International Business Machines Corporation

Francois Pagette

Marwan H Khater

Anna Wanda Topol

Gregory Gower Freeman

Christian Lavoie

Andreas Daniel Stricker

David C Ahlgren

Christopher M Schnabel

Guy M Cohen

Qizhi Liu

Alvin Jose Joseph

David Louis Harame

James Stuart Dunn

Kathryn Turner Schonenberg

Stephen Arthur St Onge

Jack Oon Chu

David William Abraham

Richard Paul Volant

Nicholas C M Fuller

Steven Erik Steen

Kunal Vaed

Jae-Sung Rieh

Embodiments of the present invention provide a bipolar transistor with low resistance base contact and method of manufacturing the same. The bipolar transistor includes an emitter, a collector, and an intrinsic base between the emitter and the collector. The intrinsic base extends laterally to an extrinsic base. The extrinsic base further includes a first semiconductor material with a first bandgap and a second semiconductor material with a second bandgap that is smaller than the first bandgap.

Bipolar transistor with low resistance base contact and method of making the same

A method for forming a metal-semiconductor alloy layer uses particular thermal annealing conditions to provide a stress free metal-semiconductor alloy layer through interdiffusion of a buried semiconductor material layer and a metal-semiconductor alloy forming metal layer that contacts the buried semiconductor material layer within an aperture through a capping layer beneath which is buried the semiconductor material layer. A resulting semiconductor structure includes the metal-semiconductor alloy layer that further includes an interconnect portion beneath the capping layer and a contiguous via portion that penetrates at least partially through the capping layer. Such a metal-semiconductor alloy layer may be located interposed between a substrate and a semiconductor device having an active doped region.

Buried metal-semiconductor alloy layers and structures and methods for fabrication thereof

In one embodiment, the invention is a method and apparatus for fabricating a heterojunction bipolar transistor. One embodiment of a heterojunction bipolar transistor includes a collector layer, a base region formed over the collector layer, a self-aligned emitter formed on top of the base region and collector layer, a poly-germanium extrinsic base surrounding the emitter, and a metal germanide layer formed over the extrinsic base.

Method and apparatus for fabricating a heterojunction bipolar transistor

Bipolar transistor with low resistance base contact

Embodiments of the invention provide a method of fabricating a semiconductor device. The method includes defining a sub-collector region in a layer of doped semiconductor material; forming an active region, a dielectric region, and a reach-through region on top of the layer of doped semiconductor material with the dielectric region separating the active region from the reach-through region; and siliciding the reach-through region and a portion of the sub-collector region to form a partially silicided conductive pathway. A semiconductor device made thereby is also provided.

Bipolar transistor with silicided sub-collector

A method of implementing sub-lithographic patterning of a semiconductor device includes forming a first set of patterned features with a single lithography step, the initial set of patterned features characterized by a linewidth and spacing therebetween; forming a first set of sidewall spacers on the first set of patterned features, and thereafter removing the first set of patterned features so as to define a second set of patterned features based on the geometry of the first set of sidewall spacers; and performing one or more additional iterations of forming subsequent sets of sidewall spacers on subsequent sets of patterned features, followed by removal of the subsequent sets of patterned features, wherein a given set of patterned features is based on the geometry of an associated set of sidewall spacers formed prior thereto, and wherein a final of the subsequent sets of patterned features is characterized by a sub-lithographic dimension.

Sublithographic patterning method incorporating a self-aligned single mask process

A heterojunction bipolar transistor structure with self-aligned sub-lithographic extrinsic base region including a self-aligned metal-semiconductor alloy and self-aligned metal contacts made to the base is disclosed. The lateral dimension of the extrinsic base region is defined by the footprint of a sacrificial spacer, and its thickness is controlled by selective epitaxy. A self-aligned semiconductor-metal alloy and self-aligned metal contacts are made to the extrinsic base using a method compatible with conventional silicon processing.

