Globalfoundries Inc.

International Business Machines Corporation

Santosh Sharma

Yun Shi

Michael Joseph Zierak

Theodore James Letavic

Natalie Barbara Feilchenfeld

Anthony K Stamper

Max Gerald Levy

John J Ellis-Monaghan

Renata A Camillo-Castillo

Richard A Phelps

Vibhor Jain

Marwan H Khater

Brennan J Brown

Approaches for LDMOS devices are provided. A method of forming a semiconductor structure includes forming a gate dielectric including a first portion having a first uniform thickness, a second portion having a second uniform thickness different than the first uniform thickness, and a transition portion having tapered surface extending from the first portion to the second portion. The gate dielectric is formed on a planar upper surface of a substrate. The tapered surface is at an acute angle relative to the upper surface of the substrate.

Tapered gate oxide in LDMOS devices

Disclosed are methods that employ a mask with openings arranged in a pattern of elongated trenches and holes of varying widths to achieve a linearly graded conductivity level. These methods can be used to form a lateral double-diffused metal oxide semiconductor field effect transistor (LDMOSFET) with a drain drift region having an appropriate type conductivity at a level that increases essentially linearly from the body region to the drain region. Furthermore, these methods also provide for improve manufacturability in that multiple instances of this same pattern can be used during a single dopant implant process to implant a first dopant with a first type (e.g., N-type) conductivity into the drain drift regions of both first and second type LDMOSFETs (e.g., N and P-type LDMOSFETs, respectively). In this case, the drain drift region of a second type LDMOSFET can subsequently be uniformly counter-doped. Also disclosed are the resulting semiconductor structures.

Semiconductor structure with a dopant implant region having a linearly graded conductivity level and method of forming the structure

Various embodiments include structures for field effect transistors (FETs). In various embodiments, a structure for a FET includes: a deep n-type well; a shallow n-type well within the deep n-type well; and a shallow trench isolation (STI) region within the shallow n-type well, the STI region including: a first section having a first depth within the shallow n-type well as measured from an upper surface of the shallow n-type well, and a second section contacting and overlying the first section, the second section having a second depth within the shallow n-type well as measured from the upper surface of the shallow n-type well.

Dual shallow trench isolation (STI) structure for field effect transistor (FET)

Low leakage, high frequency devices and methods of manufacture are disclosed. The method of forming a device includes implanting a lateral diffusion drain implant in a substrate by a blanket implantation process. The method further includes forming a self-aligned tapered gate structure on the lateral diffusion drain implant. The method further includes forming a halo implant in the lateral diffusion drain implant, adjacent to the self-aligned tapered gate structure and at least partially under a source region of the self-aligned tapered gate structure.

Low leakage, high frequency devices

A method of forming a heterojunction bipolar transistor including a field plate. The method may include forming: a substrate having a selectively implanted collector (SIC) and a collector separated by a shallow trench isolation (STI), a field plate in the STI, the field plate extends below a top surface of the SIC, a base layer directly on the SIC, a heterojunction bipolar transistor (HBT) structure above the SIC, the HBT includes an emitter, the emitter is directly on the base layer, a fourth dielectric layer covering the HBT structure, the field plate and the collector, and an emitter contact, a field plate contact and a collector contact extending through the fourth dielectric layer, the emitter contact is in electrical connection with the emitter, the field plate contact is in electrical connection with the field plate and the collector contact is in electrical connection with the collector.

Field plate in heterojunction bipolar transistor with improved break-down voltage

High-voltage LDMOS devices with voltage linearizing field plates and methods of manufacture are disclosed. The method includes forming an array of poly islands and a control gate structure by patterning a poly layer formed over a deep well region and a body of a substrate. The method further includes forming a metal shield in contact with the control gate structure and over the array of poly islands.

High voltage laterally diffused metal oxide semiconductor

A high-voltage LDMOS device with voltage linearizing field plates and methods of manufacture are disclosed. The method includes forming a continuous gate structure over a deep well region and a body of a substrate. The method further includes forming oppositely doped, alternating segments in the continuous gate structure. The method further includes forming a contact in electrical connection with a tip of the continuous gate structure and a drain region formed in the substrate. The method further includes forming metal regions in direct electrical contact with segments of at least one species of the oppositely doped, alternating segments.

Disclosed are a field effect transistor (FET) (e.g., a lateral double-diffused metal oxide semiconductor field effect transistor (LDMOSFET)) and a method of forming the FET. In the FET, an etch stop pad is on a semiconductor substrate (e.g., a P-type silicon substrate). A semiconductor layer (e.g., a silicon layer) is also on the substrate and extends laterally over the etch stop pad. A first well region (e.g., an N-well region) extends through the semiconductor layer into the substrate such that it contains the etch stop pad. A second well region (e.g., a P-well region) is in the first well region aligned above the etch stop pad. A source region (e.g., a N-type source region) is in the second well region. A buried isolation region (e.g., a buried air-gap isolation region) is within the first well region aligned below the etch stop pad so as to limit vertical capacitor formation.

Lateral double-diffused metal oxide semiconductor field effect transistor (LDMOSFET) with a below source isolation region and a method of forming the LDMOSFET

High-voltage LDMOS devices with voltage linearizing field plates and methods of manufacture are disclosed. The method includes forming an insulator layer of varying depth over a drift region and a body of a substrate. The method further includes forming a control gate and a split gate region by patterning a layer of material on the insulator layer. The split gate region is formed on a first portion of the insulator layer and the control gate is formed on a second portion of the insulator layer, which is thinner than the first portion.

A lateral diffusion metal oxide semiconductor (LDMOS) comprises a semiconductor substrate having an STI structure in a top surface of the substrate, a drift region below the STI structure, and a source region and a drain region on opposite sides of the STI structure. A gate conductor is on the substrate over a gap between the STI structure and the source region and partially overlaps the drift region. A conformal dielectric layer is on the top surface and forms a mesa above the gate conductor. The conformal dielectric layer has a conformal etch-stop layer embedded therein. Contact studs extend through the dielectric layer and the etch-stop layer, and are connected to the source region, drain region, and gate conductor. A source electrode contacts the source contact stud, a gate electrode contacts the gate contact stud, and a drain electrode contacts the drain contact stud. A drift electrode is over the drift region.

Lateral diffusion metal oxide semiconductor (LDMOS)

A lateral diffusion metal oxide semiconductor (LDMOS) comprises a semiconductor substrate having an STI structure in a top surface of the substrate, a drift region below the STI structure, and a source region and a drain region on opposite sides of the STI structure. A gate conductor is on the substrate over a gap between the STI structure and the source region, and partially overlaps the drift region. Floating gate pieces are over the STI structure. A conformal dielectric layer is on the top surface and on the gate conductor and floating gate pieces and forms a mesa above the gate conductor and floating gate pieces. A conformal etch-stop layer is embedded within the conformal dielectric layer. A drift electrode is formed on the conformal etch-stop layer over, relative to the top surface, the drift region. The drift electrode has a variable thickness relative to the top surface.

Growing community of inventors

Essex Junction, VT, United States of America

Santosh Sharma