first plane parallel to the surface of the substrate. A vertical reference resistor comprises a layer arranged in a second plane parallel to the surface of the substrate and deeper than the first plane. This layer is doped to promote current flow in the second plane. The vertical reference resistor further comprises a first trench and a second trench coupled between the layer and the surface of the substrate. The first and second trenches are arranged in a vertical direction orthogonal to the first and the second planes and are doped to impede current flow in the vertical direction. A cross-section of the first and second trenches is two-fold rotationally symmetric around the vertical direction, and the lateral resistor and the first and second trenches have the same temperature coefficient.

Tracking temperature compensation of an x/y stress independent resistor

Described examples include integrated circuits, drain extended transistors and fabrication methods in which a silicide block material or other protection layer is formed on a field oxide structure above a drift region to protect the field oxide structure from damage during deglaze processing. Further described examples include a shallow trench isolation (STI) structure that laterally surrounds an active region of a semiconductor substrate, where the STI structure is laterally spaced from the oxide structure, and is formed under gate contacts of the transistor.

Protection of drain extended transistor field oxide

Described examples include integrated circuits, drain extended transistors and fabrication methods in which an oxide structure is formed over a drift region of a semiconductor substrate, and a shallow implantation process is performed using a first mask that exposes the oxide structure and a first portion of the semiconductor substrate to form a first drift region portion for connection to a body implant region. A second drift region portion is implanted in the semiconductor substrate under the oxide structure by a second implantation process using the first mask at a higher implant energy.

Drain extended transistor

A laterally diffused metal oxide semiconductor (LDMOS) device includes a substrate having a p-epi layer thereon, a p-body region in the p-epi layer and an ndrift (NDRIFT) region within the p-body to provide a drain extension region. A gate stack includes a gate dielectric layer over a channel region in the p-body region adjacent to and on respective sides of a junction with the NDRIFT region. A patterned gate electrode is on the gate dielectric. A DWELL region is within the p-body region. A source region is within the DWELL region, and a drain region is within the NDRIFT region. An effective channel length (Leff) for the LDMOS device is 75 nm to 150 nm which evidences a DWELL implant that utilized an edge of the gate electrode to delineate an edge of a DWELL ion implant so that the DWELL region is self-aligned to the gate electrode.

LDMOS device with body diffusion self-aligned to gate

Described examples include integrated circuits, drain extended transistors and fabrication methods therefor, including a multi-fingered transistor structure formed in an active region of a semiconductor substrate, in which a transistor drain finger is centered in a multi-finger transistor structure, a transistor body region laterally surrounds the transistor, an outer drift region laterally surrounds an active region of the semiconductor substrate, and one or more inactive or dummy structures are formed at lateral ends of the transistor finger structures.

Drain centered LDMOS transistor with integrated dummy patterns

An integrated circuit which includes a field-plated FET is formed by forming a first opening in a layer of oxide mask, exposing an area for a drift region. Dopants are implanted into the substrate under the first opening. Subsequently, dielectric sidewalls are formed along a lateral boundary of the first opening. A field relief oxide is formed by thermal oxidation in the area of the first opening exposed by the dielectric sidewalls. The implanted dopants are diffused into the substrate to form the drift region, extending laterally past the layer of field relief oxide. The dielectric sidewalls and layer of oxide mask are removed after the layer of field relief oxide is formed. A gate is formed over a body of the field-plated FET and over the adjacent drift region. A field plate is formed immediately over the field relief oxide adjacent to the gate.

Drift region implant self-aligned to field relief oxide with sidewall dielectric

In various examples, a method and apparatus are provided to achieve dynamic biasing to mitigate electrical stress. Described examples include a device includes a first resistor portion having a first terminal and a second terminal, and a second resistor portion having a third terminal and a fourth terminal. The device also includes a well in a substrate proximate to the first resistor portion and the second resistor portion and an insulating layer between the well and the first resistor portion and the second resistor portion. The device also includes a transistor having a control terminal coupled to the second terminal of the first resistor portion and the third terminal of the second resistor portion, the transistor having a first current-handling terminal coupled to a first voltage and a second current-handling terminal coupled to a current source and to the well.

Dynamic biasing to mitigate electrical stress in integrated resistors

A laterally diffused MOS (LDMOS) device includes a substrate having a p-epi layer thereon. A p-body region is in the p-epi layer. An ndrift (NDRIFT) region is within the p-body region providing a drain extension region, and a gate dielectric layer is formed over a channel region in the p-body region adjacent to and on respective sides of a junction with the NDRIFT region, and a patterned gate electrode on the gate dielectric. A DWELL region is within the p-body region, sidewall spacers are on sidewalls of the gate electrode, a source region is within the DWELL region, and a drain region is within the NDRIFT region. The p-body region includes a portion being at least one 0.5 &#x3bc;m wide that has a net p-type doping level above a doping level of the p-epi layer and a net p-type doping profile gradient of at least 5/&#x3bc;m.

LDMOS device with graded body doping

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Plano, TX, United States of America

James Robert Todd