Heterojunction bipolar transistor (HBT) with self-aligned sub-lithographic metal-semiconductor alloy base contacts

Disclosed is a method of forming a transistor in an integrated circuit structure that begins by forming a collector in a substrate and an intrinsic base above the collector. Then, the invention patterns an emitter pedestal for the lower portion of the emitter on the substrate above the intrinsic base. Before actually forming the emitter or associates spacer, the invention forms an extrinsic base in regions of the substrate not protected by the emitter pedestal. After this, the invention removes the emitter pedestal and eventually forms the emitter where the emitter pedestal was positioned.

Bipolar transistor with self-aligned retrograde extrinsic base implant profile and self-aligned silicide

Embodiments of the invention provide a semiconductor device including a collector in an active region; a first and a second sub-collector, the first sub-collector being a heavily doped semiconductor material adjacent to the collector and the second sub-collector being a silicided sub-collector next to the first sub-collector; and a silicided reach-through in contact with the second sub-collector, wherein the first and second sub-collectors and the silicided reach-through provide a continuous conductive pathway for electrical charges collected by the collector from the active region. Embodiments of the invention also provide methods of fabricating the same.

The present invention relates to a device structure that comprises a substrate with front and back surfaces, and at least one semiconductor device with a first conductive structure located in the substrate and a second conductive structure located thereover. A first conductive contact is located over the front surface of the substrate and laterally offset from the first conductive structure. The first conductive contact is electrically connected to the first conductive structure by a conductive path that extends: (1) from the first conductive structure through the substrate to the back surface, (2) across the back surface, and (3) from the back surface through the substrate to the first conductive contact on the front surface. Further, a second conductive contact is located over the front surface and is electrically connected to the second conductive structure. The conductive path can be formed by lithography and etching followed by metal deposition.

Semiconductor device structures with backside contacts for improved heat dissipation and reduced parasitic resistance

A self-aligned bipolar transistor structure having a raised extrinsic base comprising an outer region and an inner region of different doping concentrations and methods of fabricating the transistor are disclosed. More specifically, the self-alignment of the extrinsic base to the emitter is accomplished by forming the extrinsic base in two regions. First, a first material of silicon or polysilicon having a first doping concentration is provided to form an outer extrinsic base region. Then a first opening is formed in the first material layer by lithography within which a dummy emitter pedestal is formed, which results in forming a trench between the sidewall of the first opening and the dummy pedestal. A second material of a second doping concentration is then provided inside the trench forming a distinct inner extrinsic base extension region to self-align the raised extrinsic base edge to the dummy pedestal edge. Since the emitter is formed where the dummy pedestal existed, the extrinsic base is also self-aligned to the emitter. The silicon or polysilicon forming the inner extrinsic base extension region can also be grown in the trench with selective or non-selective epitaxy.

Bipolar transistor self-alignment with raised extrinsic base extension and methods of forming same

A bipolar transistor has a collector that is contacted directly beneath a base-collector junction by metallization to reduce collector resistance. A conventional reach-through and buried layer, as well as their associated resistance, are eliminated. The transistor is well isolated, nearly eliminating well-to-substrate capacitance and device-to-device leakage current. The structure provides for improved electrical performance, including improved f, Fmax and drive current.

Bipolar transistor with isolation and direct contacts

A system and method comprises forming an intrinsic base on a collector. The system and method further includes forming a fully silicided extrinsic base on the intrinsic base by a self-limiting silicidation process at a predetermined temperature and for a predetermined amount of time, the silicidation substantially stopping at the intrinsic base. The system and method further includes forming an emitter which is physically insulated from the extrinsic base and the collector, and which is in physical contact with the intrinsic base.

Fully silicided extrinsic base transistor

Disclosed are an improved hetero-junction bipolar transistor (HBT) structure and a method of forming the structure that incorporates a silicon-germanium emitter layer with a graded germanium profile. The graded germanium concentration creates a quasi-drift field in the neutral region of the emitter layer. This quasi-drift field induces valence bandgap grading within the emitter layer so as to accelerate movement of holes from the base layer through the emitter layer. Accelerated movement of the holes from the base layer through the emitter layer reduces emitter delay time and thereby, increases the cut-off frequency (f) and the maximum oscillation frequency (f) of the resultant HBT.

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Jefferson Valley, NY, United States of America

Francois Pagette